From gyre-Ja3L+HSX0kI at public.gmane.org Thu Aug 1 08:16:50 2013 From: gyre-Ja3L+HSX0kI at public.gmane.org (Eric) Date: Thu, 1 Aug 2013 04:16:50 -0400 (EDT) Subject: war story: parallel(1) command In-Reply-To: <20130731142626.GO11327-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <20130731142626.GO11327@csclub.uwaterloo.ca> Message-ID: On Wed, 31 Jul 2013, Lennart Sorensen wrote: > On Tue, Jul 30, 2013 at 06:33:44PM -0400, Eric B wrote: > > Your "likely the same" is context dependent. > > I agree with what you say above in the context of random file > > corruption or in the case of files containing random bits. > > > > For Hugh's case, he wants to hash all the files in a real filesystem > > to find real differences. > > > > If one calculates the SHA-N hash for each file, that would > > answer the question ("Are these files the same or different?") > > with virtual certainty. There is NO need for an additional > > compare if the same hash is found. > > Of course there is. If you don't, you simply indicate you have no > understanding of what a hash is. Did you follow the link Hugh's provided?: http://marc.info/?l=git&m=115678778717621&w=2 > > When probabilities are too astronomically unlikely, > > they never happen in reality. > > That's not good enough for file comparison. > > Of course you are unlikely to find two different files with the same > hash, so must likely the extra comparison won't happen on files that > are not the same, but you still need to do it. No, you do not need to do it, and doing it is a waste of time. If something does not happen in reality, there is no need to test for it. In the cases I am talking about, think of a collision as being so astronomically unlikely that it is indistinguishable from impossible. A distinction without a difference is not a real difference. Any other factual event in this universe is more likely to occur than such a collision. For all intents and purposes, a real collision is impossible. -- Eric B. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 1 23:02:19 2013 From: cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Christopher Browne) Date: Thu, 1 Aug 2013 19:02:19 -0400 Subject: war story: parallel(1) command In-Reply-To: References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <20130731142626.GO11327@csclub.uwaterloo.ca> Message-ID: On Thu, Aug 1, 2013 at 4:16 AM, Eric wrote: > On Wed, 31 Jul 2013, Lennart Sorensen wrote: > >> On Tue, Jul 30, 2013 at 06:33:44PM -0400, Eric B wrote: >> > Your "likely the same" is context dependent. >> > I agree with what you say above in the context of random file >> > corruption or in the case of files containing random bits. >> > >> > For Hugh's case, he wants to hash all the files in a real filesystem >> > to find real differences. >> > >> > If one calculates the SHA-N hash for each file, that would >> > answer the question ("Are these files the same or different?") >> > with virtual certainty. There is NO need for an additional >> > compare if the same hash is found. >> >> Of course there is. If you don't, you simply indicate you have no >> understanding of what a hash is. > > Did you follow the link Hugh's provided?: > http://marc.info/?l=git&m=115678778717621&w=2 > >> > When probabilities are too astronomically unlikely, >> > they never happen in reality. >> >> That's not good enough for file comparison. >> >> Of course you are unlikely to find two different files with the same >> hash, so must likely the extra comparison won't happen on files that >> are not the same, but you still need to do it. > > No, you do not need to do it, and doing it is a waste of time. > If something does not happen in reality, there is no need to test > for it. > > In the cases I am talking about, think of a collision as being so > astronomically unlikely that it is indistinguishable from > impossible. > A distinction without a difference is not a real difference. > Any other factual event in this universe is more likely > to occur than such a collision. > For all intents and purposes, a real collision is impossible. This seems in conflict with Cromwell's Rule... http://en.wikipedia.org/wiki/Cromwell%27s_rule The reference is to Oliver Cromwell. Cromwell wrote to the synod of the Church of Scotland on August 5 1650, including a phrase that has become well known and frequently quoted: "I beseech you, in the bowels of Christ, think it possible that you may be mistaken." As Lindley puts it, assigning a probability should "leave a little probability for the moon being made of green cheese; it can be as small as 1 in a million, but have it there since otherwise an army of astronauts returning with samples of the said cheese will leave you unmoved."[3] Similarly, in assessing the likelihood that tossing a coin will result in either a head or a tail facing upwards, there is a possibility, albeit remote, that the coin will land on its edge and remain in that position. While I agree that SHA-1 was designed to try to resist collisions, I do not think I have quite so much faith as you do as to the permanency or *true* impossibility of this. People thought that the Knapsack cipher was strong; it turned out not to be nearly as strong as imagined. It would be unfortunate if Git depended (to the point of falling apart destructively!) on the True Impossibility of SHA-1 collisions, only for us to discover, 10 years from now, that someone can induce collisions at some moderate computational cost, and, thereby, throw patches at Git repositories that make them fall over. I'm not making up a purely theoretical problem; note that cryptographers have found better-than-brute-force attacks already against SHA-1. The difficulty was reduced in 2005 from 2^80 calculations to 2^69. That's the sort of thing that theoretical cryptanalysis tends to achieve; moving from "toughest brute force" solutions to ones that reduce the solution space to something easier. Of course, "easier != easy"; 2^69 calculations is still a pretty material amount of work, more than what the distributed.net project did. But I think I rather go with Cromwell, and be a little paranoid that what, at this point, seems "impossible before the heat death of the universe" might prove more tractable. The Japanese apparently were mistaken as to how large the largest tsunami could be; they evidently treated something as impossible that was evidently rather less improbable. A few billion dollars of extra spending might have prevented what's estimated at > $200B in losses. When using hashing for uniqueness, I'm inclined to not treat collisions as being Truly Impossible, when we should well know that that isn't actually so. -- When confronted by a difficult problem, solve it by reducing it to the question, "How would the Lone Ranger handle this?" -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Fri Aug 2 02:22:21 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Thu, 01 Aug 2013 22:22:21 -0400 Subject: war story: parallel(1) command In-Reply-To: References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> Message-ID: <51FB17DD.7090009@rogers.com> D. Hugh Redelmeier wrote: > MD5 hashes are quite reasonably distributed over the 128-bit space. You'd > need something like 2^64 things for the birthday paradox to fire. Okay. You have 128 bit hash. That's 2^128 possible combinations. Now take a bunch of 1 KB (2^10) files. Those are 2^13 bits and 2^(2^13) combinations. That means for any given hash, you could have an extremely large number? of different files that size that could have the same hash. Granted, duplicate hashes are extremely rare, but you can never claim they're impossible. 1. The KDE calculator can't handle a number that large -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 2 14:23:17 2013 From: william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (William Muriithi) Date: Fri, 2 Aug 2013 10:23:17 -0400 Subject: Dspam effectiveness In-Reply-To: References: Message-ID: Hi, Curious, anyone here have tried both dspam and SpamAssassin? Just curious if its worth trying dspam. From Wikipedia, it don't seem such effective, but have meet people who imply its far better than SpamAssassin. Haven't been following either through mailing list and there isn't a lot of recent discussion of the topic which is important considering dspam seem to have been sold a number of times. Would be great if you could share your opinion William -------------- next part -------------- An HTML attachment was scrubbed... URL: From kalibslack-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 2 14:27:27 2013 From: kalibslack-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Marcelo Cavalcante) Date: Fri, 2 Aug 2013 11:27:27 -0300 Subject: Dspam effectiveness In-Reply-To: References: Message-ID: 2013/8/2 William Muriithi > Hi, > > Curious, anyone here have tried both dspam and SpamAssassin? Just curious > if its worth trying dspam. From Wikipedia, it don't seem such effective, > but have meet people who imply its far better than SpamAssassin. > > Haven't been following either through mailing list and there isn't a lot > of recent discussion of the topic which is important considering dspam seem > to have been sold a number of times. > > Would be great if you could share your opinion > > William > I'm not sure if you'll be able to find an effective solution against spam. Everything is such a mess right now. I tried many solutions, incluind SpamAssassin, but couldn't really be "free" of spams. In fact, not even close to it. Never tried dspam, so I can't tell about it, but I think it's hard to believe that this would be a real solution against spam. :/ =================================================== Marcelo Cavalcante Rocha - Kalib P?s-Graduando em Governan?a de Tecnologia da Informa??o - EST?CIO/FIC Graduado em Sistemas de Informa??es - EST?CIO/FIC Usu?rio Linux #407564 | Usu?rio Asterisk #1148 Fortaleza - Cear? - Brazil Celular: +55 085 87620983 Certifica??es: ITIL V3 | CSM | LPI-C1 | LPI-C2 | LPI-C3 | Novell CLA Minha Pessoa: Blog Projetos: Tux-CE | Archlinux-br | Chakra | KDE Brasil | TLUG | PUG-CE =================================================== Proteja meu endere?o como estou protegendo o seu. N?o revele e-mail dos correspondentes: use Cco (Copia Carbonada Oculta). Retire os endere?os antes de reenviar. Dificulte assim a dissemina??o de v?rus e spam. -------------- next part -------------- An HTML attachment was scrubbed... URL: From me-3ZSMZGRXU0K2dHQpreyxbg at public.gmane.org Fri Aug 2 14:29:18 2013 From: me-3ZSMZGRXU0K2dHQpreyxbg at public.gmane.org (staticsafe) Date: Fri, 2 Aug 2013 10:29:18 -0400 Subject: Dspam effectiveness In-Reply-To: References: Message-ID: <20130802142917.GB3333@uriel.asininetech.com> On Fri, Aug 02, 2013 at 10:23:17AM -0400, William Muriithi wrote: > Hi, > > Curious, anyone here have tried both dspam and SpamAssassin? Just curious > if its worth trying dspam. From Wikipedia, it don't seem such effective, > but have meet people who imply its far better than SpamAssassin. > > Haven't been following either through mailing list and there isn't a lot of > recent discussion of the topic which is important considering dspam seem to > have been sold a number of times. > > Would be great if you could share your opinion > > William I took a brief look at dspam when implementing my mail server's antispam system, but the documentation isn't that great, so I stuck with amavisd (which uses spamassassin libraries for antispam). -- staticsafe O< ascii ribbon campaign - stop html mail - www.asciiribbon.org Please don't top post. Please don't CC! I'm subscribed to whatever list I just posted on. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 2 15:09:58 2013 From: colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Colin McGregor) Date: Fri, 2 Aug 2013 11:09:58 -0400 Subject: Raspberry PI Power Message-ID: Sorry about a subject line that sounds like a tacky children's cartoon, but it is an issue I am looking at. I wanted to set-up a Raspberry PI with a 19" LCD screen at my kitchen table. Connected to the Raspberry PI I had an Ourlink WiFi dongle and a Logitech Unifying receiver to support a wireless keyboard/mouse (*). Initial set-up with several different "1 amp" output transformers had the same result, the Raspberry PI ran, but the WiFi connection was unusable. Powering the Raspberry PI off a 4 port USB hub that has a 2.6 amp power supply and moving the WiFi dongle to the hub has resulted in a very solid set-up. So, power seems to be the issue, but where is the question. Am I looking at : - a Raspberry PI with noted accessories using more than 1 amp of power? - transformers that claim to be "1 amp" not putting out 1 amp to the Raspberry PI? - a Raspberry PI getting enough power, but not being able to pass enough to the accessories? - another issue I have not thought of? My ideal goal here is to have a LITTLE machine (**) that will let me read on-line news headlines while having breakfast, so I would like to be rid of the USB hub, ideally without spending more $ (in case anyone asks, the USB hub power supply has an odd-ball connector so can't be re-used directly with the Raspberry PI and the USB hub was bought several years ago for a magazine article I was writing (ie: when buying that USB hub, use with a Raspberry PI wasn't a consideration)). Thoughts? Thanks Colin. (*) There is an issue with using both a keyboard and mouse with one Unifying receiver under Linux. The solution to the issue can be seen here : https://groups.google.com/forum/#!msg/linux.kernel/zYS6yddI8yU/9cMvg3k9xTYJ . (**) For the Raspberry PI I bought a case from these folks https://www.modmypi.com/shop . The nice thing about these cases is that you can screw them directly onto any monitor that has 75 mm VESA mounting holes (my 19" monitor being one such monitor). So, no Raspberry PI on the kitchen table, just a monitor that is now a bit thicker front to back... -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From scott-lxSQFCZeNF4 at public.gmane.org Fri Aug 2 16:02:14 2013 From: scott-lxSQFCZeNF4 at public.gmane.org (Scott Sullivan) Date: Fri, 02 Aug 2013 12:02:14 -0400 Subject: Raspberry PI Power In-Reply-To: References: Message-ID: <51FBD806.2010905@ss.org> On 08/02/2013 11:09 AM, Colin McGregor wrote: > Sorry about a subject line that sounds like a tacky children's > cartoon, but it is an issue I am looking at. > > I wanted to set-up a Raspberry PI with a 19" LCD screen at my kitchen > table. Connected to the Raspberry PI I had an Ourlink WiFi dongle and > a Logitech Unifying receiver to support a wireless keyboard/mouse (*). > Initial set-up with several different "1 amp" output transformers had > the same result, the Raspberry PI ran, but the WiFi connection was > unusable. Powering the Raspberry PI off a 4 port USB hub that has a > 2.6 amp power supply and moving the WiFi dongle to the hub has > resulted in a very solid set-up. So, power seems to be the issue, but > where is the question. Am I looking at : > > - a Raspberry PI with noted accessories using more than 1 amp of power? > - transformers that claim to be "1 amp" not putting out 1 amp to the > Raspberry PI? > - a Raspberry PI getting enough power, but not being able to pass > enough to the accessories? > - another issue I have not thought of? Colin, I assume you have a model B (as you have two USB ports). But which revision? The revision 1 boards had poly fuses that clamped the output of the USB ports to 100mA each. The USB spec only guarantees 100mA and the device is supposed to request more in 100mA increments up to 500mA. In practice this is largely ignored and the whole 500mA is usually provided. The Foundation was trying to be protective in the face of many 500-750mA chargers on the market at the time. But it cause more head scratching then problem solving. http://elinux.org/images/archive/9/96/20120908163029!RpiFront.jpg The revision 2 boards did away with them at community behest. http://elinux.org/images/9/96/RpiFront.jpg I had the same experience with my revision 1 board. You actually can by-pass the poly fuses (the two large green component in the top right corner of the board). You just need to solder a wire in place. Example: http://imgur.com/a/mIhaR -- Scott Sullivan -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 2 16:14:24 2013 From: colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Colin McGregor) Date: Fri, 2 Aug 2013 12:14:24 -0400 Subject: Raspberry PI Power In-Reply-To: <51FBD806.2010905-lxSQFCZeNF4@public.gmane.org> References: <51FBD806.2010905@ss.org> Message-ID: On Fri, Aug 2, 2013 at 12:02 PM, Scott Sullivan wrote: > On 08/02/2013 11:09 AM, Colin McGregor wrote: >> >> Sorry about a subject line that sounds like a tacky children's >> cartoon, but it is an issue I am looking at. >> >> I wanted to set-up a Raspberry PI with a 19" LCD screen at my kitchen >> table. Connected to the Raspberry PI I had an Ourlink WiFi dongle and >> a Logitech Unifying receiver to support a wireless keyboard/mouse (*). >> Initial set-up with several different "1 amp" output transformers had >> the same result, the Raspberry PI ran, but the WiFi connection was >> unusable. Powering the Raspberry PI off a 4 port USB hub that has a >> 2.6 amp power supply and moving the WiFi dongle to the hub has >> resulted in a very solid set-up. So, power seems to be the issue, but >> where is the question. Am I looking at : >> >> - a Raspberry PI with noted accessories using more than 1 amp of power? >> - transformers that claim to be "1 amp" not putting out 1 amp to the >> Raspberry PI? >> - a Raspberry PI getting enough power, but not being able to pass >> enough to the accessories? >> - another issue I have not thought of? > > > Colin, > > I assume you have a model B (as you have two USB ports). But which revision? Revision 2, with 512 MB of RAM, made in the UK, so board revision doesn't seem to be the issue. Thanks for the thought though. > The revision 1 boards had poly fuses that clamped the output of the USB > ports to 100mA each. The USB spec only guarantees 100mA and the device is > supposed to request more in 100mA increments up to 500mA. In practice this > is largely ignored and the whole 500mA is usually provided. The Foundation > was trying to be protective in the face of many 500-750mA chargers on the > market at the time. But it cause more head scratching then problem solving. > > http://elinux.org/images/archive/9/96/20120908163029!RpiFront.jpg > > The revision 2 boards did away with them at community behest. > > http://elinux.org/images/9/96/RpiFront.jpg > > I had the same experience with my revision 1 board. You actually can by-pass > the poly fuses (the two large green component in the top right corner of the > board). You just need to solder a wire in place. > > Example: > http://imgur.com/a/mIhaR > -- > Scott Sullivan > > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From gyre-Ja3L+HSX0kI at public.gmane.org Fri Aug 2 16:24:32 2013 From: gyre-Ja3L+HSX0kI at public.gmane.org (Eric) Date: Fri, 2 Aug 2013 12:24:32 -0400 (EDT) Subject: war story: parallel(1) command In-Reply-To: <51FB17DD.7090009-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> Message-ID: On Thu, 1 Aug 2013, James Knott wrote: > D. Hugh Redelmeier wrote: > > MD5 hashes are quite reasonably distributed over the 128-bit space. You'd > > need something like 2^64 things for the birthday paradox to fire. > > Okay. You have 128 bit hash. That's 2^128 possible combinations. Now > take a bunch of 1 KB (2^10) files. Those are 2^13 bits and 2^(2^13) > combinations. That means for any given hash, you could have an > extremely large number of different files that size that could have the > same hash. Granted, duplicate hashes are extremely rare, but you can > never claim they're impossible. Are you arguing about this specific case, or the principle? To make it clear, consider an extreme example: If an event has a probability of occurring once in a googolplex universe lifetimes, will that occur in reality? Of course, not. Next, is that worth wasting CPU/IO/real time programming for it because someone says "It is not impossible."? > 1. The KDE calculator can't handle a number that large Use 'bc' or Perl with 'bignum': $ perl -le 'use bignum; print 2**128' 340282366920938463463374607431768211456 -- Eric B. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From gyre-Ja3L+HSX0kI at public.gmane.org Fri Aug 2 16:33:31 2013 From: gyre-Ja3L+HSX0kI at public.gmane.org (Eric) Date: Fri, 2 Aug 2013 12:33:31 -0400 (EDT) Subject: war story: parallel(1) command In-Reply-To: References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <20130731142626.GO11327@csclub.uwaterloo.ca> Message-ID: On Thu, 1 Aug 2013, Christopher Browne wrote: > While I agree that SHA-1 was designed to try to resist collisions, I > do not think I have quite so much faith as you do as to the permanency > or *true* impossibility of this. > > People thought that the Knapsack cipher was strong; it turned out not > to be nearly as strong as imagined. It would be unfortunate if Git > depended (to the point of falling apart destructively!) on the True > Impossibility of SHA-1 collisions, only for us to discover, 10 years > from now, that someone can induce collisions at some moderate > computational cost, and, thereby, throw patches at Git repositories > that make them fall over. I agree. My argument was not tied specifically to SHA-1. > But I think I rather go with Cromwell, and be a little paranoid that > what, at this point, seems "impossible before the heat death of the > universe" might prove more tractable. Yes, then the initial mathematical assumptions were wrong. In that case argue the math, not the probabilities. -- Eric B. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From williamdweaver-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 2 16:46:19 2013 From: williamdweaver-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (William Weaver) Date: Fri, 2 Aug 2013 12:46:19 -0400 Subject: Raspberry PI Power In-Reply-To: References: <51FBD806.2010905@ss.org> Message-ID: Colin, My bet is that the logitech unifying receiver and the wifi are both requesting a high current usb connection, which is then saturating your 1A power source when the RPis load gets high. Would it be possible for you to measure your current draw from the externally powered power supply? Also something I've been doing, I have a monitor with USB built into it, I plug my power cable from the pi into the monitor powered USB hub, then the ubhub into the pi. The pi gets power from the usb hub (which doesn't have a data line so it doesn't create a loop issue, and the other ports are available for usage. Best of all my monitor's power switch becomes a hard power switch for the pi. In your case you may be able to take the usb hub and with a bit of soldering put it on one of the rails of the lcds power supply. I'd definately check spec sheets and do some testing before you broke out the iron though. Will On Fri, Aug 2, 2013 at 12:14 PM, Colin McGregor wrote: > On Fri, Aug 2, 2013 at 12:02 PM, Scott Sullivan wrote: > > On 08/02/2013 11:09 AM, Colin McGregor wrote: > >> > >> Sorry about a subject line that sounds like a tacky children's > >> cartoon, but it is an issue I am looking at. > >> > >> I wanted to set-up a Raspberry PI with a 19" LCD screen at my kitchen > >> table. Connected to the Raspberry PI I had an Ourlink WiFi dongle and > >> a Logitech Unifying receiver to support a wireless keyboard/mouse (*). > >> Initial set-up with several different "1 amp" output transformers had > >> the same result, the Raspberry PI ran, but the WiFi connection was > >> unusable. Powering the Raspberry PI off a 4 port USB hub that has a > >> 2.6 amp power supply and moving the WiFi dongle to the hub has > >> resulted in a very solid set-up. So, power seems to be the issue, but > >> where is the question. Am I looking at : > >> > >> - a Raspberry PI with noted accessories using more than 1 amp of power? > >> - transformers that claim to be "1 amp" not putting out 1 amp to the > >> Raspberry PI? > >> - a Raspberry PI getting enough power, but not being able to pass > >> enough to the accessories? > >> - another issue I have not thought of? > > > > > > Colin, > > > > I assume you have a model B (as you have two USB ports). But which > revision? > > Revision 2, with 512 MB of RAM, made in the UK, so board revision > doesn't seem to be the issue. > > Thanks for the thought though. > > > The revision 1 boards had poly fuses that clamped the output of the USB > > ports to 100mA each. The USB spec only guarantees 100mA and the device is > > supposed to request more in 100mA increments up to 500mA. In practice > this > > is largely ignored and the whole 500mA is usually provided. The > Foundation > > was trying to be protective in the face of many 500-750mA chargers on the > > market at the time. But it cause more head scratching then problem > solving. > > > > http://elinux.org/images/archive/9/96/20120908163029!RpiFront.jpg > > > > The revision 2 boards did away with them at community behest. > > > > http://elinux.org/images/9/96/RpiFront.jpg > > > > I had the same experience with my revision 1 board. You actually can > by-pass > > the poly fuses (the two large green component in the top right corner of > the > > board). You just need to solder a wire in place. > > > > Example: > > http://imgur.com/a/mIhaR > > -- > > Scott Sullivan > > > > -- > > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -------------- next part -------------- An HTML attachment was scrubbed... URL: From kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org Fri Aug 2 17:15:05 2013 From: kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org (Kevin Cozens) Date: Fri, 02 Aug 2013 13:15:05 -0400 Subject: Raspberry PI Power In-Reply-To: References: Message-ID: <51FBE919.8040204@ve3syb.ca> On 13-08-02 11:09 AM, Colin McGregor wrote: > Initial set-up with several different "1 amp" output transformers had > the same result, the Raspberry PI ran, but the WiFi connection was > unusable. Powering the Raspberry PI off a 4 port USB hub that has a > 2.6 amp power supply and moving the WiFi dongle to the hub has > resulted in a very solid set-up. The first thing to do is check the voltages on the Pi board. I'm also using a Pi with an OurLink WiFi adapter. I am using a 1 amp power supply. The voltage before and after inserting the WiFi adapter didn't change much. It was a bit low but still above (but near) the low end of the 5V range for the Pi. When I tried to connect, the router saw the DHCP request from the Pi but the Pi never got its IP address. The router I was using at the time was a D-Link DI-524 (an oldie but reliable for me for about 8 years). The D-Link router recently started acting up so I replaced it with a Netgear router and the Pi, OurLink adapter, and same power supply was now working. The Pi was able to obtain an IP address over WiFi. I don't know why the change in router made a difference but it did in my case. -- Cheers! Kevin. http://www.ve3syb.ca/ |"Nerds make the shiny things that distract Owner of Elecraft K2 #2172 | the mouth-breathers, and that's why we're | powerful!" #include | --Chris Hardwick -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From softquake-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 2 17:24:36 2013 From: softquake-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Zbigniew Koziol) Date: Fri, 02 Aug 2013 21:24:36 +0400 Subject: Raspberry PI Power In-Reply-To: References: <51FBD806.2010905@ss.org> Message-ID: <51FBEB54.9040109@gmail.com> On 02/08/13 20:46, William Weaver wrote: > Colin, > > My bet is that the logitech unifying receiver and the wifi are both > requesting a high current usb connection, which is then saturating > your 1A power source when the RPis load gets high. Would it be > possible for you to measure your current draw from the externally > powered power supply? It is much easier to measure voltage than current. For this one may connect voltmeter to two points where the first capacitor is connected, just after USB power supplier. I have for instance the following results: When no any USB is connected, and nothing else, voltage is 5.18 V with my USB power supplier. When I connect USB keyboard only - voltage drops to 5.17 When I connect SSD card only - voltage drops to 5.15 V With USB keyboard, SSD card and wireless UB mouse - voltage remains 5.15. These results do not prove much but could indicate on a problem. Actually, I do have a problem. I would expect that after connecting keyboard I should have some response from it (LED lights up/down on keyboard after CapsLock is pressed, etc). Unfortunately, I do not see that. [...] zb. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From williamdweaver-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 2 17:39:47 2013 From: williamdweaver-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (William Weaver) Date: Fri, 2 Aug 2013 13:39:47 -0400 Subject: Raspberry PI Power In-Reply-To: <51FBEB54.9040109-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> References: <51FBD806.2010905@ss.org> <51FBEB54.9040109@gmail.com> Message-ID: I totally agree that it's easier to measure the Voltage than the current, the problem is for the situation the RPi is going to keep the voltage constant on the 5V rail. It'll do that by upping the current draw, if he's capping out the 1A power draw of the supply, he won't know that unless you either get a current measurement or you can accurately determine the power draw of the USB port. Then you have P = VI. Putting two leads inline a USB connector to get a current measurement shouldn't be to terrible. Will On Fri, Aug 2, 2013 at 1:24 PM, Zbigniew Koziol wrote: > On 02/08/13 20:46, William Weaver wrote: > >> Colin, >> >> My bet is that the logitech unifying receiver and the wifi are both >> requesting a high current usb connection, which is then saturating your 1A >> power source when the RPis load gets high. Would it be possible for you to >> measure your current draw from the externally powered power supply? >> > > It is much easier to measure voltage than current. For this one may > connect voltmeter to two points where the first capacitor is connected, > just after USB power supplier. I have for instance the following results: > > When no any USB is connected, and nothing else, voltage is 5.18 V with my > USB power supplier. > When I connect USB keyboard only - voltage drops to 5.17 > When I connect SSD card only - voltage drops to 5.15 V > With USB keyboard, SSD card and wireless UB mouse - voltage remains 5.15. > > These results do not prove much but could indicate on a problem. > > Actually, I do have a problem. I would expect that after connecting > keyboard I should have some response from it (LED lights up/down on > keyboard after CapsLock is pressed, etc). Unfortunately, I do not see that. > > [...] > > zb. > > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/**Mailing_lists > -------------- next part -------------- An HTML attachment was scrubbed... URL: From cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 2 17:40:03 2013 From: cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Christopher Browne) Date: Fri, 2 Aug 2013 13:40:03 -0400 Subject: Interesting paper on economic analysis of open source 3D printing Message-ID: http://www.academia.edu/4067796/Life-Cycle_Economic_Analysis_of_Distributed_Manufacturing_with_Open-Source_3-D_Printers The table near the end of the paper reports a series of objects that they suggest one might be likely to build over the course of a couple of years; it is quite an interesting set, albeit a little bit iDevice centric... -- When confronted by a difficult problem, solve it by reducing it to the question, "How would the Lone Ranger handle this?" -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org Fri Aug 2 17:55:17 2013 From: jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org (Jamon Camisso) Date: Fri, 02 Aug 2013 13:55:17 -0400 Subject: Dspam effectiveness In-Reply-To: <23269_1375453773_r72ETXBS026373_20130802142917.GB3333-dsyQKypJCoUP4pBOfwUP2bVn/6FJ7LQa@public.gmane.org> References: <23269_1375453773_r72ETXBS026373_20130802142917.GB3333@uriel.asininetech.com> Message-ID: <51FBF285.9060805@utoronto.ca> On 02/08/13 10:29 AM, staticsafe wrote: > On Fri, Aug 02, 2013 at 10:23:17AM -0400, William Muriithi wrote: >> Curious, anyone here have tried both dspam and SpamAssassin? Just curious >> if its worth trying dspam. From Wikipedia, it don't seem such effective, >> but have meet people who imply its far better than SpamAssassin. >> >> Haven't been following either through mailing list and there isn't a lot of >> recent discussion of the topic which is important considering dspam seem to >> have been sold a number of times. > > I took a brief look at dspam when implementing my mail server's antispam > system, but the documentation isn't that great, so I stuck with amavisd > (which uses spamassassin libraries for antispam). There are a few techniques that you can use before you even accept a message. I use a combination of Postscreen, remote block lists, and greylisting. I don't check inbound DKIM/SPF records, but those are useful if you want to use spamassassin as they are a good indicator of a valid message. Take a look here for more info on these tools: https://workaround.org/book/export/html/384 Postscreen is relatively new but is very effective on a high volume mail server. http://www.postfix.org/POSTSCREEN_README.html Cheers, Jamon -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From me-3ZSMZGRXU0K2dHQpreyxbg at public.gmane.org Fri Aug 2 19:11:24 2013 From: me-3ZSMZGRXU0K2dHQpreyxbg at public.gmane.org (staticsafe) Date: Fri, 2 Aug 2013 15:11:24 -0400 Subject: Dspam effectiveness In-Reply-To: <51FBF285.9060805-H217xnMUJC0sA/PxXw9srA@public.gmane.org> References: <23269_1375453773_r72ETXBS026373_20130802142917.GB3333@uriel.asininetech.com> <51FBF285.9060805@utoronto.ca> Message-ID: <20130802191124.GC3333@uriel.asininetech.com> On Fri, Aug 02, 2013 at 01:55:17PM -0400, Jamon Camisso wrote: > On 02/08/13 10:29 AM, staticsafe wrote: > > On Fri, Aug 02, 2013 at 10:23:17AM -0400, William Muriithi wrote: > >> Curious, anyone here have tried both dspam and SpamAssassin? Just curious > >> if its worth trying dspam. From Wikipedia, it don't seem such effective, > >> but have meet people who imply its far better than SpamAssassin. > >> > >> Haven't been following either through mailing list and there isn't a lot of > >> recent discussion of the topic which is important considering dspam seem to > >> have been sold a number of times. > > > > I took a brief look at dspam when implementing my mail server's antispam > > system, but the documentation isn't that great, so I stuck with amavisd > > (which uses spamassassin libraries for antispam). > > There are a few techniques that you can use before you even accept a > message. I use a combination of Postscreen, remote block lists, and > greylisting. I don't check inbound DKIM/SPF records, but those are > useful if you want to use spamassassin as they are a good indicator of a > valid message. > > Take a look here for more info on these tools: > https://workaround.org/book/export/html/384 > > Postscreen is relatively new but is very effective on a high volume mail > server. http://www.postfix.org/POSTSCREEN_README.html > > Cheers, Jamon I use a similar setup as well. Postscreen with some blacklists/whitelists for IP reputation based filtering and amavisd for content filtering. Content filtering isn't really needed that much for my purposes as I do not receive enough spam to feed the SA Bayes DB, most of my mail (mailing lists) is ham. $ sa-learn --dump magic | egrep "spam|ham" 0.000 0 130 0 non-token data: nspam 0.000 0 84966 0 non-token data: nham # Postscreen config postscreen_dnsbl_sites = zen.spamhaus.org*3 b.barracudacentral.org*2 bl.spameatingmonkey.net*2 dnsbl.ahbl.org bl.spamcop.net dnsbl.sorbs.net swl.spamhaus.org*-4 list.dnswl.org=127.[0..255].[0..255].0*-2 list.dnswl.org=127.[0..255].[0..255].1*-3 list.dnswl.org=127.[0..255].[0..255].[2..255]*-4 -- staticsafe O< ascii ribbon campaign - stop html mail - www.asciiribbon.org Please don't top post. Please don't CC! I'm subscribed to whatever list I just posted on. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org Fri Aug 2 19:42:30 2013 From: jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org (Jamon Camisso) Date: Fri, 02 Aug 2013 15:42:30 -0400 Subject: war story: parallel(1) command In-Reply-To: <30270_1375460888_r72GS7qn031201_alpine.NEB.2.00.1308021153360.12729-Ja3L+HSX0kI@public.gmane.org> References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <30270_1375460888_r72GS7qn031201_alpine.NEB.2.00.1308021153360.12729@vex.net> Message-ID: <51FC0BA6.3020103@utoronto.ca> On 02/08/13 12:24 PM, Eric wrote: > On Thu, 1 Aug 2013, James Knott wrote: > >> D. Hugh Redelmeier wrote: >>> MD5 hashes are quite reasonably distributed over the 128-bit space. You'd >>> need something like 2^64 things for the birthday paradox to fire. >> >> Okay. You have 128 bit hash. That's 2^128 possible combinations. Now >> take a bunch of 1 KB (2^10) files. Those are 2^13 bits and 2^(2^13) >> combinations. That means for any given hash, you could have an >> extremely large number of different files that size that could have the >> same hash. Granted, duplicate hashes are extremely rare, but you can >> never claim they're impossible. > > Are you arguing about this specific case, or the principle? > > To make it clear, consider an extreme example: > If an event has a probability of > occurring once in a googolplex universe lifetimes, will that > occur in reality? Of course, not. > > Next, is that worth wasting CPU/IO/real time programming for > it because someone says "It is not impossible."? Absolutely. We invented digital computers to externalize computational work for us as a society because it is faster and more efficient than doing it by hand or with a slide rule. As such, we ought to use computers to do work, like checking the results of algorithms that are good enough for most intents and purposes, but not all, even accounting for an outlier in a 2^128 space. For example, a forensic analysis of a filesystem would have to show with absolute certainty that any hash collision, however remotely improbable in any infinite number of universes' lifetimes, has been documented, files compared and accounted for. Close enough is just not good enough, and as was originally pointed out, file I/O is the bottleneck, not CPU. So once a file is read, might as well account for even the remote possibilities with a few extra CPU loops. Jamon -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From mlxxxp-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 2 19:42:56 2013 From: mlxxxp-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Scott Allen) Date: Fri, 2 Aug 2013 15:42:56 -0400 Subject: Raspberry PI Power In-Reply-To: References: <51FBD806.2010905@ss.org> <51FBEB54.9040109@gmail.com> Message-ID: On 2 August 2013 13:39, William Weaver wrote: > I totally agree that it's easier to measure the Voltage than the current, > the problem is for the situation the RPi is going to keep the voltage > constant on the 5V rail. No. The RPi requires a regulated 5V input. It's up to the power supply to keep the voltage constant at 5V regardless of the current draw. If the RPi and whatever else is being powered requires more current than the supply can provide, then either the voltage will drop or the power supply will blow a fuse, shut down, or burn out, depending on the supply's design. Thus, measuring the voltage under full load is a valid way of determining if the supply can provide adequate current. Note, though, that using a meter to do this won't show any ripple. It's possible that under high load the ripple voltage on the supply will be out of tolerance and cause problems. You would need an oscilloscope to show this, but the same goes for current measurements. -- Scott -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From mlxxxp-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 2 20:26:18 2013 From: mlxxxp-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Scott Allen) Date: Fri, 2 Aug 2013 16:26:18 -0400 Subject: Raspberry PI Power In-Reply-To: References: <51FBD806.2010905@ss.org> <51FBEB54.9040109@gmail.com> Message-ID: On 2 August 2013 15:42, Scott Allen wrote: > It's possible > that under high load the ripple voltage on the supply will be out of > tolerance and cause problems. I should have mentioned that, in addition to ripple, the power supply's transient response can be an issue. A slow transient response can cause voltage dips and spikes when the current draw rapidly changes. Again, like ripple, this is something that you would need an oscilloscope (or some other high bandwidth voltage min/max detector) to see. A standard voltmeter wouldn't show it. -- Scott -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From mike.kallies-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 2 21:17:21 2013 From: mike.kallies-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Mike Kallies) Date: Fri, 02 Aug 2013 17:17:21 -0400 Subject: Raspberry PI Power In-Reply-To: References: <51FBD806.2010905@ss.org> <51FBEB54.9040109@gmail.com> Message-ID: <51FC21E1.5060608@gmail.com> On 02/08/2013 4:26 PM, Scott Allen wrote: ... > Again, like ripple, this is something that you would need an > oscilloscope (or some other high bandwidth voltage min/max detector) > to see. A standard voltmeter wouldn't show it. There was a really great article about this a while back: http://www.righto.com/2012/10/a-dozen-usb-chargers-in-lab-apple-is.html Detailed graphs of the power/voltage and overload characteristics of a breadth of chargers. -Mike -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From tjaviss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 2 21:42:26 2013 From: tjaviss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Tyler Aviss) Date: Fri, 2 Aug 2013 14:42:26 -0700 Subject: Raspberry PI Power In-Reply-To: References: Message-ID: I've run into similar issues with my pi. Wifi isn't very happy despite my using a charger (from my Nexus 7) that is supposed to provide 2a On Aug 2, 2013 8:10 AM, "Colin McGregor" wrote: > Sorry about a subject line that sounds like a tacky children's > cartoon, but it is an issue I am looking at. > > I wanted to set-up a Raspberry PI with a 19" LCD screen at my kitchen > table. Connected to the Raspberry PI I had an Ourlink WiFi dongle and > a Logitech Unifying receiver to support a wireless keyboard/mouse (*). > Initial set-up with several different "1 amp" output transformers had > the same result, the Raspberry PI ran, but the WiFi connection was > unusable. Powering the Raspberry PI off a 4 port USB hub that has a > 2.6 amp power supply and moving the WiFi dongle to the hub has > resulted in a very solid set-up. So, power seems to be the issue, but > where is the question. Am I looking at : > > - a Raspberry PI with noted accessories using more than 1 amp of power? > - transformers that claim to be "1 amp" not putting out 1 amp to the > Raspberry PI? > - a Raspberry PI getting enough power, but not being able to pass > enough to the accessories? > - another issue I have not thought of? > > My ideal goal here is to have a LITTLE machine (**) that will let me > read on-line news headlines while having breakfast, so I would like to > be rid of the USB hub, ideally without spending more $ (in case anyone > asks, the USB hub power supply has an odd-ball connector so can't be > re-used directly with the Raspberry PI and the USB hub was bought > several years ago for a magazine article I was writing (ie: when > buying that USB hub, use with a Raspberry PI wasn't a consideration)). > > Thoughts? > > Thanks > > > > Colin. > > (*) There is an issue with using both a keyboard and mouse with one > Unifying receiver under Linux. The solution to the issue can be seen > here : > https://groups.google.com/forum/#!msg/linux.kernel/zYS6yddI8yU/9cMvg3k9xTYJ > . > > (**) For the Raspberry PI I bought a case from these folks > https://www.modmypi.com/shop . The nice thing about these cases is > that you can screw them directly onto any monitor that has 75 mm VESA > mounting holes (my 19" monitor being one such monitor). So, no > Raspberry PI on the kitchen table, just a monitor that is now a bit > thicker front to back... > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -------------- next part -------------- An HTML attachment was scrubbed... URL: From kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org Fri Aug 2 22:02:28 2013 From: kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org (Kevin Cozens) Date: Fri, 02 Aug 2013 18:02:28 -0400 Subject: Raspberry PI Power In-Reply-To: <51FC21E1.5060608-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> References: <51FBD806.2010905@ss.org> <51FBEB54.9040109@gmail.com> <51FC21E1.5060608@gmail.com> Message-ID: <51FC2C74.2090605@ve3syb.ca> On 13-08-02 05:17 PM, Mike Kallies wrote: > http://www.righto.com/2012/10/a-dozen-usb-chargers-in-lab-apple-is.html > > Detailed graphs of the power/voltage and overload characteristics of a > breadth of chargers. A comment to the article mentioned the audible noise some of these devices can generate. The article didn't get in to the amount of unwanted RF that can be generated by cheap devices. I recently saw a YouTube video where a person showed a real vs. a cheap/fake camcorder charger. There was an AM radio playing a few feet from the chargers. When the cheap/fake charger was plugged in the AM radio station was almost wiped out by RF noise. The real charger did not affect the radio at all. -- Cheers! Kevin. http://www.ve3syb.ca/ |"Nerds make the shiny things that distract Owner of Elecraft K2 #2172 | the mouth-breathers, and that's why we're | powerful!" #include | --Chris Hardwick -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Sat Aug 3 03:31:42 2013 From: colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Colin McGregor) Date: Fri, 2 Aug 2013 23:31:42 -0400 Subject: Raspberry PI Power In-Reply-To: References: <51FBD806.2010905@ss.org> <51FBEB54.9040109@gmail.com> Message-ID: On Fri, Aug 2, 2013 at 3:42 PM, Scott Allen wrote: > On 2 August 2013 13:39, William Weaver wrote: >> I totally agree that it's easier to measure the Voltage than the current, >> the problem is for the situation the RPi is going to keep the voltage >> constant on the 5V rail. > > No. The RPi requires a regulated 5V input. It's up to the power supply > to keep the voltage constant at 5V regardless of the current draw. If > the RPi and whatever else is being powered requires more current than > the supply can provide, then either the voltage will drop or the power > supply will blow a fuse, shut down, or burn out, depending on the > supply's design. > > Thus, measuring the voltage under full load is a valid way of > determining if the supply can provide adequate current. Note, though, > that using a meter to do this won't show any ripple. It's possible > that under high load the ripple voltage on the supply will be out of > tolerance and cause problems. You would need an oscilloscope to show > this, but the same goes for current measurements. Well... Times that an oscilloscope would be useful to me only happen once in a blue moon, and with a price even for a VERY basic oscilloscope (such as the one designed by our local Peter Hiscock) being almost $200, well I just can't cost justify that when diagnosing (note, diagnosing, not fixing) a problem with a $35 (US) computer... Nice thought though. Anyone with a Raspberry PI and an oscilloscope want to take a crack at this? Colin > -- > Scott > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Sat Aug 3 17:03:11 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Sat, 3 Aug 2013 13:03:11 -0400 (EDT) Subject: understanding probability[was Re: war story: parallel(1) command] In-Reply-To: <51FC0BA6.3020103-H217xnMUJC0sA/PxXw9srA@public.gmane.org> References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <30270_1375460888_r72GS7qn031201_alpine.NEB.2.00.1308021153360.12729@vex.net> <51FC0BA6.3020103@utoronto.ca> Message-ID: | From: Jamon Camisso | Absolutely. We invented digital computers to externalize computational | work for us as a society because it is faster and more efficient than | doing it by hand or with a slide rule. We invented the computer to do calculations that were not feasible otherwise. I think that it is more of a surprise that we now make them so inexpensively that they can take on computations just for our convenience or entertainment. The first computers cost much more than houses. Now the cheapest ones are throw-away. | As such, we ought to use computers to do work, like checking the results | of algorithms that are good enough for most intents and purposes, but | not all, even accounting for an outlier in a 2^128 space. That logic is a bit iffy. The phrase "Good enough", in our world, often applies to 90% solutions. The chance of two distinct files having the same MD5 sum in a pool of n files is n * (n-1) / 2 ^ 128 (assuming MD5 is "good"). I was testing 800 files. $ bc -l scale=50 800 * (800 -1) / 2 ^ 128 .00000000000000000000000000000000187843997261401543 That's qualitatively different from 10% (100%-90%). Do you know how your crypto works? It uses industrial-grade primes: those are only very very probably primes. In these probabilistic things, you get to turn a knob: the more work you do, the more probably correct the result is. That's actually a great property. But you can never get to 100% and there is rarely a need to. All physical world things are uncertain to a much greater extent. | For example, a forensic analysis of a filesystem would have to show with | absolute certainty that any hash collision, however remotely improbable | in any infinite number of universes' lifetimes, has been documented, | files compared and accounted for. If you are going in front of a jury, probabilities are not going to be easy to deal with. Yet that is just what DNA evidence involves. But I'm not going to a jury trial over catching duplicate files on my disk drive. When it comes down to it, it's a matter of intuition and abstraction. It is a lot harder to keep uncertainty in ones mind. I would claim that .00000000000000000000000000000000187843997261401543 isn't uncertain in a practical sense. So I'm willing to classify that as impossible in my mind. The probablility of undetected read errors on a disk drive is much much higher and hence eclipses this one. | Close enough is just not good enough, and as was originally pointed out, | file I/O is the bottleneck, not CPU. So once a file is read, might as | well account for even the remote possibilities with a few extra CPU loops. Quibble: the work may be significantly greater. For example, if every file is duplicated once (a common case, not a worst case), you are doubling the file I/O, which we agree is the bottleneck in my case. Furthermore, the file I/O will no longer be purely sequential, so disk seeking might become significant in this step. And there is more coding required. I will admit sympathy for your position. I'm not really comfortable with floating point arithmetic for a similar reason. A large part of the field of numerical analysis is about figuring out how error bounds accumulate. Much calculation depends on the fact that the actual errors are not nearly as bad as the worst-case. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From softquake-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Sat Aug 3 18:02:22 2013 From: softquake-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Zbigniew Koziol) Date: Sat, 03 Aug 2013 22:02:22 +0400 Subject: understanding probability[was Re: war story: parallel(1) command] In-Reply-To: References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <30270_1375460888_r72GS7qn031201_alpine.NEB.2.00.1308021153360.12729@vex.net> <51FC0BA6.3020103@utoronto.ca> Message-ID: <51FD45AE.3010306@gmail.com> On 03/08/13 21:03, D. Hugh Redelmeier wrote: [...] In general, people do not have an idea and imagination how to deal with huge numbers. Bad physics teaching, I guess ;) (*) Once a young engineer worked with me (in Canada). He desined a database system that kept data from GPS related to vehicles mooving accross USA/Canada roads with an accuracy to... 1 picometer. Well.. but accuracy of GPS was of the order of 10 m. Good that he was so careful about accuracy but bad for database performance. How many atoms are in the Universe? 10^78 to 10^82 How that compares with 2^528 ? (*) Physics is not and never was about numbers. It is about understanding what is and what is not practically possible. With some probability, of course ;) I am not a specialist on law excercised at courts. But in case of doubt they are likely to ask an opinion of a specialist. -------------- next part -------------- An HTML attachment was scrubbed... URL: From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Sat Aug 3 19:04:21 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Sat, 03 Aug 2013 15:04:21 -0400 Subject: understanding probability[was Re: war story: parallel(1) command] In-Reply-To: <51FD45AE.3010306-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <30270_1375460888_r72GS7qn031201_alpine.NEB.2.00.1308021153360.12729@vex.net> <51FC0BA6.3020103@utoronto.ca> <51FD45AE.3010306@gmail.com> Message-ID: <51FD5435.4040501@rogers.com> Zbigniew Koziol wrote: > Physics is not and never was about numbers. It is about understanding > what is and what is not practically possible That lack of understanding is why some people believe in that nonsense called homeopathy. They dilute something to physically impossible levels and claim it cures something. It's also why many believe in religion rather than reality. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Sat Aug 3 19:19:49 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Sat, 03 Aug 2013 15:19:49 -0400 Subject: war story: parallel(1) command In-Reply-To: References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> Message-ID: <51FD57D5.60000@rogers.com> Eric wrote: > To make it clear, consider an extreme example: > If an event has a probability of > occurring once in a googolplex universe lifetimes, will that > occur in reality? Of course, not. And I suppose the Leafs may win the Stanley Cup some day. ;-) However, my understanding about probabilities says that while something may be unlikely, it's not impossible and, according to chance may even happen immediately. The astrophysicist Brian Greene has some interesting comments on this sort of thing, in the realm of infinite universes. One thing he mentions is that if the universe is truly infinite, then some subset of it, such as the portion within our obversable limits, must be repeated an infinite number of times. Another thing he mentioned was if you shuffle a deck of cards, while highly unlikely, one possible outcome is all the cards will be properly sorted. This is because no matter how many there are, there are a finite number of possible combinations. Once you've shuffled past that number of times, and likely well before it, then repeat sequences are inevitable. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From softquake-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Sat Aug 3 19:29:52 2013 From: softquake-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Zbigniew Koziol) Date: Sat, 03 Aug 2013 23:29:52 +0400 Subject: understanding probability[was Re: war story: parallel(1) command] In-Reply-To: <51FD5435.4040501-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <30270_1375460888_r72GS7qn031201_alpine.NEB.2.00.1308021153360.12729@vex.net> <51FC0BA6.3020103@utoronto.ca> <51FD45AE.3010306@gmail.com> <51FD5435.4040501@rogers.com> Message-ID: <51FD5A30.5020409@gmail.com> On 03/08/13 23:04, James Knott wrote: > Zbigniew Koziol wrote: >> Physics is not and never was about numbers. It is about understanding >> what is and what is not practically possible > That lack of understanding is why some people believe in that nonsense > called homeopathy. They dilute something to physically impossible > levels and claim it cures something. It's also why many believe in > religion rather than reality. James, I am a sort of materialist in my thinking. But I am not only that. Do not trivialise and do not mix different ways of understanding. Canada life and propaganda did such a mix of people thinking that it is unimaginable. I really do not want to bring examples that would be too personal and devastaing (some literalelly tragical to me), but possibly still not understood. I am really glad that on this list we can discuss subjects that are outside but... in a long term.. this list is devoted to technical things. I myself see no ground how I could fight here on a different subject than technical, especialy with my not so great Canadian English. zb. > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Sat Aug 3 19:32:46 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Sat, 03 Aug 2013 15:32:46 -0400 Subject: understanding probability[was Re: war story: parallel(1) command] In-Reply-To: <51FD5A30.5020409-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <30270_1375460888_r72GS7qn031201_alpine.NEB.2.00.1308021153360.12729@vex.net> <51FC0BA6.3020103@utoronto.ca> <51FD45AE.3010306@gmail.com> <51FD5435.4040501@rogers.com> <51FD5A30.5020409@gmail.com> Message-ID: <51FD5ADE.4030904@rogers.com> Zbigniew Koziol wrote: > I am really glad that on this list we can discuss subjects that are > outside but... in a long term.. this list is devoted to technical > things. I myself see no ground how I could fight here on a different > subject than technical, especialy with my not so great Canadian English. OK, I'll leave the Leafs out of it. ;-) -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Sat Aug 3 23:34:20 2013 From: colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Colin McGregor) Date: Sat, 3 Aug 2013 19:34:20 -0400 Subject: Raspberry PI Power In-Reply-To: <51FC21E1.5060608-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> References: <51FBD806.2010905@ss.org> <51FBEB54.9040109@gmail.com> <51FC21E1.5060608@gmail.com> Message-ID: On Fri, Aug 2, 2013 at 5:17 PM, Mike Kallies wrote: > On 02/08/2013 4:26 PM, Scott Allen wrote: > ... >> Again, like ripple, this is something that you would need an >> oscilloscope (or some other high bandwidth voltage min/max detector) >> to see. A standard voltmeter wouldn't show it. > > There was a really great article about this a while back: > > http://www.righto.com/2012/10/a-dozen-usb-chargers-in-lab-apple-is.html > > Detailed graphs of the power/voltage and overload characteristics of a > breadth of chargers. This is interesting. I went back through my USB power supplies, and it turns out I have an Apple A1357 (apparently a real one). The Apple A1357 is supposed to put out 2.1 amps @ 5.1 volts, but when I tested thing again with that power supply, the result was the same (could not get a usable WiFi connection). So, it seems that the Raspberry PI just can not support the power demands of the Ourlink WiFi dongle and a Logitech Unifying receiver... Disappointing... I do appreciate the comments though... Colin. > -Mike > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From mlxxxp-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Sun Aug 4 00:48:00 2013 From: mlxxxp-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Scott Allen) Date: Sat, 3 Aug 2013 20:48:00 -0400 Subject: Raspberry PI Power In-Reply-To: References: <51FBD806.2010905@ss.org> <51FBEB54.9040109@gmail.com> <51FC21E1.5060608@gmail.com> Message-ID: On 3 August 2013 19:34, Colin McGregor wrote: > So, it seems that the Raspberry PI just > can not support the power demands of the Ourlink WiFi dongle and a > Logitech Unifying receiver... Disappointing... What frequencies do the two devices use? Wireless keyboards and mice generally use the 2.4Ghz band. WiFi commonly uses the same, or 5Ghz. Is it possible that it's not a power problem at all, but that the two transceivers are on the same band and are in such close proximity that they are interfering with each other? If so, is it possible to put one on a USB extender cable to separate them, to see if it helps? -- Scott -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org Sun Aug 4 00:54:32 2013 From: kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org (Kevin Cozens) Date: Sat, 03 Aug 2013 20:54:32 -0400 Subject: Raspberry PI Power In-Reply-To: References: <51FBD806.2010905@ss.org> <51FBEB54.9040109@gmail.com> <51FC21E1.5060608@gmail.com> Message-ID: <51FDA648.8030403@ve3syb.ca> On 13-08-03 07:34 PM, Colin McGregor wrote: > it seems that the Raspberry PI just can not support the power demands of > the Ourlink WiFi dongle and a Logitech Unifying receiver... > Disappointing... I previously mentioned I have the OurLink WiFi device working with a Pi Model B with 512Meg and a 1 amp power supply. If you have an earlier Pi that has fuses on board *maybe* you are seeing a power supply issue. Before you blame the power supply, check to see if the router is seeing a connection from the Pi. Perhaps the problem is similar to what I experienced where the Pi was seen by my router but the Pi never received its IP address. As a test, try the Pi with a different router. IIRC, you said you didn't want to spend any additional money to get it going but it would be worth trying to see if you have a power problem, or a router related problem (as I did). -- Cheers! Kevin. http://www.ve3syb.ca/ |"Nerds make the shiny things that distract Owner of Elecraft K2 #2172 | the mouth-breathers, and that's why we're | powerful!" #include | --Chris Hardwick -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org Sun Aug 4 00:59:07 2013 From: kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org (Kevin Cozens) Date: Sat, 03 Aug 2013 20:59:07 -0400 Subject: [TLUG-ANNOUNCE]: Linux in the Park 2013 In-Reply-To: References: Message-ID: <51FDA75B.6010501@ve3syb.ca> On 13-08-03 06:44 PM, Colin McGregor wrote: > What : An informal get together for Linux geeks, freaks and friends > > When : August 17th, 2013 from 10:00 AM on. I would have given some thought to attending if you had picked a better weekend. August 17th is the first Saturday of the Ex which means it is Warriors Day so I will be at the CNE all day. The one good thing is that I have rarely seen it rain on Warriors Day (in the morning during the parade), so the chances are good that you will have good weather for an event in the park. -- Cheers! Kevin. http://www.ve3syb.ca/ |"Nerds make the shiny things that distract Owner of Elecraft K2 #2172 | the mouth-breathers, and that's why we're | powerful!" #include | --Chris Hardwick -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Sun Aug 4 01:36:22 2013 From: colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Colin McGregor) Date: Sat, 3 Aug 2013 21:36:22 -0400 Subject: [TLUG-ANNOUNCE]: Linux in the Park 2013 In-Reply-To: <51FDA75B.6010501-4dS5u2o1hCn3fQ9qLvQP4Q@public.gmane.org> References: <51FDA75B.6010501@ve3syb.ca> Message-ID: On Sat, Aug 3, 2013 at 8:59 PM, Kevin Cozens wrote: > On 13-08-03 06:44 PM, Colin McGregor wrote: >> >> What : An informal get together for Linux geeks, freaks and friends >> >> When : August 17th, 2013 from 10:00 AM on. > > I would have given some thought to attending if you had picked a better > weekend. August 17th is the first Saturday of the Ex which means it is > Warriors Day so I will be at the CNE all day. The classic problem, there is no such thing as an ideal date. Enjoy your day at the CNE and I hope we will see you at next year's Linux in the Park. > The one good thing is that I have rarely seen it rain on Warriors Day (in > the morning during the parade), so the chances are good that you will have > good weather for an event in the park. > > -- > Cheers! > > Kevin. > > http://www.ve3syb.ca/ |"Nerds make the shiny things that distract > Owner of Elecraft K2 #2172 | the mouth-breathers, and that's why we're > | powerful!" > #include | --Chris Hardwick Colin McGregor - VE3ZAA -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From sciguy-Ja3L+HSX0kI at public.gmane.org Sun Aug 4 14:26:05 2013 From: sciguy-Ja3L+HSX0kI at public.gmane.org (sciguy) Date: Sun, 04 Aug 2013 10:26:05 -0400 Subject: Partially dead drive Message-ID: I have a 1TB Seagate drive which, I admit, was partitioned when the NT drive was less than half full, and I didn't defrag the data to the start of the drive. It lasted a couple of months that way, then it all but bricked my computer. While the NT (W7) system partition was on a separate drive, GRUB was the MBR of the bad drive. The partitioning on the bad drive was done to install Linux. The NT partition on the bad drive was used for various data (no programs or system files) which I wanted to at least make a valiant attempt at trying to recover. All of the linux partitions seemed to have survived somehow, but when mounting the NTFS partition, I get an I/O error, even when booting with parted magic (live mode). I can use fdisk only if I invoke it when the bad drive is external and just turned on (in other words, no attempts to mount /dev/sdl1, the NTFS device in question, before that). When fdisk is used, I see what seems to be a complete partition table, along with secondary partitions, and the NTFS being on the first partition. I was reluctant to change anything until I did something less potentially destructive first. So, I tried the mount command in a shell. "mount /dev/sda1 sda1" caused Parted Magic to recognize it as an NT partition, but then report an I/O error, and recommended "chkdsk/f" in Windows. I booted into XP with the bad disk as an external drive, it mounted as drive letter P:, filesystem "RAW". Attempting chkdsk /f in a DOS shell resulted in my being told that chkdsk doesn't work for RAW filesystems. The data in the NTFS partition is worth some trouble in trying to at least partially recover data. Is there anything anyone might suggest that I haven't tried? Paul King -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Sun Aug 4 15:29:25 2013 From: colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Colin McGregor) Date: Sun, 4 Aug 2013 11:29:25 -0400 Subject: Raspberry PI Power In-Reply-To: References: <51FBD806.2010905@ss.org> <51FBEB54.9040109@gmail.com> <51FC21E1.5060608@gmail.com> Message-ID: On Sat, Aug 3, 2013 at 8:48 PM, Scott Allen wrote: > On 3 August 2013 19:34, Colin McGregor wrote: >> So, it seems that the Raspberry PI just >> can not support the power demands of the Ourlink WiFi dongle and a >> Logitech Unifying receiver... Disappointing... > > What frequencies do the two devices use? Wireless keyboards and mice > generally use the 2.4Ghz band. WiFi commonly uses the same, or 5Ghz. > > Is it possible that it's not a power problem at all, but that the two > transceivers are on the same band and are in such close proximity that > they are interfering with each other? If so, is it possible to put one > on a USB extender cable to separate them, to see if it helps? Good point, and one that I could check without spending $ (I had a roughly 1meter / 3 foot USB extension cable in my parts bin). So, I've tried the USB dongle at the end of the USB extension cable and the Apple A1357 power supply. Result was the same... :-( . > -- > Scott > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From opengeometry-FFYn/CNdgSA at public.gmane.org Sun Aug 4 16:17:29 2013 From: opengeometry-FFYn/CNdgSA at public.gmane.org (William Park) Date: Sun, 4 Aug 2013 12:17:29 -0400 Subject: Partially dead drive In-Reply-To: References: Message-ID: <20130804161729.GA31153@node1.localdomain> Usually, I would 'dd' and work on the copy using KVM (ie. qemu). But, if you're already getting IO errors, then 'dd'ing may brick it for real. On the other hand, you know it's going bad, so you may have no choice. Being NTFS, your options are Windows-limited. I used AOMEI Partition Assistant http://www.aomeitech.com/aomei-partition-assistant.html to resize NTFS partition on my XP laptop. It has other capabilities, so you may want to try that. -- William On Sun, Aug 04, 2013 at 10:26:05AM -0400, sciguy wrote: > I have a 1TB Seagate drive which, I admit, was partitioned when the > NT drive was less than half full, and I didn't defrag the data to > the start of the drive. It lasted a couple of months that way, then > it all but bricked my computer. While the NT (W7) system partition > was on a separate drive, GRUB was the MBR of the bad drive. The > partitioning on the bad drive was done to install Linux. The NT > partition on the bad drive was used for various data (no programs or > system files) which I wanted to at least make a valiant attempt at > trying to recover. > > All of the linux partitions seemed to have survived somehow, but > when mounting the NTFS partition, I get an I/O error, even when > booting with parted magic (live mode). > > I can use fdisk only if I invoke it when the bad drive is external > and just turned on (in other words, no attempts to mount /dev/sdl1, > the NTFS device in question, before that). When fdisk is used, I see > what seems to be a complete partition table, along with secondary > partitions, and the NTFS being on the first partition. I was > reluctant to change anything until I did something less potentially > destructive first. > > So, I tried the mount command in a shell. "mount /dev/sda1 sda1" > caused Parted Magic to recognize it as an NT partition, but then > report an I/O error, and recommended "chkdsk/f" in Windows. > > I booted into XP with the bad disk as an external drive, it mounted > as drive letter P:, filesystem "RAW". Attempting chkdsk /f in a DOS > shell resulted in my being told that chkdsk doesn't work for RAW > filesystems. > > The data in the NTFS partition is worth some trouble in trying to at > least partially recover data. Is there anything anyone might suggest > that I haven't tried? > > Paul King > > > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From opengeometry-FFYn/CNdgSA at public.gmane.org Sun Aug 4 16:18:32 2013 From: opengeometry-FFYn/CNdgSA at public.gmane.org (William Park) Date: Sun, 4 Aug 2013 12:18:32 -0400 Subject: understanding probability[was Re: war story: parallel(1) command] In-Reply-To: <51FD45AE.3010306-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> References: <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <30270_1375460888_r72GS7qn031201_alpine.NEB.2.00.1308021153360.12729@vex.net> <51FC0BA6.3020103@utoronto.ca> <51FD45AE.3010306@gmail.com> Message-ID: <20130804161832.GA31431@node1.localdomain> On Sat, Aug 03, 2013 at 10:02:22PM +0400, Zbigniew Koziol wrote: > How many atoms are in the Universe? > 10^78 to 10^82 Prove it. -- William -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Sun Aug 4 17:36:58 2013 From: colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Colin McGregor) Date: Sun, 4 Aug 2013 13:36:58 -0400 Subject: Open Street Map and GTALug. Message-ID: As noted on our announce list GTALug will be having a picnic in Dufferin Grove park August 17th and in with the announcement was a link to the Open Street Map view of the park (it would be ... silly ... to have a picnic celebrating open source with a link to a proprietary map). So, there were some serious issues with the Dufferin Grove park map. Saturday morning I walked around the park for about 45 minutes with a hand held GPS to collect path tracks and note some of the features of the park. I've been entering what I saw into Open Street Map, so the map is now a lot better, but... There is still a LOT of room for improvement, so, I would really appreciate it if people who really know Open Street Map and/or Dufferin Grove Park could further improve the map: http://www.openstreetmap.org/?lat=43.65651&lon=-79.43537&zoom=16&layers=M Thanks. Colin McGregor -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Sun Aug 4 18:00:20 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Sun, 04 Aug 2013 14:00:20 -0400 Subject: understanding probability[was Re: war story: parallel(1) command] In-Reply-To: <20130804161832.GA31431-+21/tKCbORjP0Z7Jsv878P8+0UxHXcjY@public.gmane.org> References: <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <30270_1375460888_r72GS7qn031201_alpine.NEB.2.00.1308021153360.12729@vex.net> <51FC0BA6.3020103@utoronto.ca> <51FD45AE.3010306@gmail.com> <20130804161832.GA31431@node1.localdomain> Message-ID: <51FE96B4.4070105@rogers.com> William Park wrote: >> How many atoms are in the Universe? >> > 10^78 to 10^82 > Prove it. Lessee now, one, two, three and another and... ;-) -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Sun Aug 4 18:26:21 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Sun, 4 Aug 2013 14:26:21 -0400 (EDT) Subject: Partially dead drive In-Reply-To: References: Message-ID: | From: sciguy | To: tlug-lxSQFCZeNF4 at public.gmane.org | Date: Sun, 04 Aug 2013 10:26:05 -0400 | Subject: [TLUG]: Partially dead drive | Reply-To: tlug-lxSQFCZeNF4 at public.gmane.org | | I have a 1TB Seagate drive which, I admit, was partitioned when the NT drive | was less than half full, and I didn't defrag the data to the start of the | drive. Why do you have to "admit" that? Are there any consequences? When I've used Linux tools to resize a Windows boot partition, I've found it important to immediately boot Windows and do a repair. This is before installing Linux. I think that the resizing might be moving unmoveable files and the Windows repair tools can fix that. Windows (without 3rd party tools) can resize its own partitions but it seems to not wish to move any unmoveable files (like perhaps SWAP) and so it cannot shrink as much as one would like. Getting rid of the swap file (somewhere in settings) temporarily might help | It lasted a couple of months that way, then it all but bricked my | computer. While the NT (W7) system partition was on a separate drive, GRUB was | the MBR of the bad drive. The partitioning on the bad drive was done to | install Linux. The NT partition on the bad drive was used for various data (no | programs or system files) which I wanted to at least make a valiant attempt at | trying to recover. So: you are saying that the problem is raw disk I/O errors. Nothing to do with partitioning. But symptoms and recovery methods involve partitions and file systems. Right? | All of the linux partitions seemed to have survived somehow, but when mounting | the NTFS partition, I get an I/O error, even when booting with parted magic | (live mode). Disks often go bad in a number of spots. Often, an increasing number of spots. The bullet holes in a filesystem don't always hit vital organs. If you care, the very FIRST thing you should do when you have trouble like this, and you care at all about your data, is capture an image of the disk (or perhaps images of partitions) onto somewhere safe. Why? - disks have a way of getting worse. - (superstition) sequential reads of a disk might be more successful than random access reads - fsck and friends may make things worse. Just one way: terminating half-way through - you, the human, can easily make fatal mistakes in the heat of battle. The best tool I know (which isn't saying much) for capturing the image is GNU DD Rescue (confusingly there are three different programs called ddrescue). There's a lot to like about ddrescue but the documentation isn't that comforting to a panicking user. Hints: - always invoke it with a logfile parameter. That's where it keeps track of what's done, what's failed, what's untried, etc. - the first time you run it, don't ask it to retry. - When it's done the first run, you can run it again (with the same logfile!) and ask it to retry. I found that the retrying eked out a little more from the disk, but very slowly. | The data in the NTFS partition is worth some trouble in trying to at least | partially recover data. Is there anything anyone might suggest that I haven't | tried? smartmontools are useful. They let you get at the S.M.A.R.T. capability of the drive. Mind you, most external USB cases fail to support S.M.A.R.T. smartctl -a /dev/whatever tells you lots of stuff. Unfortunately, most firmware tries to make reports optimistic in several ways. smartctl -t short /dev/whatever starts an offline short self-test. When the time is up, you need to do a smartctl -a to see the result. The long test is useful too, but long. When disks fail partially, it matters where the bullet holes end up: metadata (think partition table, inodes, directories) or data or even unused space. fsck and chkdisk (is that actually what it is called these days?) fix metadata. There are tools (that I don't remember and haven't needed) that grovel through the raw bits of a disk and try to find things that seem like JPEG files. Being undermotivated, I will suggest googling. But here's a long article that might be helpful (I've only glanced at it): -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From bjonkman-w5ExpX8uLjYAvxtiuMwx3w at public.gmane.org Sun Aug 4 20:02:33 2013 From: bjonkman-w5ExpX8uLjYAvxtiuMwx3w at public.gmane.org (Bob Jonkman) Date: Sun, 04 Aug 2013 16:02:33 -0400 Subject: Open Street Map and GTALug. Message-ID: Sounds like the picnic could be an opportunity for a mapping party. Sadly I am unable to be there... But could you put an entry in the GTALUG calendar too? --Bob. Colin McGregor wrote: >As noted on our announce list GTALug will be having a picnic in >Dufferin Grove park August 17th and in with the announcement was a >link to the Open Street Map view of the park (it would be ... silly >... to have a picnic celebrating open source with a link to a >proprietary map). > >So, there were some serious issues with the Dufferin Grove park map. >Saturday morning I walked around the park for about 45 minutes with a >hand held GPS to collect path tracks and note some of the features of >the park. I've been entering what I saw into Open Street Map, so the >map is now a lot better, but... > >There is still a LOT of room for improvement, so, I would really >appreciate it if people who really know Open Street Map and/or >Dufferin Grove Park could further improve the map: >http://www.openstreetmap.org/?lat=43.65651&lon=-79.43537&zoom=16&layers=M > >Thanks. > > >Colin McGregor >-- >The Toronto Linux Users Group. Meetings: http://gtalug.org/ >TLUG requests: Linux topics, No HTML, wrap text below 80 columns >How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From sciguy-Ja3L+HSX0kI at public.gmane.org Sun Aug 4 20:06:00 2013 From: sciguy-Ja3L+HSX0kI at public.gmane.org (Paul King) Date: Sun, 4 Aug 2013 16:06:00 -0400 Subject: Partially dead drive In-Reply-To: References: Message-ID: <000001ce914e$0a85a390$1f90eab0$@net> Hugh: || I have a 1TB Seagate drive which, I admit, was partitioned when the NT || drive was less than half full, and I didn't defrag the data to the || start of the drive. | Why do you have to "admit" that? Are there any consequences? I felt I needed to mention that because I may have set a partition boundary during resizing in a way that closed off a file or cut it off. I could be wrong. While I normally back up my data, and my most critical data for work is available in several copies on lots of storage media, my personal stuff -- email, stuff downloaded from Emusic or Itunes, hadn't been treated as nicely as that. I am sure prospects for recovery are dim, but I'll give it a try before tossing it. FWIW, EMusic no longer allowed me to re-download all of my purchased music (they used to). They have now resorted to handing me a courtesy credit of $60, which does not account for even a fourth of the purchases I made. I haggled it to $80. I am less worried about ITunes, for which I mostly downloaded free audio and video from ITunesU. I would also like to recover what email I can. | When I've used Linux tools to resize a Windows | boot partition, I've found it important to immediately boot Windows | and do a repair. This is before installing Linux. I think that | the resizing might be moving unmoveable files and the Windows | repair tools can fix that. The hard drive in question was for data. It wasn't a system drive. || It lasted a couple of months that way, then it all but bricked my || computer. While the NT (W7) system partition was on a separate drive, || GRUB was the MBR of the bad drive. The partitioning on the bad drive || was done to install Linux. The NT partition on the bad drive was used || for various data (no programs or system files) which I wanted to at || least make a valiant attempt at trying to recover. | So: you are saying that the problem is raw disk I/O errors. | Nothing to do with partitioning. But symptoms and recovery methods | involve partitions and file systems. Right? I am only telling you what errors I saw. I wasn't attempting to make interpretations. But yes, most partitions lived, and mounting NTFS gives me I/O errors. | Disks often go bad in a number of spots. Often, an increasing number | of spots. The bullet holes in a filesystem don't always hit vital | organs. | If you care, the very FIRST thing you should do when you have trouble | like this, and you care at all about your data, is capture an image | of the disk (or perhaps images of partitions) onto somewhere safe. The errors happened suddenly. It was simply that, one day, I could not reboot the machine. And this was because Grub was on the failed drive. But since I suspected that reducing a partition size and creating new partitions was going to "do something" unstable, I probably should have made a backup before doing that. Thanks for your valuable advice, Hugh. This can prove helpful, although things are looking pretty dim at this point. Paul King -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Sun Aug 4 20:59:22 2013 From: colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Colin McGregor) Date: Sun, 4 Aug 2013 16:59:22 -0400 Subject: Open Street Map and GTALug. In-Reply-To: References: Message-ID: On Sun, Aug 4, 2013 at 4:02 PM, Bob Jonkman wrote: > Sounds like the picnic could be an opportunity for a mapping party. Sadly I am unable to be there... A potentially good thought. > But could you put an entry in the GTALUG calendar too? Now done. > --Bob. > > Colin McGregor wrote: > >>As noted on our announce list GTALug will be having a picnic in >>Dufferin Grove park August 17th and in with the announcement was a >>link to the Open Street Map view of the park (it would be ... silly >>... to have a picnic celebrating open source with a link to a >>proprietary map). >> >>So, there were some serious issues with the Dufferin Grove park map. >>Saturday morning I walked around the park for about 45 minutes with a >>hand held GPS to collect path tracks and note some of the features of >>the park. I've been entering what I saw into Open Street Map, so the >>map is now a lot better, but... >> >>There is still a LOT of room for improvement, so, I would really >>appreciate it if people who really know Open Street Map and/or >>Dufferin Grove Park could further improve the map: >>http://www.openstreetmap.org/?lat=43.65651&lon=-79.43537&zoom=16&layers=M >> >>Thanks. >> >> >>Colin McGregor >>-- >>The Toronto Linux Users Group. Meetings: http://gtalug.org/ >>TLUG requests: Linux topics, No HTML, wrap text below 80 columns >>How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Mon Aug 5 01:15:38 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Sun, 4 Aug 2013 21:15:38 -0400 (EDT) Subject: Partially dead drive In-Reply-To: <000001ce914e$0a85a390$1f90eab0$@net> References: <000001ce914e$0a85a390$1f90eab0$@net> Message-ID: | From: Paul King | || I have a 1TB Seagate drive which, I admit, was partitioned when the NT | || drive was less than half full, and I didn't defrag the data to the | || start of the drive. | | | Why do you have to "admit" that? Are there any consequences? | | I felt I needed to mention that because I may have set a partition boundary | during resizing in a way that closed off a file or cut it off. I could be | wrong. How did you resize? I hope it wasn't just fdisking to set another boundary. Programs meant to do resizing must understand the filesystem in question and manipulate it to allow resizing. gparted does this, for example. Partition Magic was the first popular commercial tool to do this. The task is tricky enough that PM was considered, umm, magical when it first came out. If you used a suitable tool, you would not have cut off a file. Unless it was buggy: then all bets are off. | FWIW, EMusic no longer allowed me to re-download all of my purchased music | (they used to). Wow. But on the other hand, it wasn't DRMed, if I remember correctly. What I really hate is a DRMed platform disappearing (eg. MS Plays For Sure -- what an inappropriate title!). I always thought that an argument for the cloud was that they were safer than leaving things in your own hands. | | When I've used Linux tools to resize a Windows | | boot partition, I've found it important to immediately boot Windows | | and do a repair. This is before installing Linux. I think that | | the resizing might be moving unmoveable files and the Windows | | repair tools can fix that. | | The hard drive in question was for data. It wasn't a system drive. | It might still have unmoveable files -- I don't know enough about Windows to say for sure. Hmm... At one time suspend-to-disk was managed by the BIOS and it had to know where to write stuff. It wrote to the Windows swap file (or a special partition). If the swapfile was moved or deleted, the BIOS needed to be "told". I *think* that this mechanism disappeared with APM. Not sure. | The errors happened suddenly. It was simply that, one day, I could not | reboot the machine. And this was because Grub was on the failed drive. | | No, not doing backups, doing recovery carefully. It's not too late! Take an image! I know that it is pointless to ask someone to get in their time machine and do a backup in the past. | But since I suspected that reducing a partition size and creating new | partitions was going to "do something" unstable, I probably should have | made a backup before doing that. I often takes my chances. Only once was that a problem. Vista became unbootable. So I had to buy restore CDs from Acer (the machine had a 1 year warranty but apparently installation problems were only covered for 90 days). Later I learned that the bundled a Window upgrade disk could do the repairs (thanks, Lennart!). | Thanks for your valuable advice, Hugh. This can prove helpful, although | things are looking pretty dim at this point. Have you tried any of the advice? To re-iterate: - start by grabbing an image using GNU ddrescue. - For a Linux filesystem, you can loopback mount an image file and hack on that. - For ntfs, I'd recommend plopping the image, raw, as the contents of a partition and whacking on it in the new place. The new partition doesn't have to be exactly the same size as the original: it can be larger. - I pointed at an article which talked about programs that can root through a busted filesystem for valuables. - I also mentioned Smartmon Tools to know disk hardware status. - I forgot to mention the the output of dmesg might give some clues about I/O errors. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From sciguy-Ja3L+HSX0kI at public.gmane.org Mon Aug 5 03:24:06 2013 From: sciguy-Ja3L+HSX0kI at public.gmane.org (Paul King) Date: Sun, 4 Aug 2013 23:24:06 -0400 Subject: Partially dead drive In-Reply-To: References: <000001ce914e$0a85a390$1f90eab0$@net> Message-ID: <000301ce918b$3e9de560$bbd9b020$@net> || I felt I needed to mention that because I may have set a partition || boundary during resizing in a way that closed off a file or cut it || off. I could be wrong. | | How did you resize? I hope it wasn't just fdisking to set another boundary. I resized using the native tools that came with the Mint install, and later Ubuntu Studio install (which does not use Unity). The triple boot trick worked up until the next kernel update of Ubuntu Studio, when a manual rewrite of the grub menu became necessary (Mint was not detected). I never got around to it, being too busy with work. Both linuxes used the same /home, /tmp, swap and /boot partitions. For a while I thought it was a pretty neat experiment, both are Debian-based, and both seemed to get along. This was done about 4 months ago, and Ubuntu menu issue over a month ago, and the NTFS failure was in the past 2 weeks. The only consequence I could see for the menu issue was that I couldn't boot into Mint. So, being busy with other things, I didn't consider it life-threatening enough to fix. | Programs meant to do resizing must understand the filesystem in question | and manipulate it to allow resizing. gparted does this, for example. | Partition Magic was the first popular commercial tool to do this. The task | is tricky enough that PM was considered, umm, magical when it first came out. Well, hopefully that means that the weird partitioning I did, using well-used Linux tools, didn't cause the problem. Hopefully. | If you used a suitable tool, you would not have cut off a file. | Unless it was buggy: then all bets are off. Well, I didn't use anything non-standard, and nothing like FDISK. All the tools I used, IIRC, were graphical, such as gparted, and were part of the installation. || FWIW, EMusic no longer allowed me to re-download all of my purchased || music (they used to). | Wow. But on the other hand, it wasn't DRMed, if I remember correctly. | What I really hate is a DRMed platform disappearing (eg. MS Plays For Sure | -- what an inappropriate title!). Emusic deals with mp3 formats, which as I understand it, is not DRM'ed. I have copied selected mp3's to other media without incident. | I always thought that an argument for the cloud was that they were | safer than leaving things in your own hands. ... all grist for a different thread ... But if I could find a link I would refer you to an online discussion about a fellow from a health care company who was in a panic because a "fail-safe" server "in the cloud" failed along with its backup server, placing some housebound patients under varying degrees of critical care in jeopardy. In the thread, a question was asked by someone who probably had no healthcare experience but sufficient tech savvy: "Whose crazy idea was it to trust 'cloud' servers with the handling of life-critical health data?" This was followed by remark that would logically follow: "Fire that person and start getting used to making house visits!" | Have you tried any of the advice? To re-iterate: I fully intend to try it out. I will be at a conference in Barrie most of this week, but I will see what I can do. I have some time between tonight and Monday. I will let you know how it goes. Paul King -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From antoniosun-N9AOi2cAC9ZBDgjK7y7TUQ at public.gmane.org Mon Aug 5 16:20:21 2013 From: antoniosun-N9AOi2cAC9ZBDgjK7y7TUQ at public.gmane.org (Antonio Sun) Date: Mon, 5 Aug 2013 12:20:21 -0400 Subject: Input on future mobile platform Message-ID: Hi, What's your idea about the near future mobile platform? What's in trending? Which of today's technology do you think will take the lead tomorrow? I'm mainly talking about the technology driven world (i.e., the Android world) because I view Apple's iSeries more of company driven, because in my view, the Android world is more open to the new technologies. E.g., you can put Ubuntu on Android devices now. The reason that I'm asking is that, although the Java-based Android is in domain of current mobile development platform (in my so-called technology driven world of course), I don't think it will be future, and I don't believe Google is happy about the Java-based platform either. What do you think? Which one will win over tomorrow? I have my own view on this, but would like to know yours as well. Thanks Antonio -------------- next part -------------- An HTML attachment was scrubbed... URL: From william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Mon Aug 5 19:34:35 2013 From: william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (William Muriithi) Date: Mon, 5 Aug 2013 15:34:35 -0400 Subject: Input on future mobile platform In-Reply-To: References: Message-ID: wrote: > > Hi, > > What's your idea about the near future mobile platform? What's in trending? Which of today's technology do you think will take the lead tomorrow? > Ha, this is something you are not going to get a shared agreement, just a bit of fights. That being said, nothing is changing soon, android will keep entrenching itself in the market due to being cheap. I think most of the developing world will all hop into android world. The IOS will retain a good share especially in developed world. Windows on phone may not be happening, just look at their recent SEC filing. In short, status quo. > I'm mainly talking about the technology driven world (i.e., the Android world) because I view Apple's iSeries more of company driven, because in my view, the Android world is more open to the new technologies. E.g., you can put Ubuntu on Android devices now. > Android is not open according to some people. They do share their code, but only after the product has been in market for a while. > The reason that I'm asking is that, although the Java-based Android is in domain of current mobile development platform (in my so-called technology driven world of course), I don't think it will be future, and I don't believe Google is happy about the Java-based platform either. What do you think? Which one will win over tomorrow? > What make you think Google is not happy about it? Never seen any article that imply the hate Java, they actually used it a lot even before android > I have my own view on this, but would like to know yours as well. > Hmm, weird. So what if everybody adopt similar strategy? > Thanks > > Antonio > -------------- next part -------------- An HTML attachment was scrubbed... URL: From cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Mon Aug 5 23:35:07 2013 From: cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Christopher Browne) Date: Mon, 5 Aug 2013 19:35:07 -0400 Subject: Input on future mobile platform In-Reply-To: References: Message-ID: I think there's not likely to be anyone that has a coherent idea as to what The Next Thing will be. Further, the notion that it's Mostly About The Technology seems laughable, because the customers that *buy* millions of mobile devices aren't about the technology. The *major* customers that will be determining what sorts of functionalities are important in the next "remake" of the mobile phone are, like, - China Mobile - Vodaphone - Airtel - SingTel - Telefonica - Orange - America Movil that is, the operators of mobile phone networks, who are the ones that purchase all but some statistically insignificant number of mobile phones. They're not particularly concerned about Java, or how much memory iOS saves over Android. Apple significantly disrupted their market, when they demonstrated that the mobile carriers could make *more* money by selling expensive iPhones, and giving up on the (expensive-to-manage) per-carrier application stores. Android showed that this wasn't just a flash in the pan, but rather that it was a repeatable phenomenon. It is in the interests of the customers buying mobile phones for there to be competition between mobile phone manufacturers, for which reason Windows Mobile and Blackberry haven't been dropped; it's valuable to have options in the wings so that the carriers can, if provoked, bring them out as alternatives to iOS/Android. At some point, iOS and Android will presumably suffer from the same problem that various past vendors have had; the code is eventually old and somewhat crufty, and, more crucially, not flexible to cope with some disruption that will take place five or ten years from now. Symbian "died" because of that, as did PalmOS. RIM seems to be in that phase; it will be curious to see if they survive, because a small niche isn't enough. But since it is quite likely that, ten years from now, the set of customers, namely China Mobile, Vodaphone, et al, will only have had minor demographic changes, the needs that mandate picking a new phone will likely still center around their needs in servicing their markets. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Tue Aug 6 00:17:41 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Mon, 5 Aug 2013 20:17:41 -0400 (EDT) Subject: Partially dead drive In-Reply-To: <000301ce918b$3e9de560$bbd9b020$@net> References: <000001ce914e$0a85a390$1f90eab0$@net> <000301ce918b$3e9de560$bbd9b020$@net> Message-ID: | From: Paul King | I resized using the native tools that came with the Mint install, and later | Ubuntu Studio install (which does not use Unity). Good. That ought to be safe. | The triple boot trick | worked up until the next kernel update of Ubuntu Studio, when a manual | rewrite of the grub menu became necessary (Mint was not detected). I never | got around to it, being too busy with work. It might be this bug The fix is known but an update to Ubuntu 12.04 has not been released. This is an example of what makes me unhappy with Ubuntu (see others complaining in that report). The bug status became "Fix Released" last Christmas Eve Eve. The workaround for me is: - mount the Fedora / partition - sudo update-grub | Both linuxes used the same | /home, | /tmp, swap and /boot partitions. For a while I thought it was a pretty neat | | experiment, both are Debian-based, and both seemed to get along. This was | done | about 4 months ago, and Ubuntu menu issue over a month ago, I don't know what shared /boot does as far as os-prober is concerned. Since your bug showed up some time after 4 months ago, it might not be 1038093. | and the NTFS | failure was in the past 2 weeks. Probably unrelated. But it means you cannot try Mint to see if it likes the NTFS volume better. (I don't expect a surprising result.) | | Have you tried any of the advice? To re-iterate: | | I fully intend to try it out. Good luck! I was just concerned that you read my whole message as "you should have backed up your files". -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Tue Aug 6 01:37:12 2013 From: william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (William Muriithi) Date: Mon, 5 Aug 2013 21:37:12 -0400 Subject: Input on future mobile platform In-Reply-To: References: Message-ID: > I think there's not likely to be anyone that has a coherent idea as to > what The Next Thing will be. > > Further, the notion that it's Mostly About The Technology seems > laughable, because the customers that *buy* millions of mobile devices > aren't about the technology. > Totally agree with you. Smartphone is a mature technology. All those who care about the interface, technology or features has taken a side already . The rest will mainly be driven by only one attribute and one attribute alone, how much will it cost them. So if windows can undercut the competition, their future is great. William > The *major* customers that will be determining what sorts of > functionalities are important in the next "remake" of the mobile phone > are, like, > - China Mobile > - Vodaphone > - Airtel > - SingTel > - Telefonica > - Orange > - America Movil > that is, the operators of mobile phone networks, who are the ones that > purchase all but some statistically insignificant number of mobile > phones. > > They're not particularly concerned about Java, or how much memory iOS > saves over Android. > > Apple significantly disrupted their market, when they demonstrated > that the mobile carriers could make *more* money by selling expensive > iPhones, and giving up on the (expensive-to-manage) per-carrier > application stores. Android showed that this wasn't just a flash in > the pan, but rather that it was a repeatable phenomenon. > > It is in the interests of the customers buying mobile phones for there > to be competition between mobile phone manufacturers, for which reason > Windows Mobile and Blackberry haven't been dropped; it's valuable to > have options in the wings so that the carriers can, if provoked, bring > them out as alternatives to iOS/Android. > > At some point, iOS and Android will presumably suffer from the same > problem that various past vendors have had; the code is eventually old > and somewhat crufty, and, more crucially, not flexible to cope with > some disruption that will take place five or ten years from now. > Symbian "died" because of that, as did PalmOS. RIM seems to be in > that phase; it will be curious to see if they survive, because a small > niche isn't enough. > > But since it is quite likely that, ten years from now, the set of > customers, namely China Mobile, Vodaphone, et al, will only have had > minor demographic changes, the needs that mandate picking a new phone > will likely still center around their needs in servicing their > markets. > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -------------- next part -------------- An HTML attachment was scrubbed... URL: From evan-ieNeDk6JonTYtjvyW6yDsg at public.gmane.org Tue Aug 6 01:59:08 2013 From: evan-ieNeDk6JonTYtjvyW6yDsg at public.gmane.org (Evan Leibovitch) Date: Mon, 5 Aug 2013 21:59:08 -0400 Subject: Need some help with "upstart" Message-ID: Hi all. As an an ongoing part of developing a home media server, I am wrestling with the init-script replacement system in Ubuntu called "upstart". The server is running four services: - sabnzbdplus - sickbeard - plexmediaserver - deluged The first two run fine at bootup. The latter two will not automatically start on boot, but will happily start manually with "service start". I have no idea how to debug this. I've stared at the Upstart Cookbook ( http://upstart.ubuntu.com/cookbook/) for some time but it hasn't helped. Any suggestions are welcome. -- Evan Leibovitch Toronto Canada Em: evan at telly dot org Sk: evanleibovitch Tw: el56 -------------- next part -------------- An HTML attachment was scrubbed... URL: From northdot9-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Tue Aug 6 03:38:24 2013 From: northdot9-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (David Thornton) Date: Mon, 5 Aug 2013 23:38:24 -0400 Subject: Need some help with "upstart" In-Reply-To: References: Message-ID: 1. Try capturing $? 2. Try to capture the command's output in the startups script ( command > /tmp/my_out_file ) 3. Try to capture stderr ( command 2 > /tmp/my_error_file ) 4. Upstart might have command line options like --verbose. I recall there was a little learning curve with gentoo init scripts. Where before I was debugging bash inits scripts by adding -x to the script, in gentoo I had to add --verbose . Upstart must have some sort of mechanism for recording every step. David On 8/5/13, Evan Leibovitch wrote: > Hi all. > > As an an ongoing part of developing a home media server, I am wrestling > with the init-script replacement system in Ubuntu called "upstart". > > The server is running four services: > > - sabnzbdplus > - sickbeard > - plexmediaserver > - deluged > > > The first two run fine at bootup. The latter two will not automatically > start on boot, but will happily start manually with "service start". > > I have no idea how to debug this. I've stared at the Upstart Cookbook ( > http://upstart.ubuntu.com/cookbook/) for some time but it hasn't helped. > > Any suggestions are welcome. > > -- > Evan Leibovitch > Toronto Canada > > Em: evan at telly dot org > Sk: evanleibovitch > Tw: el56 > -- Sent from my mobile device -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From gyre-Ja3L+HSX0kI at public.gmane.org Tue Aug 6 06:52:26 2013 From: gyre-Ja3L+HSX0kI at public.gmane.org (Eric) Date: Tue, 6 Aug 2013 02:52:26 -0400 (EDT) Subject: understanding probability In-Reply-To: <51FD57D5.60000-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <51FD57D5.60000@rogers.com> Message-ID: On Sat, 3 Aug 2013, James Knott wrote: > However, my understanding about probabilities says that while something > may be unlikely, it's not impossible and, according to chance may even > happen immediately. That is the intuitive paradox. One could argue that anything that appears to be impossible is only very improbable, since given a few tweaks you can make the impossible into something extremely improbable. However, rational people shouldn't fret about impossible events. For example, according to radioactive statistics, it is possible that all the atoms in any non-supercritical fissile mass may spontaneous decay, all at once, since each atom has a finite probability of decaying in the next second. The total spontaneous decay probability is unimaginably small. No scientist is concerned with that because, although mathematically possible, it is practically impossible. In a finite observable universe, some things will never happen. And to make the odds even more improbable, the actual realm where we exist is a tiny tiny fraction of that observable universe. > The astrophysicist Brian Greene has some > interesting comments on this sort of thing, in the realm of infinite > universes. One thing he mentions is that if the universe is truly > infinite, then some subset of it, such as the portion within our > observable limits, must be repeated an infinite number of times. Yes, within the framework of theoretical infinities, everything will happen sometime; so what? That is pure speculation. That doesn't change the odds within the relatively small finite (not infinite) realm where we exist. (Green could be speculating to explain how the laws of physics appear to be fine-tuned.) > Another thing he mentioned was if you shuffle a deck of cards, while > highly unlikely, one possible outcome is all the cards will be properly > sorted. This is because no matter how many there are, there are a > finite number of possible combinations. Once you've shuffled past that > number of times, and likely well before it, then repeat sequences are > inevitable. In an ideal shuffle, every permutation is equally likely. There is nothing special about all the cards being properly sorted. It only seems remarkable because it is easy to recognize. Or as Feynman satirically pointed out: "You know, the most amazing thing happened to me tonight. I was coming here, on the way to the lecture, and I came in through the parking lot. And you won't believe what happened. I saw a car with the license plate ARW 357. Can you imagine? Of all the millions of license plates in the state, what was the chance that I would see that particular one tonight? Amazing!" The fallacy in the card deck premise is the phrase "once you've shuffled past that number of times". Since you will never reach that number (52!), it's a non-problem. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From richard-gNTHUr35LhcAvxtiuMwx3w at public.gmane.org Tue Aug 6 13:03:20 2013 From: richard-gNTHUr35LhcAvxtiuMwx3w at public.gmane.org (Richard Weait) Date: Tue, 6 Aug 2013 09:03:20 -0400 Subject: Ninth Birthday celebration, OpenStreetMap Message-ID: Hi Mappers. Y'all are mappers aren't you? If you've been hanging around on this list for a while, you've seen my posts relating to OpenStreetMap, and related events. You might have even caught one or more of my presentations on the topic at TLUG or neighbouring groups. It's hard for me to believe that the project is turning nine years old. That's something for a FLOSS project. That's really something for an OpenData project. If you have contributed to OpenStreetMap by surveying your neighbourhood, adding your favourite cafe, or writing code, etc. this even announcement is for you. We're having a birthday party for OpenStreetMap this Saturday. Come and join us for refreshments and conversation. The official information is on a proprietary meeting site, reach me by email if you prefer. http://www.meetup.com/OpenStreetMap-Toronto/events/123777892/ Your RSVP is required by Thursday night so that we can have enough 'vittles' for all you hungry mappers. In the interim, go on out and map something. The city, and your neighbourhood , have changed in the last nine years. Be sure to keep OpenStreetMap data right up to date. There will be a collective mapping adventure Saturday before the party. Join in on that as well, if you want a little mapping action to build up your hunger. See the details on the same web site. Best regards, Richard -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From bjonkman-w5ExpX8uLjYAvxtiuMwx3w at public.gmane.org Tue Aug 6 17:53:52 2013 From: bjonkman-w5ExpX8uLjYAvxtiuMwx3w at public.gmane.org (Bob Jonkman) Date: Tue, 06 Aug 2013 13:53:52 -0400 Subject: Compare-by-hash Message-ID: <52013830.8030609@sobac.com> Going back to a previous thread (which message-ID I have lost, and so the continuity of the thread; sorry for the disjoint reply) Joshua Rozen points[1] me to an article[2] on hash collisions by Valerie Henson of Sun Microsystems: > Recent[3] research has produced a new and perhaps dangerous technique > for uniquely identifying blocks that I will call compare-by-hash. > Using this technique, we decide whether two blocks are identical to > each other by comparing their hash values, using a > collision-resistant hash such as SHA-1. If the hash values match, > we assume the blocks are identical without further ado. Users of > compare-by-hash argue that this assumption is warranted because the > chance of a hash collision between any two randomly generated blocks > is estimated to be many orders of magnitude smaller than the chance > of many kinds of hardware errors. Further analysis shows that this > approach is not as risk-free as it seems at first glance. --Bob. [1] http://status.hackerposse.com/notice/51218 [2] http://valerieaurora.org/review/hash/node1.html [3] "Recent" relative to 2003, when the article was published -- Bob Jonkman http://sobac.com/sobac/ SOBAC Microcomputer Services Phone: +1-519-669-0388 6 James Street, Elmira ON Canada N3B 1L5 Cell: +1-519-635-9413 Software --- Office & Business Automation --- Consulting -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 263 bytes Desc: OpenPGP digital signature URL: From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Tue Aug 6 21:40:43 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Tue, 6 Aug 2013 17:40:43 -0400 Subject: Partially dead drive In-Reply-To: References: Message-ID: <20130806214043.GA14595@csclub.uwaterloo.ca> On Sun, Aug 04, 2013 at 10:26:05AM -0400, sciguy wrote: > I have a 1TB Seagate drive which, I admit, was partitioned when the > NT drive was less than half full, and I didn't defrag the data to > the start of the drive. It lasted a couple of months that way, then > it all but bricked my computer. While the NT (W7) system partition > was on a separate drive, GRUB was the MBR of the bad drive. The > partitioning on the bad drive was done to install Linux. The NT > partition on the bad drive was used for various data (no programs or > system files) which I wanted to at least make a valiant attempt at > trying to recover. > > All of the linux partitions seemed to have survived somehow, but > when mounting the NTFS partition, I get an I/O error, even when > booting with parted magic (live mode). > > I can use fdisk only if I invoke it when the bad drive is external > and just turned on (in other words, no attempts to mount /dev/sdl1, > the NTFS device in question, before that). When fdisk is used, I see > what seems to be a complete partition table, along with secondary > partitions, and the NTFS being on the first partition. I was > reluctant to change anything until I did something less potentially > destructive first. > > So, I tried the mount command in a shell. "mount /dev/sda1 sda1" > caused Parted Magic to recognize it as an NT partition, but then > report an I/O error, and recommended "chkdsk/f" in Windows. > > I booted into XP with the bad disk as an external drive, it mounted > as drive letter P:, filesystem "RAW". Attempting chkdsk /f in a DOS > shell resulted in my being told that chkdsk doesn't work for RAW > filesystems. > > The data in the NTFS partition is worth some trouble in trying to at > least partially recover data. Is there anything anyone might suggest > that I haven't tried? Did you resize the existing partition with parted or similar? Or did you just change the partition table? -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Wed Aug 7 15:11:00 2013 From: cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Christopher Browne) Date: Wed, 7 Aug 2013 11:11:00 -0400 Subject: understanding probability In-Reply-To: References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <51FD57D5.60000@rogers.com> Message-ID: On Tue, Aug 6, 2013 at 2:52 AM, Eric wrote: > On Sat, 3 Aug 2013, James Knott wrote: > >> However, my understanding about probabilities says that while something >> may be unlikely, it's not impossible and, according to chance may even >> happen immediately. > > That is the intuitive paradox. > One could argue that anything that appears to be impossible > is only very improbable, since given a few tweaks you can > make the impossible into something extremely improbable. > However, rational people shouldn't fret about impossible events. > > For example, according to radioactive statistics, it is > possible that all the atoms in any non-supercritical fissile > mass may spontaneous decay, all at once, since each atom has a > finite probability of decaying in the next second. > The total spontaneous decay probability is unimaginably > small. No scientist is concerned with that because, although > mathematically possible, it is practically impossible. > > In a finite observable universe, some things will never happen. > And to make the odds even more improbable, the actual realm > where we exist is a tiny tiny fraction of that observable > universe. My concern about the hashing systems is that, in the absence of sufficient analysis, the whole "super-hyper-infinitely-improbable" measures are estimations, and are not certain to be the actuality. And note that in practice, it's eminently difficult to perfectly validate the precise characteristics of the fissile mass, as what you can know about it tends to come out of statistical analysis of observations. (If we knew when atoms were going to decay, well, that's supposed to be the thing we are completely unable to know, isn't it?!?) If I saw too many atoms decaying all at once, I would be keen to head to the hypothesis that we got the model wrong, and imagined that the material was composed rather differently than was truly the case. Similarly, if I "shuffled" a deck, and then drew 4 aces in a row, I'd be pretty inclined to the hypothesis that this wasn't just random chance, but rather: a) Some exploit in the shuffling system, or b) Perhaps there's more than 4 aces in the deck? And if I saw a bunch of SHA-1 collisions, then either: a) Lotta duplicate things getting hashed, b) Buggy implementation of SHA-1, or c) Something more deeply wrong with SHA-1 are all plausible hypotheses, and it may be quite difficult to distinguish between b) and c), in particular. Practical cryptography is troublesome, because you tend to have a limited set of messages to work with, so it's rather difficult to infer between things like that a), b) and c). Naive users of cryptography (and I think that pretty much includes all of us here; we haven't had to use crypto to protect messages against life-and-death-important attacks) don't know what all things to try to guard against. >> The astrophysicist Brian Greene has some >> interesting comments on this sort of thing, in the realm of infinite >> universes. One thing he mentions is that if the universe is truly >> infinite, then some subset of it, such as the portion within our >> observable limits, must be repeated an infinite number of times. > > Yes, within the framework of theoretical infinities, > everything will happen sometime; so what? That is pure speculation. > That doesn't change the odds within the relatively small > finite (not infinite) realm where we exist. > (Green could be speculating to explain how the laws of > physics appear to be fine-tuned.) > >> Another thing he mentioned was if you shuffle a deck of cards, while >> highly unlikely, one possible outcome is all the cards will be properly >> sorted. This is because no matter how many there are, there are a >> finite number of possible combinations. Once you've shuffled past that >> number of times, and likely well before it, then repeat sequences are >> inevitable. > > In an ideal shuffle, every permutation is equally likely. > There is nothing special about all the cards being properly sorted. > It only seems remarkable because it is easy to recognize. > Or as Feynman satirically pointed out: > > "You know, the most amazing thing happened to me tonight. I > was coming here, on the way to the lecture, and I came in > through the parking lot. And you won't believe what > happened. I saw a car with the license plate ARW 357. Can > you imagine? Of all the millions of license plates in the > state, what was the chance that I would see that particular > one tonight? Amazing!" > > The fallacy in the card deck premise is the phrase "once > you've shuffled past that number of times". > Since you will never reach that number (52!), it's a > non-problem. In principle, there may be 52! combinations; to be sure, usual shufflings won't get anywhere close to that. I imagine that casinos have an active desire to prefer shuffling algorithms that tend to leave cards in "disarray" such that they expect the patterns involving lots of sequences to be particularly unlikely. After all, if players notice that, after a shuffle, the cards are coming out in what they *imagine* to be an interesting order (and I love your Feynman quote here!), someone's going to get beat up. Truly being random isn't as good, in this case, as *appearing* random. -- When confronted by a difficult problem, solve it by reducing it to the question, "How would the Lone Ranger handle this?" -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From scruss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Wed Aug 7 18:29:17 2013 From: scruss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Stewart Russell) Date: Wed, 7 Aug 2013 14:29:17 -0400 Subject: understanding probability In-Reply-To: References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <51FD57D5.60000@rogers.com> Message-ID: You'd be surprised what some casinos do ... or more accurately, don't do: Golden Nugget suing card maker after unshuffled cards pay off big for gamblers: http://www.nj.com/news/index.ssf/2012/08/golden_nugget_suing_card_manuf.html Stewart -------------- next part -------------- An HTML attachment was scrubbed... URL: From thomas.bruce.milne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Wed Aug 7 21:27:18 2013 From: thomas.bruce.milne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Thomas Milne) Date: Wed, 7 Aug 2013 17:27:18 -0400 Subject: World's first sport utility laptop is fully solar-powered and runs Linux : TreeHugger Message-ID: http://www.treehugger.com/gadgets/worlds-first-sport-utility-laptop-fully-solar-powered-and-runs-Linux.html -------------- next part -------------- An HTML attachment was scrubbed... URL: From ekg_ab-FFYn/CNdgSA at public.gmane.org Thu Aug 8 02:03:01 2013 From: ekg_ab-FFYn/CNdgSA at public.gmane.org (E K) Date: Wed, 7 Aug 2013 19:03:01 -0700 (PDT) Subject: understanding probability In-Reply-To: References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <51FD57D5.60000@rogers.com> Message-ID: <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> ________________________________ > From: Christopher Browne >To: TLUG Mailing List >Sent: Wednesday, August 7, 2013 9:11:00 AM >Subject: Re: [TLUG]: understanding probability > > >On Tue, Aug 6, 2013 at 2:52 AM, Eric wrote: >> On Sat, 3 Aug 2013, James Knott wrote: >> >>> However, my understanding about probabilities says that while something >>> may be unlikely, it's not impossible and, according to chance may even >>> happen immediately. >> >> That is the intuitive paradox. >> One could argue that anything that appears to be impossible >> is only very improbable, since given a few tweaks you can >> make the impossible into something extremely improbable. >> However, rational people shouldn't fret about impossible events. >> >> For example, according to radioactive statistics, it is >> possible that all the atoms in any non-supercritical fissile >> mass may spontaneous decay, all at once, since each atom has a >> finite probability of decaying in the next second. >> The total spontaneous decay probability is unimaginably >> small.? No scientist is concerned with that because, although >> mathematically possible, it is practically impossible. >> Well, my take on infinity (and infinitesimal) is that it is just convenient tools?to simplify mathematical derivation, otherwise, as a concept "the machinery of logical and mathematical reasoning also breaks down when applied to infinity" [http://www.thelawofphysics.com/table-of-contents/infinity]. That means, infinity shouldn't be used in describing reality. >> In a finite observable universe, some things will never happen. >> And to make the odds even more improbable, the actual realm >> where we exist is a tiny tiny fraction of that observable >> universe. > But, even without infinity, we know that the universe came about from nothing. If the universe and everything in it can come from nothing, what can be more surprising? >My concern about the hashing systems is that, in the absence of >sufficient analysis, the whole "super-hyper-infinitely-improbable" >measures are estimations, and are not certain to be the actuality. > What is sufficient analysis? An estimate that all experts agree to be sufficient until some one shows otherwise? >And note that in practice, it's eminently difficult to perfectly validate >the precise characteristics of the fissile mass, as what you can >know about it tends to come out of statistical analysis of observations. >(If we knew when atoms were going to decay, well, that's supposed >to be the thing we are completely unable to know, isn't it?!?) > >If I saw too many atoms decaying all at once, I would be keen to >head to the hypothesis that we got the model wrong, and imagined >that the material was composed rather differently than was truly >the case. > >Similarly, if I "shuffled" a deck, and then drew 4 aces in a row, I'd >be pretty inclined to the hypothesis that this wasn't just random >chance, but rather: >a) Some exploit in the shuffling system, or >b) Perhaps there's more than 4 aces in the deck? > >And if I saw a bunch of SHA-1 collisions, then either: >a) Lotta duplicate things getting hashed, >b) Buggy implementation of SHA-1, or >c) Something more deeply wrong with SHA-1 >are all plausible hypotheses, and it may be quite difficult to >distinguish between b) and c), in particular. > >Practical cryptography is troublesome, because you tend to have >a limited set of messages to work with, so it's rather difficult to >infer between things like that a), b) and c). > >Naive users of cryptography (and I think that pretty much includes >all of us here; we haven't had to use crypto to protect messages >against life-and-death-important attacks) don't know what all >things to try to guard against. > There are two ways to guard yourself against security risks. Either you should know what you are doing, or transfer the risk to someone who is willing to take the risk. When one does not know what they are doing or can not transfer risk, they rely on trust system - by using security system that someone who has higher security stake uses. For example, some one may say, an encryption system used by banks is good enough for my need. >>> The astrophysicist Brian Greene has some >>> interesting comments on this sort of thing, in the realm of infinite >>> universes.? One thing he mentions is that if the universe is truly >>> infinite, then some subset of it, such as the portion within our >>> observable limits, must be repeated an infinite number of times. >> >> Yes, within the framework of theoretical infinities, >> everything will happen sometime; so what?? That is pure speculation. >> That doesn't change the odds within the relatively small >> finite (not infinite) realm where we exist. >> (Green could be speculating to explain how the laws of >> physics appear to be fine-tuned.) >> >>> Another thing he mentioned was if you shuffle a deck of cards, while >>> highly unlikely, one possible outcome is all the cards will be properly >>> sorted.? This is because no matter how many there are, there are a >>> finite number of possible combinations.? Once you've shuffled past that >>> number of times, and likely well before it, then repeat sequences are >>> inevitable. >> >> In an ideal shuffle, every permutation is equally likely. >> There is nothing special about all the cards being properly sorted. >> It only seems remarkable because it is easy to recognize. >> Or as Feynman satirically pointed out: >> >>???"You know, the most amazing thing happened to me tonight. I >>???was coming here, on the way to the lecture, and I came in >>???through the parking lot. And you won't believe what >>???happened. I saw a car with the license plate ARW 357. Can >>???you imagine? Of all the millions of license plates in the >>???state, what was the chance that I would see that particular >>???one tonight? Amazing!" >> >> The fallacy in the card deck premise is the phrase "once >> you've shuffled past that number of times". >> Since you will never reach that number (52!), it's a >> non-problem. > >In principle, there may be 52! combinations; to be sure, usual >shufflings won't get anywhere close to that. > >I imagine that casinos have an active desire to prefer shuffling >algorithms that tend to leave cards in "disarray" such that they >expect the patterns involving lots of sequences to be particularly >unlikely. > >After all, if players notice that, after a shuffle, the cards are >coming out in what they *imagine* to be an interesting order (and I >love your Feynman quote here!), someone's going to get beat up. > >Truly being random isn't as good, in this case, as *appearing* random. >-- >When confronted by a difficult problem, solve it by reducing it to the >question, "How would the Lone Ranger handle this?" >-- >The Toronto Linux Users Group.? ? ? Meetings: http://gtalug.org/ >TLUG requests: Linux topics, No HTML, wrap text below 80 columns >How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > > EK -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From ekg_ab-FFYn/CNdgSA at public.gmane.org Thu Aug 8 02:05:48 2013 From: ekg_ab-FFYn/CNdgSA at public.gmane.org (E K) Date: Wed, 7 Aug 2013 19:05:48 -0700 (PDT) Subject: How to get started on mobile development In-Reply-To: <52013830.8030609-w5ExpX8uLjYAvxtiuMwx3w@public.gmane.org> References: <52013830.8030609@sobac.com> Message-ID: <1375927548.30885.YahooMailNeo@web161904.mail.bf1.yahoo.com> Hi, I got a project for mobile app development. I have no idea about how to get started with such a project. Any idea or pointer will be greatly appreciated. Thanks, EK -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Thu Aug 8 02:08:33 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Wed, 07 Aug 2013 22:08:33 -0400 Subject: understanding probability In-Reply-To: <1375927381.48685.YahooMailNeo-/W4/QBBOCLIeBhY5O9xny5EhsgyP+Z75VpNB7YpNyf8@public.gmane.org> References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <51FD57D5.60000@rogers.com> <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> Message-ID: <5202FDA1.9000604@rogers.com> E K wrote: > But, even without infinity, we know that the universe came about from nothing. If the universe and everything in it can come from nothing, what can be more surprising? That might not be the case. Again, according to Brian Greene, there are some indications there was something else earlier. Some think the universe might be cyclic. Another possibility is the universe is but one bubble in a foam of universes. He has a few other suggestions about this. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From thoriumbr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 8 02:57:05 2013 From: thoriumbr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Mauro Souza) Date: Wed, 7 Aug 2013 23:57:05 -0300 Subject: How to get started on mobile development In-Reply-To: <1375927548.30885.YahooMailNeo-/W4/QBBOCLLK0anN2EpufZEhsgyP+Z75VpNB7YpNyf8@public.gmane.org> References: <52013830.8030609@sobac.com> <1375927548.30885.YahooMailNeo@web161904.mail.bf1.yahoo.com> Message-ID: A very easy framework is Game Closure (www.gameclosure.com). I installed it a couple months ago, messed with it a little but never got time to do anything serious. But looks interesting, and creates apps for Android and iOS. It's javascript/css/html5 based, and says it can achieve native speeds. Mauro http://mauro.limeiratem.com - registered Linux User: 294521 Scripture is both history, and a love letter from God. 2013/8/7 E K > Hi, > > I got a project for mobile app development. I have no idea about how to > get started with such a project. Any idea or pointer will be greatly > appreciated. > > Thanks, > EK > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -------------- next part -------------- An HTML attachment was scrubbed... URL: From antoniosun-N9AOi2cAC9ZBDgjK7y7TUQ at public.gmane.org Thu Aug 8 04:14:33 2013 From: antoniosun-N9AOi2cAC9ZBDgjK7y7TUQ at public.gmane.org (Antonio Sun) Date: Thu, 8 Aug 2013 00:14:33 -0400 Subject: Input on future mobile platform In-Reply-To: References: Message-ID: On Mon, Aug 5, 2013 at 7:35 PM, Christopher Browne wrote: > I think there's not likely to be anyone that has a coherent idea as to > what The Next Thing will be. That's not a problem at all. Everyone has their own view, we don't need to reach any coherent idea at all. What's important to me is to see if I've missed anything while taking my view. > Further, the notion that it's Mostly About The Technology seems > laughable, because the customers that *buy* millions of mobile devices > aren't about the technology. Agree. What I forgot to emphasis in my OP was that, the reason that I was asking was that, being a programmer that want to get into the mobile programming world, with zero previous experience, I am trying to catch the "next wave", because I'm not into the Apple's ObjectC niche market, and I don't want to get into the Java-based Android programming either. I'm planning to get my foot wet into something that'll be cross platform, i.e. good for phone, tablet, and desktop as well. However, that's easy to set a goal than to find where actually to go. On Mon, Aug 5, 2013 at 3:34 PM, William Muriithi wrote: >> What's your idea about the near future mobile platform? What's in >> trending? Which of today's technology do you think will take the lead >> tomorrow? > > . . . > >> The reason that I'm asking is that, although the Java-based Android is in >> domain of current mobile development platform (in my so-called technology >> driven world of course), I don't think it will be future, and I don't >> believe Google is happy about the Java-based platform either. What do you >> think? Which one will win over tomorrow? >> > What make you think Google is not happy about it? Never seen any article > that imply the hate Java, they actually used it a lot even before android I tend to agree more with the article Writing native Android applications with Javascript? Not yet. http://www.freesoftwaremagazine.com/articles/writing_native_android_applications_javascript_not_yet I.e., It's all about timing. Google/Android chose Java because there were no other good alternatives. Now things have been completely changed -- "So, what has changed? Two words: 1) Chrome 2) Javascript I am convinced that Chrome and Javascript changed the whole IT landscape radically." . . . "In the end, if Google had to decide how to build Android in 2008 rather than 2005, I have little doubt that they would have picked Javascript as their language of choice. Instead, Android has fully embraced Java"... Quite agree with that, so I'm quoting straight from the article. >> I have my own view on this, but would like to know yours as well. > Hmm, weird. So what if everybody adopt similar strategy? Alright, alright. Let me share my view first, and anyone can share theirs as well. Again, we don't need to agree with each other. I tend to think that the discussion will be kind of a reminder -- "Hey, here is another way to look at it". First of all, I want to emphasis again, being a programmer, I think it *is* the technology renovation that lead to the "surviving/leading" mobile phone or tablet, It is not about the consumer at all. Anyone , any company who is not actively seeking the next renovation will be end up like blackberry/Nokia/Motorola/etc. So what's trending? Again, being a programmer who embrace the open-source world most, I care more on what's in Google's mind than in Apple's. I thinking Google is putting more and more their bet on Javascript and Chrome (concurring the above article). Android is not the *only* popular mobile OS that Google owns. The other popular mobile OS that Google owns is Chrome OS, the product being Chrome Book. This is what Google prefers for now I believe. There is an estimation that the Chrome Book sales will increase by 300% this year. Look at what Google has been putting their efforts in now, that'll pretty safely predict what the future mobile product/platform etc would be. Has anyone see the Racer demo at Google I/O 2013? That tells what Google has been putting their efforts in now. "Racer was built to show what?s possible on today?s mobile devices using an entirely in-browser experience. The goal was to create a touch-enabled experience that plays out across multiple screens (and speakers). " Google says "the web technologies that made this Chrome Experiment [would be] ?street-legal? in a couple of months". The web technologies used include: - the solution is cross platform, works for either phones or tablets (different screen sizes of course), with: - 2D vector drawings on HTML5 Canvas - sound is shared and synced across multiple devices using the Web Audio API (Each device plays one slice of Giorgio Moroder?s symphony of sound?requiring five devices at once to hear his full composition. ) - syncing the phones or tablets is done by WebSockets, which enables rapid two-way communication between devices. - the next step is to use WebRTC data channels?the next generation of speedy Web communication Details available from http://blog.chromium.org/2013/06/race-across-screens-and-platforms.html To recap, to me, Google is working at a *cross platform* solution that works for phones, tablets or desktops, and this "pure web-based" solution is their goal, and they have already achieved it. See, no Java in sight at all! So, being a programmer who has zero previous experience in the mobile programming, if I start learning now from Java-based Android programming, I'll completely miss the point if I want to catch up with the next/leading wave. Now, what's your view on what's trending in new mobile technology? Thanks -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org Thu Aug 8 04:33:20 2013 From: jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org (Jamon Camisso) Date: Thu, 08 Aug 2013 00:33:20 -0400 Subject: Input on future mobile platform In-Reply-To: References: Message-ID: <52031F90.1010301@utoronto.ca> On 13-08-08 12:14 AM, Antonio Sun wrote: > Now, what's your view on what's trending in new mobile technology? Forget trends, they come and go. Find a problem that you want to solve that is specific to a phone or tablet OS and then use the tools or platform that is best suited to solving said problem. If it is a relatively straightforward implementation, consider using PhoneGap, since it will help you write once and deploy on multiple platforms using HTML5/CSS3/JS: http://phonegap.com/about/ These are widely implemented technologies on mobile platforms, and as such aren't going anywhere. They are increasingly the easiest way to achieve any semblance of cross-platform compatibility considering the variety of computing platforms that are in use these days. Write it properly using these and a laptop/desktop version will take little work to port as well. Jamon -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From gilesorr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 8 13:17:32 2013 From: gilesorr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Giles Orr) Date: Thu, 8 Aug 2013 09:17:32 -0400 Subject: How to get started on mobile development In-Reply-To: References: <52013830.8030609@sobac.com> <1375927548.30885.YahooMailNeo@web161904.mail.bf1.yahoo.com> Message-ID: On 7 August 2013 22:57, Mauro Souza wrote: > A very easy framework is Game Closure (www.gameclosure.com). I installed > it a couple months ago, messed with it a little but never got time to do > anything serious. But looks interesting, and creates apps for Android and > iOS. > It's javascript/css/html5 based, and says it can achieve native speeds. > > Mauro > http://mauro.limeiratem.com - registered Linux User: 294521 > Scripture is both history, and a love letter from God. > > > 2013/8/7 E K > >> Hi, >> >> I got a project for mobile app development. I have no idea about how to >> get started with such a project. Any idea or pointer will be greatly >> appreciated. >> >> Thanks, >> EK >> -- >> The Toronto Linux Users Group. Meetings: http://gtalug.org/ >> TLUG requests: Linux topics, No HTML, wrap text below 80 columns >> How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists >> > > I looked at doing Android development. Getting started was so painful that I never really got off the ground (although that may have been pre-ordained for other reasons). But the most obvious place to start is here: https://developer.android.com/sdk/index.html You can get the SDK which either includes or requires Eclipse (ugh) and Android emulators for every rev of the OS you can imagine. Expect to need at least 2Gig of HD space (that's gigabytes, it's immense). One of the things that frustrated me is that a dummy Android project has to have something on the order of six directories and 12 files, just to compile and do NOTHING: the Dalvik set-up is that complex. Also interesting if you have an Android device with a keyboard you can actually program on is AIDE: https://play.google.com/store/apps/details?id=com.aide.ui It's an IDE for Android development that runs on Android. I did no real development with it, but succeeded in compiling and running a dummy app far more easily than with the Android SDK on a Linux machine. Might be worth looking at. Mauro's post relates to doing stuff in HTML/JS/CSS, and that may be a saner way to work. You have a much better chance of it also working on iOS if that's of interest to you. Beyond that I know nothing about iOS development. Finally, I'll put in a pitch for a few favourite apps related to development: if you have a physical keyboard, "vim touch" is an almost-complete recreation of (almost) everyone's favourite editor for Android. If you don't have a physical keyboard, "The Hacker's Keyboard" (hey, it's got CTRL and arrow keys) and the "Jota" and "Jota+" editor are excellent. -- Giles http://www.gilesorr.com/ gilesorr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org -------------- next part -------------- An HTML attachment was scrubbed... URL: From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Thu Aug 8 14:18:32 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Thu, 8 Aug 2013 10:18:32 -0400 Subject: Input on future mobile platform In-Reply-To: References: Message-ID: <20130808141832.GA22675@csclub.uwaterloo.ca> On Thu, Aug 08, 2013 at 12:14:33AM -0400, Antonio Sun wrote: > What I forgot to emphasis in my OP was that, the reason that I was > asking was that, being a programmer that want to get into the mobile > programming world, with zero previous experience, I am trying to catch > the "next wave", because I'm not into the Apple's ObjectC niche > market, and I don't want to get into the Java-based Android > programming either. Well out of the current mobile development systems, I think Apple's is the only one I even remotely like. Blackberry and Android use java, Windows Phone uses .net (which is pretty much just Microsoft's version of java), and Apple uses ObjectiveC. Unfortunately I hate Apple's corporate policies, even though their hardware and software is very nice. No wonder I don't own any smartphone. > I'm planning to get my foot wet into something that'll be cross > platform, i.e. good for phone, tablet, and desktop as well. However, > that's easy to set a goal than to find where actually to go. Unfortunately, different systems will have different APIs, so cross platform will somehow involve yet another abstraction layer if you don't want to write different code for each system for at least part of your application. Yet another layer means yet more slowdown and waste of resources, which is bad enough already on the various smart phones. So there simply is no good way to do that. > I tend to agree more with the article > > Writing native Android applications with Javascript? Not yet. > http://www.freesoftwaremagazine.com/articles/writing_native_android_applications_javascript_not_yet http://sealedabstract.com/rants/why-mobile-web-apps-are-slow/ javascript will never be the solution given battery life and performance really does matter. > I.e., It's all about timing. Google/Android chose Java because there > were no other good alternatives. Now things have been completely > changed -- "So, what has changed? Two words: 1) Chrome 2) Javascript I > am convinced that Chrome and Javascript changed the whole IT landscape > radically." . . . No it really hasn't changed. Javascript has gotten somewhat better, but there really isn't anything left you can do to javascript to make it faster, and it is still 5 times slower than native code. You need a better language than javascript if you want a chance to fix this. Then you need to convince every browser to support your new better and more efficient language in order to get cross platform to be an option again. Good luck. > "In the end, if Google had to decide how to build Android in 2008 > rather than 2005, I have little doubt that they would have picked > Javascript as their language of choice. Instead, Android has fully > embraced Java"... > > Quite agree with that, so I'm quoting straight from the article. I don't. It is wrong. > Alright, alright. Let me share my view first, and anyone can share > theirs as well. Again, we don't need to agree with each other. I tend > to think that the discussion will be kind of a reminder -- "Hey, here > is another way to look at it". > > First of all, I want to emphasis again, being a programmer, I think it > *is* the technology renovation that lead to the "surviving/leading" > mobile phone or tablet, It is not about the consumer at all. Anyone , > any company who is not actively seeking the next renovation will be > end up like blackberry/Nokia/Motorola/etc. > > So what's trending? Well it seems twitter and facebook and such are. Not sure why that is. Certainly not because they are particularly good, they are just popular. > Again, being a programmer who embrace the open-source world most, I > care more on what's in Google's mind than in Apple's. I thinking > Google is putting more and more their bet on Javascript and Chrome > (concurring the above article). Android is not the *only* popular > mobile OS that Google owns. The other popular mobile OS that Google > owns is Chrome OS, the product being Chrome Book. This is what Google > prefers for now I believe. There is an estimation that the Chrome Book > sales will increase by 300% this year. Chrome OS is popular? Since when? Also increasing their sales by 300% isn't much given I dout their current sales are anything impressive. > Look at what Google has been putting their efforts in now, that'll > pretty safely predict what the future mobile product/platform etc > would be. Has anyone see the Racer demo at Google I/O 2013? That tells > what Google has been putting their efforts in now. "Racer was built > to show what?s possible on today?s mobile devices using an entirely > in-browser experience. The goal was to create a touch-enabled > experience that plays out across multiple screens (and speakers). " > Google says "the web technologies that made this Chrome Experiment > [would be] ?street-legal? in a couple of months". The web technologies > used include: > > - the solution is cross platform, works for either phones or tablets > (different screen sizes of course), with: > - 2D vector drawings on HTML5 Canvas > - sound is shared and synced across multiple devices using the Web > Audio API (Each device plays one slice of Giorgio Moroder?s symphony > of sound?requiring five devices at once to hear his full composition. > ) > - syncing the phones or tablets is done by WebSockets, which enables > rapid two-way communication between devices. > - the next step is to use WebRTC data channels?the next generation of > speedy Web communication All neat, but still not anywhere near the performance of native code. > Details available from > http://blog.chromium.org/2013/06/race-across-screens-and-platforms.html > > To recap, to me, Google is working at a *cross platform* solution that > works for phones, tablets or desktops, and this "pure web-based" > solution is their goal, and they have already achieved it. See, no > Java in sight at all! Pure web conviniently forces you to be online where they can track you and advertise to you all the time. Of course that is _their_ goal. > So, being a programmer who has zero previous experience in the mobile > programming, if I start learning now from Java-based Android > programming, I'll completely miss the point if I want to catch up with > the next/leading wave. > > Now, what's your view on what's trending in new mobile technology? I think the current state of mobile devices sucks, and I mainly blame android for destroying what was looking slightly promising (although it may all have failed anyhow). Also Steve Jobs was amazing at what he did and a complete ass hole too. Too bad he couldn't have just ben the first and not such a complete control freak. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Thu Aug 8 15:00:43 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Thu, 8 Aug 2013 11:00:43 -0400 Subject: How to get started on mobile development In-Reply-To: References: <52013830.8030609@sobac.com> <1375927548.30885.YahooMailNeo@web161904.mail.bf1.yahoo.com> Message-ID: <20130808150043.GB22675@csclub.uwaterloo.ca> On Wed, Aug 07, 2013 at 11:57:05PM -0300, Mauro Souza wrote: > A very easy framework is Game Closure (www.gameclosure.com). I installed it > a couple months ago, messed with it a little but never got time to do > anything serious. But looks interesting, and creates apps for Android and > iOS. > It's javascript/css/html5 based, and says it can achieve native speeds. Well then it obviously lies. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From psema4-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 8 15:28:09 2013 From: psema4-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Scott Elcomb) Date: Thu, 8 Aug 2013 11:28:09 -0400 Subject: How to get started on mobile development In-Reply-To: <1375927548.30885.YahooMailNeo-/W4/QBBOCLLK0anN2EpufZEhsgyP+Z75VpNB7YpNyf8@public.gmane.org> References: <52013830.8030609@sobac.com> <1375927548.30885.YahooMailNeo@web161904.mail.bf1.yahoo.com> Message-ID: On Wed, Aug 7, 2013 at 10:05 PM, E K wrote: > Hi, > > I got a project for mobile app development. I have no idea about how to get started with such a project. Any idea or pointer will be greatly appreciated. Start with the basics - what platform(s) do you need to support. Is the project IOS-specific? Android? Blackberry? Must the project be written using "native" SDK's or can it be an HTML-based app? If it can be HTML-based, I'd recommend a look at Responsive Web Design[1] techniques and Phonegap[2]. Personally, I tend to prefer HTML5 over native but there are exceptions (some things just aren't available via the browser yet). Anyway, context regarding the project requirements should help narrow down what you need to learn. [1] [2] -- Scott Elcomb @psema4 on Twitter / Identi.ca / Github & more Atomic OS: Self Contained Microsystems http://code.google.com/p/atomos/ Member of the Pirate Party of Canada http://www.pirateparty.ca/ -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From thoriumbr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 8 17:09:55 2013 From: thoriumbr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Mauro Souza) Date: Thu, 8 Aug 2013 14:09:55 -0300 Subject: How to get started on mobile development In-Reply-To: <20130808150043.GB22675-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <52013830.8030609@sobac.com> <1375927548.30885.YahooMailNeo@web161904.mail.bf1.yahoo.com> <20130808150043.GB22675@csclub.uwaterloo.ca> Message-ID: I took a better look on their site, and found this: "Native speeds on iOS and Android iOS and Android production games built on top of OpenGL for maximum performance When you?re ready to launch your game, run a single command to package either iOS or android binaries ready for upload to the Google Play Store or Apple?s App Store. Your game will run at native speeds, taking full advantage of the powerful GPUs and CPUs in modern smartphones. We?ve handled all the differences between iOS and Android for you." Looks like you develop your game/app/demo using html5/javascript, and the SDK compiles it on a native format. It will not run javascript on the mobile device. Mauro http://mauro.limeiratem.com - registered Linux User: 294521 Scripture is both history, and a love letter from God. 2013/8/8 Lennart Sorensen > On Wed, Aug 07, 2013 at 11:57:05PM -0300, Mauro Souza wrote: > > A very easy framework is Game Closure (www.gameclosure.com). I > installed it > > a couple months ago, messed with it a little but never got time to do > > anything serious. But looks interesting, and creates apps for Android and > > iOS. > > It's javascript/css/html5 based, and says it can achieve native speeds. > > Well then it obviously lies. > > -- > Len Sorensen > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -------------- next part -------------- An HTML attachment was scrubbed... URL: From ted.leslie-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 8 17:25:23 2013 From: ted.leslie-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (ted leslie) Date: Thu, 8 Aug 2013 13:25:23 -0400 Subject: How to get started on mobile development In-Reply-To: <1375927548.30885.YahooMailNeo-/W4/QBBOCLLK0anN2EpufZEhsgyP+Z75VpNB7YpNyf8@public.gmane.org> References: <52013830.8030609@sobac.com> <1375927548.30885.YahooMailNeo@web161904.mail.bf1.yahoo.com> Message-ID: If you are doing high end stuff, mono with http://xamarin.com/ is the way to go. Its not write once, deploy on many, but the core logic code (c#) with be the same, and the particulars of camera, gps, etc, will change a bit depending on phone, but even then they have stuff to blend them together. For games , there is http://monogame.codeplex.com/ and the phenomenal Unity 3d http://unity3d.com/unity/multiplatform/mobile also uses mono This stuff isn't free :( but its what the big boys use now. Your SOL on blackberry with this environment. But it will be good for ubuntu phono (when the time comes). Plus whatever logic you write will work on linux, windows, Mac, Ios, android, nintendo wii, xboxN, psN, etc. -tl On Wed, Aug 7, 2013 at 10:05 PM, E K wrote: > Hi, > > I got a project for mobile app development. I have no idea about how to > get started with such a project. Any idea or pointer will be greatly > appreciated. > > Thanks, > EK > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -------------- next part -------------- An HTML attachment was scrubbed... URL: From stephen-d-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Thu Aug 8 18:53:37 2013 From: stephen-d-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (Stephen) Date: Thu, 08 Aug 2013 14:53:37 -0400 Subject: [OT] Free US Robotics v34 Modem Message-ID: <5203E931.1010200@rogers.com> I have had this on the shelf for many years and before I take for recycling I thought I would offer it up here in case anyone has a use for it. If so, let me know! -- Stephen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Thu Aug 8 19:04:32 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Thu, 8 Aug 2013 15:04:32 -0400 Subject: How to get started on mobile development In-Reply-To: References: <52013830.8030609@sobac.com> <1375927548.30885.YahooMailNeo@web161904.mail.bf1.yahoo.com> <20130808150043.GB22675@csclub.uwaterloo.ca> Message-ID: <20130808190432.GC22675@csclub.uwaterloo.ca> On Thu, Aug 08, 2013 at 02:09:55PM -0300, Mauro Souza wrote: > I took a better look on their site, and found this: > "Native speeds on iOS and Android > iOS and Android production games built on top of OpenGL for maximum > performance > When you?re ready to launch your game, run a single command to package > either iOS or android binaries ready for upload to the Google Play Store or > Apple?s App Store. Your game will run at native speeds, taking full > advantage of the powerful GPUs and CPUs in modern smartphones. We?ve > handled all the differences between iOS and Android for you." > > Looks like you develop your game/app/demo using html5/javascript, and the > SDK compiles it on a native format. It will not run javascript on the > mobile device. Well that's sounding rather unlikely. Also openGL doesn't solve everything a game needs. I also think javascript is a dreadful language to work in. I see them using node.js in the devkit, and it certainly does not have native performance, and neither does v8 in chrome or whatever they end up using on iOS. For simply games, it probably runs fast enough to work, but certainly means using a lot more CPU and battery life than the same game written natively would. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Thu Aug 8 19:06:32 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Thu, 8 Aug 2013 15:06:32 -0400 Subject: [OT] Free US Robotics v34 Modem In-Reply-To: <5203E931.1010200-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <5203E931.1010200@rogers.com> Message-ID: <20130808190632.GD22675@csclub.uwaterloo.ca> On Thu, Aug 08, 2013 at 02:53:37PM -0400, Stephen wrote: > I have had this on the shelf for many years and before I take for > recycling I thought I would offer it up here in case anyone has a > use for it. > > If so, let me know! Might want to tell people the model, and things like whether it is USB or serial or internal (ISA or PCI), etc. And of course a Courier is much more intesting than a Sportster. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From stephen-d-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Thu Aug 8 19:07:24 2013 From: stephen-d-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (Stephen) Date: Thu, 08 Aug 2013 15:07:24 -0400 Subject: [OT] Free US Robotics v34 Modem In-Reply-To: <20130808190632.GD22675-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <5203E931.1010200@rogers.com> <20130808190632.GD22675@csclub.uwaterloo.ca> Message-ID: <5203EC6C.5010009@rogers.com> On 13-08-08 03:06 PM, Lennart Sorensen wrote: > On Thu, Aug 08, 2013 at 02:53:37PM -0400, Stephen wrote: >> I have had this on the shelf for many years and before I take for >> recycling I thought I would offer it up here in case anyone has a >> use for it. >> >> If so, let me know! > Might want to tell people the model, and things like whether it is USB > or serial or internal (ISA or PCI), etc. > > And of course a Courier is much more intesting than a Sportster. > Yes, of course. It is external, 25 pin serial port, and it is a Courier. -- Stephen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Thu Aug 8 20:22:39 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Thu, 8 Aug 2013 16:22:39 -0400 Subject: [OT] Free US Robotics v34 Modem In-Reply-To: <5203EC6C.5010009-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <5203E931.1010200@rogers.com> <20130808190632.GD22675@csclub.uwaterloo.ca> <5203EC6C.5010009@rogers.com> Message-ID: <20130808202239.GE22675@csclub.uwaterloo.ca> On Thu, Aug 08, 2013 at 03:07:24PM -0400, Stephen wrote: > Yes, of course. > > It is external, 25 pin serial port, and it is a Courier. If I didn't already have a courier v.everything, I would think that would be nice to have. But I don't need two dial up modems. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From ekg_ab-FFYn/CNdgSA at public.gmane.org Thu Aug 8 20:26:50 2013 From: ekg_ab-FFYn/CNdgSA at public.gmane.org (E K) Date: Thu, 8 Aug 2013 13:26:50 -0700 (PDT) Subject: How to get started on mobile development In-Reply-To: References: <52013830.8030609@sobac.com> <1375927548.30885.YahooMailNeo@web161904.mail.bf1.yahoo.com> Message-ID: <1375993610.37226.YahooMailNeo@web161901.mail.bf1.yahoo.com> >________________________________ > From: Giles Orr >To: tlug >Sent: Thursday, August 8, 2013 7:17:32 AM >Subject: Re: [TLUG]: How to get started on mobile development > > > >On 7 August 2013 22:57, Mauro Souza wrote: > >A very easy framework is Game Closure (www.gameclosure.com). I installed it a couple months ago, messed with it a little but never got time to do anything serious. But looks interesting, and creates apps for Android and iOS. >>It's javascript/css/html5 based, and says it can achieve native speeds. >> >> >> >>Mauro >>http://mauro.limeiratem.com - registered Linux User: 294521 >>Scripture is both history, and a love letter from God. >> >> >> >>2013/8/7 E K >> >>Hi, >>> >>>I got a project for mobile app development. I have no idea about how to get started with such a project. Any idea or pointer will be greatly appreciated. >>> >>>Thanks, >>>EK >>>-- >>>The Toronto Linux Users Group. ? ? ?Meetings: http://gtalug.org/ >>>TLUG requests: Linux topics, No HTML, wrap text below 80 columns >>>How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists >>> >> > >I looked at doing Android development.? Getting started was so painful that I never really got off the ground (although that may have been pre-ordained for other reasons).? But the most obvious place to start is here: > >https://developer.android.com/sdk/index.html > > >You can get the SDK which either includes or requires Eclipse (ugh) and Android emulators for every rev of the OS you can imagine.? Expect to need at least 2Gig of HD space (that's gigabytes, it's immense). > > >One of the things that frustrated me is that a dummy Android project has to have something on the order of six directories and 12 files, just to compile and do NOTHING: the Dalvik set-up is that complex.? > > > >Also interesting if you have an Android device with a keyboard you can actually program on is AIDE: > >https://play.google.com/store/apps/details?id=com.aide.ui > > >It's an IDE for Android development that runs on Android.? I did no real development with it, but succeeded in compiling and running a dummy app far more easily than with the Android SDK on a Linux machine.? Might be worth looking at. > > > >Mauro's post relates to doing stuff in HTML/JS/CSS, and that may be a saner way to work.? You have a much better chance of it also working on iOS if that's of interest to you.? Beyond that I know nothing about iOS development. > > >Finally, I'll put in a pitch for a few favourite apps related to development: if you have a physical keyboard, "vim touch" is an almost-complete recreation of (almost) everyone's favourite editor for Android.? If you don't have a physical keyboard, "The Hacker's Keyboard" (hey, it's got CTRL and arrow keys) and the "Jota" and "Jota+" editor are excellent. > > >-- >Giles >http://www.gilesorr.com/ >gilesorr at gmail.com > > Thanks to you both. I will take a look at them. EK -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From antoniosun-N9AOi2cAC9ZBDgjK7y7TUQ at public.gmane.org Fri Aug 9 04:26:20 2013 From: antoniosun-N9AOi2cAC9ZBDgjK7y7TUQ at public.gmane.org (Antonio Sun) Date: Fri, 9 Aug 2013 00:26:20 -0400 Subject: Next week's meeting Message-ID: Hi, Where exactly would next week's meeting be? The http://gtalug.org/wiki/Meetings:2013-08 says: George Vari Engineering and Computing Centre *235* Church Street, Room 211 Ryerson University while the Google Maps says *245*. Please advice. PS. Scott, CCing you in case my email can't reach the group (happened yesterday). Please CC me when reply. Thanks -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From gyre-Lmt0BfyYGMw at public.gmane.org Fri Aug 9 09:40:36 2013 From: gyre-Lmt0BfyYGMw at public.gmane.org (Eric B) Date: Fri, 9 Aug 2013 05:40:36 -0400 Subject: understanding probability In-Reply-To: <1375927381.48685.YahooMailNeo-/W4/QBBOCLIeBhY5O9xny5EhsgyP+Z75VpNB7YpNyf8@public.gmane.org> References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <51FD57D5.60000@rogers.com> <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> Message-ID: <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> > ________________________________ >> From: Christopher Browne >>To: TLUG Mailing List >>Sent: Wednesday, August 7, 2013 9:11:00 AM >>Subject: Re: [TLUG]: understanding probability >> >> >>On Tue, Aug 6, 2013 at 2:52 AM, Eric wrote: >>> On Sat, 3 Aug 2013, James Knott wrote: >>> >>>> However, my understanding about probabilities says that while >>>> something >>>> may be unlikely, it's not impossible and, according to chance may even >>>> happen immediately. >>> >>> That is the intuitive paradox. >>> One could argue that anything that appears to be impossible >>> is only very improbable, since given a few tweaks you can >>> make the impossible into something extremely improbable. >>> However, rational people shouldn't fret about impossible events. >>> >>> For example, according to radioactive statistics, it is >>> possible that all the atoms in any non-supercritical fissile >>> mass may spontaneous decay, all at once, since each atom has a >>> finite probability of decaying in the next second. >>> The total spontaneous decay probability is unimaginably >>> small.? No scientist is concerned with that because, although >>> mathematically possible, it is practically impossible. >>> > > Well, my take on infinity (and infinitesimal) is that it is just > convenient tools?to simplify mathematical derivation, otherwise, as a > concept "the machinery of logical and mathematical reasoning also breaks > down when applied to infinity" > [http://www.thelawofphysics.com/table-of-contents/infinity]. That means, > infinity shouldn't be used in describing reality. To put it more simply, infinity doesn't exist. >>> In a finite observable universe, some things will never happen. >>> And to make the odds even more improbable, the actual realm >>> where we exist is a tiny tiny fraction of that observable >>> universe. >> > > But, even without infinity, we know that the universe came about from > nothing. If the universe and everything in it can come from nothing, what > can be more surprising? No one knows that. >>My concern about the hashing systems is that, in the absence of >>sufficient analysis, the whole "super-hyper-infinitely-improbable" >>measures are estimations, and are not certain to be the actuality. I share your concern that this is the weakness, but I wouldn't say there has been insufficient analysis. >>And note that in practice, it's eminently difficult to perfectly validate >>the precise characteristics of the fissile mass, as what you can >>know about it tends to come out of statistical analysis of observations. >>(If we knew when atoms were going to decay, well, that's supposed >>to be the thing we are completely unable to know, isn't it?!?) >> >>If I saw too many atoms decaying all at once, I would be keen to >>head to the hypothesis that we got the model wrong, and imagined >>that the material was composed rather differently than was truly >>the case. The last thing you should consider is that the physics model is wrong. >>Similarly, if I "shuffled" a deck, and then drew 4 aces in a row, I'd >>be pretty inclined to the hypothesis that this wasn't just random >>chance, but rather: >>a) Some exploit in the shuffling system, or >>b) Perhaps there's more than 4 aces in the deck? >> >>And if I saw a bunch of SHA-1 collisions, then either: >>a) Lotta duplicate things getting hashed, >>b) Buggy implementation of SHA-1, or >>c) Something more deeply wrong with SHA-1 >>are all plausible hypotheses, and it may be quite difficult to >>distinguish between b) and c), in particular. Again, option c) is he least plausible since no one has found a false collision. >>>> The astrophysicist Brian Greene has some >>>> interesting comments on this sort of thing, in the realm of infinite >>>> universes.? One thing he mentions is that if the universe is truly >>>> infinite, then some subset of it, such as the portion within our >>>> observable limits, must be repeated an infinite number of times. >>> >>> Yes, within the framework of theoretical infinities, >>> everything will happen sometime; so what?? That is pure speculation. >>> That doesn't change the odds within the relatively small >>> finite (not infinite) realm where we exist. >>> (Green could be speculating to explain how the laws of >>> physics appear to be fine-tuned.) >>> >>>> Another thing he mentioned was if you shuffle a deck of cards, while >>>> highly unlikely, one possible outcome is all the cards will be >>>> properly >>>> sorted.? This is because no matter how many there are, there are a >>>> finite number of possible combinations.? Once you've shuffled past >>>> that >>>> number of times, and likely well before it, then repeat sequences are >>>> inevitable. >>> >>> In an ideal shuffle, every permutation is equally likely. >>> There is nothing special about all the cards being properly sorted. >>> It only seems remarkable because it is easy to recognize. >>> Or as Feynman satirically pointed out: >>> >>>???"You know, the most amazing thing happened to me tonight. I >>>???was coming here, on the way to the lecture, and I came in >>>???through the parking lot. And you won't believe what >>>???happened. I saw a car with the license plate ARW 357. Can >>>???you imagine? Of all the millions of license plates in the >>>???state, what was the chance that I would see that particular >>>???one tonight? Amazing!" >>> >>> The fallacy in the card deck premise is the phrase "once >>> you've shuffled past that number of times". >>> Since you will never reach that number (52!), it's a >>> non-problem. >> >>In principle, there may be 52! combinations; to be sure, usual >>shufflings won't get anywhere close to that. Yes. I was talking about "ideal" shuffling. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From scott-lxSQFCZeNF4 at public.gmane.org Fri Aug 9 14:18:21 2013 From: scott-lxSQFCZeNF4 at public.gmane.org (Scott Sullivan) Date: Fri, 09 Aug 2013 10:18:21 -0400 Subject: Next week's meeting In-Reply-To: References: Message-ID: <5204FA2D.1020601@ss.org> On 08/09/2013 12:26 AM, Antonio Sun wrote: > Hi, > > Where exactly would next week's meeting be? > > The http://gtalug.org/wiki/Meetings:2013-08 says: > > George Vari Engineering and Computing Centre > *235* Church Street, Room 211 > Ryerson University > > while the Google Maps says *245*. > > Please advice. It is 245. This was a mistake introduced into the Meeting template and carried forward. Obviously I missed a few of the pages when I last fixed this. Really you couldn't have gotten too lost, the next building down is a gas station at the corner. -- Scott Sullivan -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 9 15:03:24 2013 From: cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Christopher Browne) Date: Fri, 9 Aug 2013 11:03:24 -0400 Subject: understanding probability In-Reply-To: <5d53f5723ee501235b7aa7efc7176ad7.squirrel-41R2vWz+eC7k1uMJSBkQmQ@public.gmane.org> References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <51FD57D5.60000@rogers.com> <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> Message-ID: On Fri, Aug 9, 2013 at 5:40 AM, Eric B wrote: > To put it more simply, infinity doesn't exist. It's a highly convenient abstraction. Just like having the "C" constant in an indefinite integral; it's not real, but highly, highly useul. >> But, even without infinity, we know that the universe came about from >> nothing. If the universe and everything in it can come from nothing, what >> can be more surprising? > > No one knows that. >>>My concern about the hashing systems is that, in the absence of >>>sufficient analysis, the whole "super-hyper-infinitely-improbable" >>>measures are estimations, and are not certain to be the actuality. > > I share your concern that this is the weakness, but I wouldn't say there > has been insufficient analysis. > >>>And note that in practice, it's eminently difficult to perfectly validate >>>the precise characteristics of the fissile mass, as what you can >>>know about it tends to come out of statistical analysis of observations. >>>(If we knew when atoms were going to decay, well, that's supposed >>>to be the thing we are completely unable to know, isn't it?!?) >>> >>>If I saw too many atoms decaying all at once, I would be keen to >>>head to the hypothesis that we got the model wrong, and imagined >>>that the material was composed rather differently than was truly >>>the case. > > The last thing you should consider is that the physics model is wrong. Hmm. I'd put that pretty high on my list, and there are two perspectives, one of them entirely easier to agree on. The harder one is that "physics is wrong." I note that the place that we get new bits of physics is by coming to the conclusion that the model that we have doesn't correctly express reality. You need to modify Newtonian physics (which are *mostly* nicely expressive of the phenomena we tend to see) when at certain edges one needs to take Relativity into account. Now, there's a pretty big burden of proof required to establish that *everyone* has been getting things wrong and that the deep models need to be changed. The easier one is more about the local interpretation. For the fissile mass, if I see way too many atoms decaying, more than my model of the object would account for, then it seems quite reasonable to think that maybe my model of the particular object is wrong. Perhaps I didn't account for a nearby chunk of Polonium, or something of the sort. I'm not talking about saying "theories of radioactivity are wrong," rather, I *thought* that the situation involved one thing, with one rate of radioactive decay, but reality is somewhere else. >>>Similarly, if I "shuffled" a deck, and then drew 4 aces in a row, I'd >>>be pretty inclined to the hypothesis that this wasn't just random >>>chance, but rather: >>>a) Some exploit in the shuffling system, or >>>b) Perhaps there's more than 4 aces in the deck? >>> >>>And if I saw a bunch of SHA-1 collisions, then either: >>>a) Lotta duplicate things getting hashed, >>>b) Buggy implementation of SHA-1, or >>>c) Something more deeply wrong with SHA-1 >>>are all plausible hypotheses, and it may be quite difficult to >>>distinguish between b) and c), in particular. > > Again, option c) is he least plausible since no one has found a false > collision. Right, but (rather like Newtonian versus General Relativity) there's some point at which b) and c) need to be distinguished. I said it may be difficult to distinguish between them; one should not immediately leap from "Oh, I saw a collision" to "Oh, SHA-1 is utterly broken by design." But the pundits originally thought that MD5 was pretty good, and there has indeed been this sort of shift to thinking that it isn't wise to use MD5 for cryptographically-important tasks anymore because it has some flaws. That sure seems like a precedent of the same sort of thing. Based on the history of hashing algorithms thus far, it seems pretty reasonable to imagine it quite possible that 10 years from now someone may discover significant flaws in SHA-1. That doesn't imply that *my* collision represents a flaw in SHA-1. But I would be careful not to be *too* self-satisfiedly certain that a collision indicates identical data; I'd want to at least consider checking. -- When confronted by a difficult problem, solve it by reducing it to the question, "How would the Lone Ranger handle this?" -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From softquake-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 9 15:30:10 2013 From: softquake-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Zbigniew Koziol) Date: Fri, 09 Aug 2013 19:30:10 +0400 Subject: understanding probability In-Reply-To: References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <51FD57D5.60000@rogers.com> <1375927381.48685.YahooMailNeo@web161903. mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> Message-ID: <52050B02.3030008@gmail.com> On 09/08/13 19:03, Christopher Browne wrote: > On Fri, Aug 9, 2013 at 5:40 AM, Eric B wrote: >> To put it more simply, infinity doesn't exist. > It's a highly convenient abstraction. Just like having the "C" constant in an > indefinite integral; it's not real, but highly, highly useul. I thought about commenting on this earlier. Infinity is just exactly the same abstract concept as 0, minus one, or even digit 1. It exists and does not exists at the same time in exactly the same manner. Or as "number" pi=3.154159256..., or e - the base of natural logarithm, or number sqrt(-1). Or aleph zero. Or as infinity to power of infinity, etc. And there we have for instance such beautiful relations between numbers of which each of them is perfectely abstract: -1 = e^(i*pi) [...] zb. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Fri Aug 9 16:00:10 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Fri, 09 Aug 2013 12:00:10 -0400 Subject: understanding probability In-Reply-To: <5d53f5723ee501235b7aa7efc7176ad7.squirrel-41R2vWz+eC7k1uMJSBkQmQ@public.gmane.org> References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <51FD57D5.60000@rogers.com> <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.n et> Message-ID: <5205120A.8050908@rogers.com> Eric B wrote: > To put it more simply, infinity doesn't exist. How do you know that? Take any integer you can think of. Keep adding 1 or any other integer and let me know when you reach the end. When does time end? Infinite space is certainly a tough concept to swallow, but is it impossible? -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Fri Aug 9 16:02:02 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Fri, 9 Aug 2013 12:02:02 -0400 Subject: understanding probability In-Reply-To: <52050B02.3030008-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> References: <51FB17DD.7090009@rogers.com> <51FD57D5.60000@rogers.com> <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> Message-ID: <20130809160202.GA7306@csclub.uwaterloo.ca> On Fri, Aug 09, 2013 at 07:30:10PM +0400, Zbigniew Koziol wrote: > I thought about commenting on this earlier. > > Infinity is just exactly the same abstract concept as 0, minus one, > or even digit 1. It exists and does not exists at the same time in > exactly the same manner. Or as "number" pi=3.154159256..., or e - > the base of natural logarithm, or number sqrt(-1). Or aleph zero. Or > as infinity to power of infinity, etc. And there we have for > instance such beautiful relations between numbers of which each of > them is perfectely abstract: -1 = e^(i*pi) > [...] Well infinity is NOT a number as such, at least not the way everything else you listed is (well except the aleph ones, which are infinity related). pi is a specific value, as is e and i. Sure they are irrational (or complex in the case of i) but they are still specific numbers. And infitity to the power of infinity makes no sense. Power of isn't defined for things that aren't numbers as far as I know. Sure kids trying to outdo each other in an argument may think it makes sense, but it doesn't. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Fri Aug 9 18:40:04 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Fri, 9 Aug 2013 14:40:04 -0400 (EDT) Subject: numbers [was Re: understanding probability] In-Reply-To: <20130809160202.GA7306-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <51FB17DD.7090009@rogers.com> <51FD57D5.60000@rogers.com> <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> Message-ID: | From: Lennart Sorensen | Well infinity is NOT a number as such, at least not the way everything | else you listed is (well except the aleph ones, which are infinity | related). It depends. The word "number" means slightly different things to different people, usually with a large and useful overlap. Certainly to you (with a math degree) the word has a richer meaning than to the average person. Transfinite numbers include infinities. That's kind of the standard model in math. Not the only model. | pi is a specific value, as is e and i. Sure they are irrational (or | complex in the case of i) but they are still specific numbers. The normal use of the English word "number" is unlikely to include imaginary numbers. If you include them, where do you draw the line? Are surreal numbers numbers? Transfinite numbers? Hypercomplex numbers (eg. quaternions)? | And infitity to the power of infinity makes no sense. In most systems. The way we understand infinities today is dominated by Cantor's approach. It isn't the only consistent version. | Power of isn't | defined for things that aren't numbers as far as I know. In math (not English) one is free to define or redefine whatever you want, at the risk of (a) having difficulty communicating with others, and (b) having a not very useful definition. Unless you are with Plato in thinking that there is one true class "number". Probably not including irrationals. "God made the integers; all else is the work of man." or "God made natural numbers; all else is the work of man" (Kronecker) My view: There are lots of kinds of things that I would classify as numbers. They are a useful abstraction of a bunch of properties of things in the physical (or imagined) world. Manipulating numbers lets us predict or understand properties of things in the physical (or imagined) world. Number isn't in the real world, but it is often about it. I'm rather inclusive with the term number, at least sometimes. I accept lots of groups/rings/fields as sorts of numbers. Like naturals mod 2 or 3 or 18446744073709551616. This is an interesting and classic paper on this topic from a physicist. The title itself has been influential "The Unreasonable Effectiveness of Mathematics in the Natural Sciences". I like this quotation: ... philosophy is the misuse of a terminology which was invented just for this purpose. (Dubislav) -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Fri Aug 9 20:36:24 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Fri, 9 Aug 2013 16:36:24 -0400 Subject: numbers [was Re: understanding probability] In-Reply-To: References: <51FD57D5.60000@rogers.com> <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> Message-ID: <20130809203624.GB7306@csclub.uwaterloo.ca> On Fri, Aug 09, 2013 at 02:40:04PM -0400, D. Hugh Redelmeier wrote: > It depends. The word "number" means slightly different things to > different people, usually with a large and useful overlap. > > Certainly to you (with a math degree) the word has a richer meaning > than to the average person. > > Transfinite numbers include infinities. That's kind of the standard > model in math. Not the only model. > > | pi is a specific value, as is e and i. Sure they are irrational (or > | complex in the case of i) but they are still specific numbers. > > The normal use of the English word "number" is unlikely to include > imaginary numbers. If you include them, where do you draw the line? > Are surreal numbers numbers? Transfinite numbers? Hypercomplex > numbers (eg. quaternions)? If I can do arithmetic with them, they are numbers. That certainly includes i but not infinity. > | And infitity to the power of infinity makes no sense. > > In most systems. > > The way we understand infinities today is dominated by Cantor's > approach. It isn't the only consistent version. What other option is consistent? I guess being the commonly used one, I am used to Cantor's approach. > In math (not English) one is free to define or redefine whatever you > want, at the risk of > (a) having difficulty communicating with others, and > (b) having a not very useful definition. > > Unless you are with Plato in thinking that there is one true class > "number". Probably not including irrationals. > > "God made the integers; all else is the work of man." > or "God made natural numbers; all else is the work of man" > (Kronecker) > > My view: There are lots of kinds of things that I would classify as > numbers. They are a useful abstraction of a bunch of properties of > things in the physical (or imagined) world. Manipulating numbers lets > us predict or understand properties of things in the physical (or > imagined) world. Number isn't in the real world, but it is often > about it. > > I'm rather inclusive with the term number, at least sometimes. I > accept lots of groups/rings/fields as sorts of numbers. Like naturals > mod 2 or 3 or 18446744073709551616. > > This is an interesting and classic paper on this topic from a > physicist. The title itself has been influential "The Unreasonable > Effectiveness of Mathematics in the Natural Sciences". > > > I like this quotation: ... philosophy is the misuse of a terminology which > was invented just for this purpose. (Dubislav) I am not quite sure how to think of groups/rings/fields as numbers. They often consist of numbers though (although they don't have to). -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Sat Aug 10 02:36:09 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Fri, 9 Aug 2013 22:36:09 -0400 (EDT) Subject: [GW-C] Re:numbers [was Re: understanding probability] In-Reply-To: <20130809203624.GB7306-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <51FD57D5.60000@rogers.com> <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> <20130809203624.GB7306@csclub.uwaterloo.ca> Message-ID: | From: Lennart Sorensen | If I can do arithmetic with them, they are numbers. That certainly | includes i but not infinity. For example, you can do arithmetic with matrices: +, -, *, / are defined on them. Are these numbers? (The arithmethic isn't exactly the same as in natural numbers, so it is up to the observer to decide if it counts as real arithmetic to him or her.) IEEE 754 floating point includes infinities. I was surprised to be reminded recently that its infinities are not NaNs (non-a-number). | > | And infitity to the power of infinity makes no sense. | > | > In most systems. | > | > The way we understand infinities today is dominated by Cantor's | > approach. It isn't the only consistent version. | | What other option is consistent? I guess being the commonly used one, | I am used to Cantor's approach. Any system with infinities loses some properties that we assumed were universal. That usually happens whenever you generalize a numeric system. Classic example: complex numbers cannot be ordered in a useful way. One simple version of infinity: just one infinity; any operation on infinity yields infinity. What do we lose: lots of things, for example: x + 1 != x Infinity to the power infinity would then be infinity. | > I'm rather inclusive with the term number, at least sometimes. I | > accept lots of groups/rings/fields as sorts of numbers. Like naturals | > mod 2 or 3 or 18446744073709551616. | I am not quite sure how to think of groups/rings/fields as numbers. | They often consist of numbers though (although they don't have to). "They often consist of numbers" is a pretty strong statement. Do you mean "their elements can be denoted by numerals"? That's more conservative. Essentially, your original statement seems to imply that those groups are numbers. "The price of metaphor is eternal vigilance." (Arturo Rosenblueth and Norbert Wiener) -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From acitta1-YDxpq3io04c at public.gmane.org Sat Aug 10 14:37:17 2013 From: acitta1-YDxpq3io04c at public.gmane.org (Gary Walsh) Date: Sat, 10 Aug 2013 10:37:17 -0400 Subject: Support help needed in Markham Message-ID: <1376145437.5971.4.camel@localhost> Is there anyone on this list in or near the Markham area who can give on site support to someone? There is somebody that I support who has a bootup problem that I can't diagnose remotely. Since I live in Kitchener, it is hard for me to get to his place quickly. Familiarity with Mageia 3 would be helpful. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From gyre-Ja3L+HSX0kI at public.gmane.org Sun Aug 11 06:41:53 2013 From: gyre-Ja3L+HSX0kI at public.gmane.org (Eric) Date: Sun, 11 Aug 2013 02:41:53 -0400 (EDT) Subject: understanding probability In-Reply-To: <5205120A.8050908-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <5205120A.8050908@rogers.com> Message-ID: On Fri, 9 Aug 2013, James Knott wrote: > Eric B wrote: > > To put it more simply, infinity doesn't exist. > > How do you know that? Take any integer you can think of. Keep adding 1 > or any other integer and let me know when you reach the end. When does > time end? Infinite space is certainly a tough concept to swallow, but > is it impossible? Integers do not exist. They are not real objects. They are mental constructs. I don't "know" that infinity doesn't exist; I claim it. It isn't up to me to prove it; it is up to any one making the claim (that infinity exists) to prove it. As it stands, there is no evidence for anything infinite existing. Likewise, I don't know for certain that unicorns don't exist somewhere, but the onus is one the person making the claim to demonstrate it. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Sun Aug 11 12:29:48 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Sun, 11 Aug 2013 08:29:48 -0400 Subject: understanding probability In-Reply-To: References: <5205120A.8050908@rogers.com> Message-ID: <520783BC.60106@rogers.com> Eric wrote: > I don't "know" that infinity doesn't exist; I claim it. > It isn't up to me to prove it; it is up to any one making the > claim (that infinity exists) to prove it. > As it stands, there is no evidence for anything infinite existing. As far as the universe is concerned, so much of it is so far removed from our common experiences, that it's simply impossible to comprehend. It wasn't that long ago, that our galaxy was considered to be the entire universe or that the earth was claimed to be the centre of it. When you get into the possibilities of how things work, possible multiple universes, multiple dimensions, foam and more, not to mention the weirdness at the quantum level, it's best not to claim absolutes, when all you can honestly say is "I don't know". One example of something that was at one time considered to be impossible is quantum tunnelling. However, without it, solid state electronics would be impossible. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Sun Aug 11 18:18:10 2013 From: colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Colin McGregor) Date: Sun, 11 Aug 2013 14:18:10 -0400 Subject: Semi-OT: Why Kids Can't use Computers Message-ID: Ran across this story about why kids can't use computers, and the story has some suggestions as to how to fix that (part of the suggestion being the use of Linux): http://www.coding2learn.org/blog/2013/07/29/kids-cant-use-computers/ Colin McGregor -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From ekg_ab-FFYn/CNdgSA at public.gmane.org Mon Aug 12 01:20:30 2013 From: ekg_ab-FFYn/CNdgSA at public.gmane.org (E K) Date: Sun, 11 Aug 2013 18:20:30 -0700 (PDT) Subject: numbers [was Re: understanding probability] In-Reply-To: <20130809203624.GB7306-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <51FD57D5.60000@rogers.com> <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> <20130809203624.GB7306@csclub.uwaterloo.ca> Message-ID: <1376270430.30822.YahooMailNeo@web161904.mail.bf1.yahoo.com> ----- Original Message ----- > From: Lennart Sorensen > To: tlug-lxSQFCZeNF4 at public.gmane.org > Cc: > Sent: Friday, August 9, 2013 2:36:24 PM > Subject: Re: [TLUG]: numbers [was Re: understanding probability] > > On Fri, Aug 09, 2013 at 02:40:04PM -0400, D. Hugh Redelmeier wrote: >> It depends.? The word "number" means slightly different things to >> different people, usually with a large and useful overlap. >> >> Certainly to you (with a math degree) the word has a richer meaning >> than to the average person. >> >> Transfinite numbers include infinities.? That's kind of the standard >> model in math.? Not the only model. >> >> | pi is a specific value, as is e and i.? Sure they are irrational (or >> | complex in the case of i) but they are still specific numbers. >> >> The normal use of the English word "number" is unlikely to > include >> imaginary numbers.? If you include them, where do you draw the line? >> Are surreal numbers numbers?? Transfinite numbers?? Hypercomplex >> numbers (eg. quaternions)? > > If I can do arithmetic with them, they are numbers.? That certainly > includes i but not infinity. >? Can you do arithmetic with the alephs? What is the arithmetic with them? EK -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org Mon Aug 12 13:31:53 2013 From: jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org (Jamon Camisso) Date: Mon, 12 Aug 2013 09:31:53 -0400 Subject: numbers [was Re: understanding probability] In-Reply-To: <1376270430.30822.YahooMailNeo-/W4/QBBOCLLK0anN2EpufZEhsgyP+Z75VpNB7YpNyf8@public.gmane.org> References: <51FD57D5.60000@rogers.com> <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> <20130809203624.GB7306@csclub.uwaterloo.ca> <1376270430.30822.YahooMailNeo@web161904.mail.bf1.yahoo.com> Message-ID: <5208E3C9.4060904@utoronto.ca> On 11/08/13 09:20 PM, E K wrote: > Can you do arithmetic with the alephs? What is the arithmetic with them? Yes: see Transfinite Cardinal Arithmetic with Wolfram|Alpha http://blog.wolframalpha.com/2010/09/10/transfinite-cardinal-arithmetic-with-wolframalpha/ Jamon -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Mon Aug 12 14:09:16 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Mon, 12 Aug 2013 10:09:16 -0400 Subject: [GW-C] Re:numbers [was Re: understanding probability] In-Reply-To: References: <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> <20130809203624.GB7306@csclub.uwaterloo.ca> Message-ID: <20130812140916.GC7306@csclub.uwaterloo.ca> On Fri, Aug 09, 2013 at 10:36:09PM -0400, D. Hugh Redelmeier wrote: > For example, you can do arithmetic with matrices: +, -, *, / are > defined on them. Are these numbers? (The arithmethic isn't exactly > the same as in natural numbers, so it is up to the observer to decide > if it counts as real arithmetic to him or her.) If the matrices have contents you can do arithmetic on, then you can do it on the matrices too. I am not sure you can multiply two matrices that are full of letters without first defining what it means to multiply letters. > IEEE 754 floating point includes infinities. I was surprised to be > reminded recently that its infinities are not NaNs (non-a-number). Their infinities are still invalid to do calculations with. You can only really use them to compare against (not that that makes that much sense either). > Any system with infinities loses some properties that we assumed were > universal. That usually happens whenever you generalize a numeric > system. Classic example: complex numbers cannot be ordered in a > useful way. Certainly seems that way. I guess you could order them by size, but that still isn't really a useful way to order them. Of course people assume things that are wrong too in many cases. It's interesting to see all the ways of proving 0.999... = 1 and how many people refuse to accept that, while having no issue with 0.333... = 1/3 and 3 * 1/3 = 1, yet 3 * 0.333... = 0.999... doesn't make them accept that it is the same thing. Intuition is often wrong. > One simple version of infinity: just one infinity; any operation on > infinity yields infinity. What do we lose: lots of things, for > example: > x + 1 != x > Infinity to the power infinity would then be infinity. Not very useful, Seems simpler to just not allow doing operations on it. It's a great limit, but not a great number. > "They often consist of numbers" is a pretty strong statement. Do you > mean "their elements can be denoted by numerals"? That's more > conservative. Essentially, your original statement seems to imply > that those groups are numbers. I am sure someone has defined what it should mean. Most groups I have seen have elements that are numbers. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From sciguy-Ja3L+HSX0kI at public.gmane.org Mon Aug 12 17:26:13 2013 From: sciguy-Ja3L+HSX0kI at public.gmane.org (Paul King) Date: Mon, 12 Aug 2013 13:26:13 -0400 Subject: understanding probability In-Reply-To: References: <20130730145758.GI11327@csclub.uwaterloo.ca> <20130730192543.GN11327@csclub.uwaterloo.ca> <99941996b91f7e060d4a0227e6e30e3f.squirrel@mail.vex.net> <51F86443.90206@rogers.com> <51FB17DD.7090009@rogers.com> <51FD57D5.60000@rogers.com> <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> Message-ID: <000001ce9781$14fca4c0$3ef5ee40$@net> > On Fri, Aug 9, 2013 at 5:40 AM, Christopher Browne wrote: > The harder one is that "physics is wrong." I note that the place that > we get new bits of physics is by coming to the conclusion that the > model that we have doesn't correctly express reality. You need to > modify Newtonian physics (which are *mostly* nicely expressive of the > phenomena we tend to see) when at certain edges one needs to take > Relativity into account. Now, there's a pretty big burden of proof > required to establish that *everyone* has been getting things wrong and > that the deep models need to be changed. Actually, the way I teach physics is to say that Quantum Mechanics is the "correct" theory, while still saying that Newtonian mechanics works well at the macroscopic level. That is, classical mechanics needs no modification for what it does. We can still use it to build our bridges and skyscrapers. It just wouldn't be used to explain what goes on inside a silicon chip. Or most of the most useful reaction mechanisms of biochemistry would also not have good explanations. So, technically, Newtonian Physics, in its promise to explain the world, couldn't do it unless you excluded those things beyond the fringes of our sense of reality, like black holes and atoms. Since it failed to do so, quantum mechanics claims to cover everything this time. But using its equations to build bridges or skyscrapers is unnecessarily complicated, so the simpler equations of classical mechanics serve just nicely. > > The easier one is more about the local interpretation. For the fissile > mass, if I see way too many atoms decaying, more than my model of the > object would account for, then it seems quite reasonable to think that > maybe my model of the particular object is wrong. Perhaps I didn't > account for a nearby chunk of Polonium, or something of the sort. I'm > not talking about saying "theories of radioactivity are wrong," rather, > I *thought* that the situation involved one thing, with one rate of > radioactive decay, but reality is somewhere else. > It could be that your conjecture is wrong, but Quantum mechanics is a probabilistic model, so there is nothing saying that in the next 60 seconds, the small percentage of radioactive isotopes in your body of Carbon, Hydrogen, Oxygen, Phosphorus, Nitrogen and so on will not all emit a beta particles in that time. That likelihood is extremely remote, but it still stands as a likelihood. A probability. Like the probability of 100 monkeys typing out a Shakespearean sonnet by hacking the letters at random. Might not happen, but it could. Four aces dealt once would only surprise me, but if it happened two or more times in a row, that might make me suspicious. > > But the pundits originally thought that MD5 was pretty good, and there > has indeed been this sort of shift to thinking that it isn't wise to > use MD5 for cryptographically-important tasks anymore because it has > some flaws. That sure seems like a precedent of the same sort of > thing. > > Based on the history of hashing algorithms thus far, it seems pretty > reasonable to imagine it quite possible that 10 years from now someone > may discover significant flaws in SHA-1. That doesn't imply that *my* > collision represents a flaw in SHA-1. > > But I would be careful not to be *too* self-satisfiedly certain that a > collision indicates identical data; I'd want to at least consider > checking. > -- > When confronted by a difficult problem, solve it by reducing it to the > question, "How would the Lone Ranger handle this?" > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to > UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Mon Aug 12 17:51:19 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Mon, 12 Aug 2013 13:51:19 -0400 (EDT) Subject: numbers [was Re: understanding probability] In-Reply-To: <5208E3C9.4060904-H217xnMUJC0sA/PxXw9srA@public.gmane.org> References: <51FD57D5.60000@rogers.com> <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> <20130809203624.GB7306@csclub.uwaterloo.ca> <1376270430.30822.YahooMailNeo@web161904.mail.bf1.yahoo.com> <5208E3C9.4060904@utoronto.ca> Message-ID: | From: Jamon Camisso | Yes: see Transfinite Cardinal Arithmetic with Wolfram|Alpha | | http://blog.wolframalpha.com/2010/09/10/transfinite-cardinal-arithmetic-with-wolframalpha/ Nice, easy article. I always thought that aleph-sub-0 was pronounced "aleph-null", not "aleph-zero". Maybe that's old school. " Kurt G?del showed that the known axioms of mathematics are insufficient to disprove the hypothesis. This seemed tantalizingly close to a proof of the continuum hypothesis, but then in 1963, Paul Cohen showed that the known axioms are also insufficient to prove the continuum hypothesis. In other words, the known facts of mathematics are simply not sufficient to answer Cantor?s question." The summary seems wrong-headed. Axioms are not well described as "the known facts". They are the postulates, the only givens, the starting point. So we cannot discover anything to prove or disprove the continuum hypothesis. Finding a distinct number between aleph-0 and beth-1 would constitute a disproof. So it is clear that we cannot find such a number. So looking is pointless. There are three paths forward, and they can all be pursued (I think they are): (a) work with the (original) system in which the continuum hypothesis is unresolveable. Most useful work doesn't care. (b) create a new system with an added axiom equivalent to the continuum hypothesis and work with that. I think that that is fairly common. (c) create a new system with an added axiom equivalent to the opposite of the continuum hypothesis and work with that. I don't think that this is common. Mathematicians generally work in (a) since almost any result they prove in (a) is true in (b) and (c) as well. Of course you can prove in (a) and not in (b) or (c) that you cannot prove or disprove the continuum hypothesis, so not every result carries over. When mathematicians need the continuum hypothesis for some proof, they work in (b). I don't think (c) has a rich a set of results for harvesting. From sciguy-Ja3L+HSX0kI at public.gmane.org Mon Aug 12 18:00:48 2013 From: sciguy-Ja3L+HSX0kI at public.gmane.org (Paul King) Date: Mon, 12 Aug 2013 14:00:48 -0400 Subject: [GW-C] Re:numbers [was Re: understanding probability] In-Reply-To: <20130812140916.GC7306-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> <20130809203624.GB7306@csclub.uwaterloo.ca> <20130812140916.GC7306@csclub.uwaterloo.ca> Message-ID: <000401ce9785$e0b22960$a2167c20$@net> > Of course people assume things that are wrong too in many cases. > It's interesting to see all the ways of proving 0.999... = 1 and how > many people refuse to accept that, while having no issue with 0.333... > = > 1/3 and 3 * 1/3 = 1, yet 3 * 0.333... = 0.999... doesn't make them > accept that it is the same thing. Intuition is often wrong. > See a video on this topic posted as an April Fool's joke: http://www.youtube.com/watch?v=wsOXvQn3JuE Paul -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From softquake-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Mon Aug 12 18:42:12 2013 From: softquake-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Zbigniew Koziol) Date: Mon, 12 Aug 2013 22:42:12 +0400 Subject: understanding probability In-Reply-To: <000401ce9785$e0b22960$a2167c20$@net> References: <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> <20130809203624.GB7306@csclub.uwaterloo.ca> <20130812140916.GC7306@csclub.uwaterloo.ca> <000401ce9785$e0b22960$a2167c20$@net> Message-ID: <52092C84.30407@gmail.com> I had some argument with my Russian wife. About logic. Wife is a farmacist. This is of course a sort of profession. She earns 3 times more that I am at university ;) Lennart is a marerialist. I am too. Though I will rarely agree with him on numbers ;) You do not need to understand words, but music and feelings. Anna German(*). This is not well known. The performance is based on Lermontov poetry. (*) Anna German was born in Uzbekistan. She died of a sort of cancer in around 1982 (find yourself). She was not Polish, and not Russian, but these countries consider her as she was. She was of ... father from Polish city of ??d?, who was not Polish but.. rather from Holland. And mother who was.. name was Irma, certainly not Polish. http://www.youtube.com/watch?v=Bl9VDbRwOxo -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Mon Aug 12 19:54:05 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Mon, 12 Aug 2013 15:54:05 -0400 (EDT) Subject: [GW-C] Re:numbers [was Re: understanding probability] In-Reply-To: <20130812140916.GC7306-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> <20130809203624.GB7306@csclub.uwaterloo.ca> <20130812140916.GC7306@csclub.uwaterloo.ca> Message-ID: | From: Lennart Sorensen | If the matrices have contents you can do arithmetic on, then you can do it | on the matrices too. As explicitly as I can say it: - what does "arithmetic" mean to you? - what does "number" mean to you? Surely your answer should be with respect to an algebraic ofject having elements and operators on those elements. Just talking about operators and not elements or elements and not operators cannot be rigorous enough to make your meaning clear and specific. | I am not sure you can multiply two matrices that are | full of letters without first defining what it means to multiply letters. Letters? Do you mean formal variables, as in polynomials? Or as elements in an algebra? | > IEEE 754 floating point includes infinities. I was surprised to be | > reminded recently that its infinities are not NaNs (non-a-number). | | Their infinities are still invalid to do calculations with. You can | only really use them to compare against (not that that makes that much | sense either). The brains behind 754, William Kahan, certainly had clear (and complicated) ideas behind these infinities. He had plenty of uses for them. I've always thought that he wanted too many properties from numerical hardware and elementary functions, overconstraining the implementation. But his talks are pretty entertaining and convincing. Amazing (to me) story about Kahan. He showed that the original IBM/360 floating point hardware specifications yielded significantly lower precision than could be achieved. IBM took his advice and changed the specs and retrofitted a "guard digit" into every /360 in the field! This was not a trivial reflash-the-firmware kind of thing. It must have cost a fortune. | Not very useful, Seems simpler to just not allow doing operations on it. | It's a great limit, but not a great number. If I remember correctly, Kahan wanted infinities so that he could safely write strraight-line code for (for example) elementary operations. Eliminating conditionals makes the code simpler and faster. | > "They often consist of numbers" is a pretty strong statement. Do you | > mean "their elements can be denoted by numerals"? That's more | > conservative. Essentially, your original statement seems to imply | > that those groups are numbers. | | I am sure someone has defined what it should mean. Most groups I have | seen have elements that are numbers. Are the elments of Z mod (2) numbers? Or are the elements the same as (isomorphic to) Heads and Tails, or Naughts and Crosses, or... It's not reasonable to say that a number is anything written down using only digits. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Mon Aug 12 21:03:44 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Mon, 12 Aug 2013 17:03:44 -0400 Subject: understanding probability In-Reply-To: <52092C84.30407-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> References: <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> <20130809203624.GB7306@csclub.uwaterloo.ca> <20130812140916.GC7306@csclub.uwaterloo.ca> <000401ce9785$e0b22960$a2167c20$@net> <52092C84.30407@gmail.com> Message-ID: <20130812210344.GD7306@csclub.uwaterloo.ca> On Mon, Aug 12, 2013 at 10:42:12PM +0400, Zbigniew Koziol wrote: > I had some argument with my Russian wife. About logic. Wife is a > farmacist. This is of course a sort of profession. She earns 3 times > more that I am at university ;) Some CEOs "earn" hundreds of million a year. That doesn't mean they have a clue about everything. Doesn't mean they don't either. > Lennart is a marerialist. I am too. Though I will rarely agree with > him on numbers ;) I may have a degree that says B.Math on it, but I won't claim to be a mathematician (It does say Computer Science on the degree as well, so clearly I was aimed at more practical stuff). I am entirely able to be wrong about numbers. :) > You do not need to understand words, but music and feelings. Anna > German(*). This is not well known. The performance is based on > Lermontov poetry. > > (*) Anna German was born in Uzbekistan. She died of a sort of cancer > in around 1982 (find yourself). She was not Polish, and not Russian, > but these countries consider her as she was. She was of ... father > from Polish city of ??d?, who was not Polish but.. rather from > Holland. And mother who was.. name was Irma, certainly not Polish. > > http://www.youtube.com/watch?v=Bl9VDbRwOxo -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From sciguy-Ja3L+HSX0kI at public.gmane.org Mon Aug 12 21:12:23 2013 From: sciguy-Ja3L+HSX0kI at public.gmane.org (Paul King) Date: Mon, 12 Aug 2013 17:12:23 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: References: Message-ID: <000901ce97a0$a50039a0$ef00ace0$@net> I also am sick of this baseless stereotype being bandied about with my colleagues at school that kids "know more" about computers than adults. They are at least equally ignorant with twice the gadgets. I have also seen this firsthand when teaching computer science that 1) their level of (general) literacy does not go much past the 140 character limit of a Twitter message, and 2) their level of computer literacy does not go much past knowing how to get a lolcat YouTube video to run on their Androids. However, there are always exceptions, exactly as the author suggested. "There are one or two [students] in every cohort that can" replace motherboards and operating systems. "Cohort" means the entire grade in the whole school. I think that is a realistic ratio of literacy-to-ignorance in most schools in Canada also. It would be a challenging enough question for most colleagues as well as students to just get them to distinguish between "the internet" and "the world-wide web". Members of Parliament not making this distinction are also writing policy on "the internet", and allowing private power to figure out what that means. The only noticeable success in the past 20 years of the "digital revolution" is in the amount of money made by tech companies with something to sell to the under-18 demographic. What we really have are a generation of un-informed consumers of digital products who don't know and don't care about news events like Snowden and the NSA, among a whole raft of other things. Un-informed consumers who don't know their rights and freedoms are easy to sell to and easy to dupe. The "shut up and buy" mantra is built-in, since they are ignorant to begin with. For the record, I don't currently teach computer science. I teach math. Paul King -----Original Message----- From: owner-tlug-lxSQFCZeNF4 at public.gmane.org [mailto:owner-tlug-lxSQFCZeNF4 at public.gmane.org] On Behalf Of Colin McGregor Sent: Sunday, August 11, 2013 2:18 PM To: tlug Subject: [TLUG]: Semi-OT: Why Kids Can't use Computers Ran across this story about why kids can't use computers, and the story has some suggestions as to how to fix that (part of the suggestion being the use of Linux): http://www.coding2learn.org/blog/2013/07/29/kids-cant-use-computers/ Colin McGregor -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Mon Aug 12 21:18:25 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Mon, 12 Aug 2013 17:18:25 -0400 Subject: [GW-C] Re:numbers [was Re: understanding probability] In-Reply-To: References: <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> <20130809203624.GB7306@csclub.uwaterloo.ca> <20130812140916.GC7306@csclub.uwaterloo.ca> Message-ID: <20130812211825.GE7306@csclub.uwaterloo.ca> On Mon, Aug 12, 2013 at 03:54:05PM -0400, D. Hugh Redelmeier wrote: > As explicitly as I can say it: > > - what does "arithmetic" mean to you? > > - what does "number" mean to you? > > Surely your answer should be with respect to an algebraic ofject > having elements and operators on those elements. Just talking about > operators and not elements or elements and not operators cannot be > rigorous enough to make your meaning clear and specific. Well it does all come down to your defined system in the end. > Letters? Do you mean formal variables, as in polynomials? Or as > elements in an algebra? I was thinking of them as values, nor variables. > The brains behind 754, William Kahan, certainly had clear (and > complicated) ideas behind these infinities. He had plenty of uses for > them. I've always thought that he wanted too many properties from > numerical hardware and elementary functions, overconstraining the > implementation. But his talks are pretty entertaining and convincing. > > Amazing (to me) story about Kahan. He showed that the original > IBM/360 floating point hardware specifications yielded significantly > lower precision than could be achieved. IBM took his advice and > changed the specs and retrofitted a "guard digit" into every /360 in > the field! This was not a trivial reflash-the-firmware kind of thing. > It must have cost a fortune. Well there probably weren't that many machines, and if they were microcoded then if that microcode was changeable, then it probably wouldn't be that costly. Even if it involved hardware swaps, the development cost for the machines was probably much larger than the actual chip manufacturing costs, so again perhaps not that bad. > If I remember correctly, Kahan wanted infinities so that he could > safely write strraight-line code for (for example) elementary > operations. Eliminating conditionals makes the code simpler and > faster. That sounds fair enough. > Are the elments of Z mod (2) numbers? Or are the elements the same as > (isomorphic to) Heads and Tails, or Naughts and Crosses, or... > > It's not reasonable to say that a number is anything written down > using only digits. Depends on what you consider digits. After all hex uses a-f as digits too but perfectly well defined meanings. Of course as long as your operations are defined, your numbers could be anything. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Tue Aug 13 01:38:01 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Mon, 12 Aug 2013 21:38:01 -0400 (EDT) Subject: numbers [was Re: understanding probability] In-Reply-To: <20130812211825.GE7306-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> <20130809203624.GB7306@csclub.uwaterloo.ca> <20130812140916.GC7306@csclub.uwaterloo.ca> <20130812211825.GE7306@csclub.uwaterloo.ca> Message-ID: | From: Lennart Sorensen | On Mon, Aug 12, 2013 at 03:54:05PM -0400, D. Hugh Redelmeier wrote: | > Amazing (to me) story about Kahan. He showed that the original | > IBM/360 floating point hardware specifications yielded significantly | > lower precision than could be achieved. IBM took his advice and | > changed the specs and retrofitted a "guard digit" into every /360 in | > the field! This was not a trivial reflash-the-firmware kind of thing. | > It must have cost a fortune. | | Well there probably weren't that many machines, and if they were | microcoded then if that microcode was changeable, then it probably | wouldn't be that costly. Even if it involved hardware swaps, the | development cost for the machines was probably much larger than the | actual chip manufacturing costs, so again perhaps not that bad. - I think that they did do it early enough that there were not an overwhelming number of machines in the field. - there were a half dozen different implementations of the architecture, and each needed to be fixed. Most, but not all, were microcoded. I think that each model used a different microcode store (CROS for the 30, TROS for the 40, and I don't know the others). - I think that the FP instructions slowed down on the one I used (the model 75 in University of Waterloo). My understanding was that another pass through the ALU was required to match the new specs: it wasn't feasible to change its width. - /360 machines were not made of integrated circuits. They had potted units with a small number of discrete compunents. The /360 had some interesting characteristics. IBM famously "bet the company" on it, and won big. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From ekg_ab-FFYn/CNdgSA at public.gmane.org Tue Aug 13 01:38:18 2013 From: ekg_ab-FFYn/CNdgSA at public.gmane.org (E K) Date: Mon, 12 Aug 2013 18:38:18 -0700 (PDT) Subject: numbers [was Re: understanding probability] In-Reply-To: <5208E3C9.4060904-H217xnMUJC0sA/PxXw9srA@public.gmane.org> References: <51FD57D5.60000@rogers.com> <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> <20130809203624.GB7306@csclub.uwaterloo.ca> <1376270430.30822.YahooMailNeo@web161904.mail.bf1.yahoo.com> <5208E3C9.4060904@utoronto.ca> Message-ID: <1376357898.71668.YahooMailNeo@web161901.mail.bf1.yahoo.com> That is not arithmetic. The addition in there doesn't have identity, it doesn't have inverse? Addition and multiplication are the same and simply return the largest number. You might as well define that kind of "arithmetic" over any ordered set. For example, over students in a class, like ? ? ? ? Mark + Julie = Mark,?Angelina + Jessica = Jessica? EK ----- Original Message ----- > From: Jamon Camisso > To: tlug-lxSQFCZeNF4 at public.gmane.org > Cc: > Sent: Monday, August 12, 2013 7:31:53 AM > Subject: Re: [TLUG]: numbers [was Re: understanding probability] > > On 11/08/13 09:20 PM, E K wrote: >> Can you do arithmetic with the alephs? What is the arithmetic with them? > > Yes: see Transfinite Cardinal Arithmetic with Wolfram|Alpha > > http://blog.wolframalpha.com/2010/09/10/transfinite-cardinal-arithmetic-with-wolframalpha/ > > Jamon > > -- > The Toronto Linux Users Group.? ? ? Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Tue Aug 13 02:00:04 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Mon, 12 Aug 2013 22:00:04 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <000901ce97a0$a50039a0$ef00ace0$@net> References: <000901ce97a0$a50039a0$ef00ace0$@net> Message-ID: <52099324.1020205@rogers.com> Paul King wrote: > For the record, I don't currently teach computer science. I teach math. Way back when I was in grade 12, I took a Fortran class that was taught by a math teacher. It soon became apparent he didn't know much more about it than we did. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Tue Aug 13 05:03:40 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Tue, 13 Aug 2013 01:03:40 -0400 (EDT) Subject: slightly tricky way of capturing additions to a logfile Message-ID: Background (can be skipped): I'm having problems with grub. Ubuntu has a bug where it won't add grub entries for other installed linuxes UNLESS their /boot is mounted. The fix is upstream (debian) for six months or so but they haven't shipped it (althuogh it is marked as "fix-released"): Fedora had a similar bug. They wouldn't add grub entries for other installed Linuxes unless the partition with /boot had SELinux security labels. Rather a rude requirement considering those labels don't do Ubuntu any good. That one has been fixed: So I found a similar-looking bug in Fedora-19 on the weekend and misdiagnosed it I don't yet know what the bug is. The Red hat maintainer(?) asked me to run os-prober, the thing that is supposed to find other operating systems when generating a grub config file (unless grubby is being used). He wanted to see what was logged to /var/log/messages Foreground: Here are the slightly tricky shell commands I used: [root at redcherry-mimosa-com hugh]# exec {log}/dev/null [root at redcherry-mimosa-com hugh]# cat <&${log} [root at redcherry-mimosa-com hugh]# os-prober /dev/sda1:FreeDOS:FreeDOS:chain [root at redcherry-mimosa-com hugh]# cat <&${log} ... (all the newly added stuff appeared.) How this worked: exec {log}/dev/null this reads everything from that file descriptor and throws it away. cat <&${log} This just shows that there is nothing remaining. os-prober This runs the command that might produce interesting log output. cat <&${log} This command cats all that has been added to the log since the last one. NOTE: this will fail if log rotation occurs at an inconvenient time. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From waltdnes-SLHPyeZ9y/tg9hUCZPvPmw at public.gmane.org Tue Aug 13 06:30:55 2013 From: waltdnes-SLHPyeZ9y/tg9hUCZPvPmw at public.gmane.org (Walter Dnes) Date: Tue, 13 Aug 2013 02:30:55 -0400 Subject: How do I make Lensfun work inside Gimp/Ufraw automatically? Message-ID: <20130813063055.GA6463@waltdnes.org> I posted sample images in a thread at http://www.dpreview.com/forums/post/51971607 showing the distortion in the raw file. There's a posting at http://www.gerhard.fr/DAM/lensfun.php which lists parameters for the Canon S100. I followed the instructions, but it doesn't do anything. Is there an additional step to "register" the specs with Gimp/Ufraw? -- Walter Dnes I don't run "desktop environments"; I run useful applications -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Tue Aug 13 12:32:11 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Tue, 13 Aug 2013 08:32:11 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: References: Message-ID: <520A274B.1030100@rogers.com> Colin McGregor wrote: > Ran across this story about why kids can't use computers, and the > story has some suggestions as to how to fix that (part of the > suggestion being the use of Linux): > > http://www.coding2learn.org/blog/2013/07/29/kids-cant-use-computers/ > My first computer was an IMSAI 8080. It came as a bag of parts and bare circuit boards. I had to assemble everything and then, having done that, I had to start writing software. I knew that computer inside out. I even designed and built an 8 port serial I/O card for it that used only 1 interrupt line for all ports. Those who struggled with IRQs on the PCs would certainly appreciate that. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From mike.kallies-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Tue Aug 13 14:48:54 2013 From: mike.kallies-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Mike Kallies) Date: Tue, 13 Aug 2013 10:48:54 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <000901ce97a0$a50039a0$ef00ace0$@net> References: <000901ce97a0$a50039a0$ef00ace0$@net> Message-ID: <520A4756.2090307@gmail.com> On 12/08/2013 5:12 PM, Paul King wrote: ... > always exceptions, exactly as the author suggested. "There are one or two > [students] in every cohort that can" replace motherboards and operating > systems. "Cohort" means the entire grade in the whole school. I think that > is a realistic ratio of literacy-to-ignorance in most schools in Canada > also. > I bet as a teacher, you've met a handful of students who are keenly interested in math. You point them to the relevant material and they excel beyond it with minimal guidance. They spend time looking up deeper problems and hacking at them, showing you stuff that surprises you and makes you go back to your own textbooks to fully understand. The rest of the students need to be assigned exercises, and if not for math being a prerequisite for whatever they need to do in life, they'd never learn the subject. Not that they dislike it. They might find it interesting, or fun, but when class is over or the assignment is done, they're not speaking the language, innovating, applying or following what's happening on math forums or in the community. OTOH, probably everyone on this list was dumpster diving and ripping apart old machines to build anything and everything we could. We've hacked, programmed, tweaked, read, had meetups and social functions, travelled, done everything we could to learn more. If a kid doesn't have the passion to continue on their own? I don't know what can be done about that, or if anything should be done. They learned some stuff, had fun, decided it didn't compel them, then moved on. -Mike -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Tue Aug 13 14:59:11 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Tue, 13 Aug 2013 10:59:11 -0400 (EDT) Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <520A274B.1030100-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <520A274B.1030100@rogers.com> Message-ID: | From: James Knott | Colin McGregor wrote: | > http://www.coding2learn.org/blog/2013/07/29/kids-cant-use-computers/ | My first computer was an IMSAI 8080. It came as a bag of parts and bare | circuit boards. Sure. And folks who assembled their own kit computers were a tiny minority, even smaller than the percentage of today's cohort who are technically competent according to the article. - putting the bars higher (as they were originally) eliminates a lot of casual users and many potentially good ones. - things in the Good Old Days were a lot simpler and could be mastered. Any sufficiently advanced technology is indistinguisahble from magic. So users are essentially prevented from deep understanding. - we cannot go back (globally). There are attempts (locally): hacklabs, the maker movement, Raspberry Pi. But those seem a bit like toys to most folks. "Real" stuff comes from corporations and pros. It is progress, but I don't like all the side-effects (dis-empowerment and ignorance). I guess that the wild west must be somewhere else. Perhaps 3d printing. Or mobile phone apps. Some technology that is new enough that it hasn't been saturated and yet has got down to a scale where an individual has a chance of contributing. I do agree that programming is a fundamental kind of knowledge, like arithmetic. Citizens ought to understand it. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From rjonasz-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Tue Aug 13 15:04:03 2013 From: rjonasz-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Randy Jonasz) Date: Tue, 13 Aug 2013 11:04:03 -0400 Subject: slightly tricky way of capturing additions to a logfile In-Reply-To: References: Message-ID: On Tue, Aug 13, 2013 at 1:03 AM, D. Hugh Redelmeier wrote: > Background (can be skipped): > > I'm having problems with grub. > > Ubuntu has a bug where it won't add grub entries for other installed > linuxes UNLESS their /boot is mounted. The fix is upstream (debian) > for six months or so but they haven't shipped it (althuogh it is > marked as "fix-released"): > > > Fedora had a similar bug. They wouldn't add grub entries for other > installed Linuxes unless the partition with /boot had SELinux security > labels. Rather a rude requirement considering those labels don't do > Ubuntu any good. That one has been fixed: > > > So I found a similar-looking bug in Fedora-19 on the weekend and > misdiagnosed it > I don't yet know what the bug is. > > The Red hat maintainer(?) asked me to run os-prober, the thing that is > supposed to find other operating systems when generating a grub config > file (unless grubby is being used). He wanted to see what was logged > to /var/log/messages > > > Foreground: > > Here are the slightly tricky shell commands I used: > > [root at redcherry-mimosa-com hugh]# exec {log} [root at redcherry-mimosa-com hugh]# cat <&${log} >/dev/null > [root at redcherry-mimosa-com hugh]# cat <&${log} > [root at redcherry-mimosa-com hugh]# os-prober > /dev/sda1:FreeDOS:FreeDOS:chain > [root at redcherry-mimosa-com hugh]# cat <&${log} Interesting. But I get the following error when trying these commands: root at Nietzsche:/home/rjonasz# exec &{log}< /var/log/syslog [1] 5980 [1]+ Done exec root at Nietzsche:/home/rjonasz# cat <&${log} >/dev/null bash: ${log}: ambiguous redirect [1]+ Stopped cat root at Nietzsche:/home/rjonasz# cat <&"${log}" >/dev/null bash: "${log}": Bad file descriptor Randy -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Tue Aug 13 17:50:45 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Tue, 13 Aug 2013 13:50:45 -0400 Subject: numbers [was Re: understanding probability] In-Reply-To: <1376357898.71668.YahooMailNeo-/W4/QBBOCLJal3a5i+KC+JEhsgyP+Z75VpNB7YpNyf8@public.gmane.org> References: <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> <20130809203624.GB7306@csclub.uwaterloo.ca> <1376270430.30822.YahooMailNeo@web161904.mail.bf1.yahoo.com> <5208E3C9.4060904@utoronto.ca> <1376357898.71668.YahooMailNeo@web161901.mail.bf1.yahoo.com> Message-ID: <20130813175045.GF7306@csclub.uwaterloo.ca> On Mon, Aug 12, 2013 at 06:38:18PM -0700, E K wrote: > That is not arithmetic. The addition in there doesn't have identity, it doesn't have inverse? Addition and multiplication are the same and simply return the largest number. > > You might as well define that kind of "arithmetic" over any ordered set. For example, over students in a class, like > ? ? ? ? Mark + Julie = Mark,?Angelina + Jessica = Jessica? I don't see anywhere that they actually gave answers to the input. They give "simplified" form, but that doesn't mean it is the solution to the stated problem. So far it still looks like you can't do arithmetic on aleph things and infinities. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Tue Aug 13 17:53:48 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Tue, 13 Aug 2013 13:53:48 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <52099324.1020205-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> Message-ID: <20130813175348.GG7306@csclub.uwaterloo.ca> On Mon, Aug 12, 2013 at 10:00:04PM -0400, James Knott wrote: > Way back when I was in grade 12, I took a Fortran class that was taught > by a math teacher. It soon became apparent he didn't know much more > about it than we did. Well some people are bad teachers. It does seem that highschools don't generally have much luck attracting teachers that actually know how to teach programming. At least I haven't encountered any yet. I suspect most of those that could teach programming are either teaching at college or university, or actually programming for a living instead. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Tue Aug 13 17:59:49 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Tue, 13 Aug 2013 13:59:49 -0400 Subject: slightly tricky way of capturing additions to a logfile In-Reply-To: References: Message-ID: <20130813175949.GH7306@csclub.uwaterloo.ca> On Tue, Aug 13, 2013 at 11:04:03AM -0400, Randy Jonasz wrote: > Interesting. But I get the following error when trying these commands: > > root at Nietzsche:/home/rjonasz# exec &{log}< /var/log/syslog > [1] 5980 > [1]+ Done exec > > root at Nietzsche:/home/rjonasz# cat <&${log} >/dev/null > bash: ${log}: ambiguous redirect > > [1]+ Stopped cat > root at Nietzsche:/home/rjonasz# cat <&"${log}" >/dev/null > bash: "${log}": Bad file descriptor Does this do anything you don't get from 'tail -F -n 0 /var/log/syslog'? Of course using tail solves the log rotate problem too. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Tue Aug 13 18:14:07 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Tue, 13 Aug 2013 14:14:07 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <20130813175348.GG7306-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> Message-ID: <520A776F.9010606@rogers.com> Lennart Sorensen wrote: > Well some people are bad teachers. > > It does seem that highschools don't generally have much luck attracting > teachers that actually know how to teach programming. At least I haven't > encountered any yet. I suspect most of those that could teach programming > are either teaching at college or university, or actually programming > for a living instead. Those that can, do. Those that can't, teach. ;-) Actually, he was OK as a math teacher. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Tue Aug 13 19:18:08 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Tue, 13 Aug 2013 15:18:08 -0400 (EDT) Subject: slightly tricky way of capturing additions to a logfile In-Reply-To: References: Message-ID: | From: Randy Jonasz | On Tue, Aug 13, 2013 at 1:03 AM, D. Hugh Redelmeier wrote: | > [root at redcherry-mimosa-com hugh]# exec {log} [root at redcherry-mimosa-com hugh]# cat <&${log} >/dev/null | > [root at redcherry-mimosa-com hugh]# cat <&${log} | > [root at redcherry-mimosa-com hugh]# os-prober | > /dev/sda1:FreeDOS:FreeDOS:chain | > [root at redcherry-mimosa-com hugh]# cat <&${log} | | Interesting. But I get the following error when trying these commands: | | root at Nietzsche:/home/rjonasz# exec &{log}< /var/log/syslog | [1] 5980 | [1]+ Done exec You put in an & which changes everything. It forked a new process! And it fails to initialize $log. | root at Nietzsche:/home/rjonasz# cat <&${log} >/dev/null | bash: ${log}: ambiguous redirect | | [1]+ Stopped cat You now reference an undefined shell variable (log), so this expands to cat <& >/dev/null Which not only doesn't do what you want, but forks again. | root at Nietzsche:/home/rjonasz# cat <&"${log}" >/dev/null | bash: "${log}": Bad file descriptor $log is still not defined. Interesting how the quoting changed the shell's interpretation. Lessons: - it is hard to get unfamiliar and tricky notation exactly right - the shell doesn't give diagnostics that are clear to mortals - "set -u" ought to be the default. With that option, references to undefined shell variables are treated as errors rather than being expanded to the empty string. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Tue Aug 13 19:23:53 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Tue, 13 Aug 2013 15:23:53 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <520A776F.9010606-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <520A776F.9010606@rogers.com> Message-ID: <20130813192353.GI7306@csclub.uwaterloo.ca> On Tue, Aug 13, 2013 at 02:14:07PM -0400, James Knott wrote: > Those that can, do. Those that can't, teach. ;-) > > Actually, he was OK as a math teacher. Very likely. We seem to have had more time to develop teachers for math than computers. :) -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Tue Aug 13 19:26:46 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Tue, 13 Aug 2013 15:26:46 -0400 (EDT) Subject: numbers [was Re: understanding probability] In-Reply-To: <20130813175045.GF7306-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <1375927381.48685.YahooMailNeo@web161903.mail.bf1.yahoo.com> <5d53f5723ee501235b7aa7efc7176ad7.squirrel@mail.vex.net> <52050B02.3030008@gmail.com> <20130809160202.GA7306@csclub.uwaterloo.ca> <20130809203624.GB7306@csclub.uwaterloo.ca> <1376270430.30822.YahooMailNeo@web161904.mail.bf1.yahoo.com> <5208E3C9.4060904@utoronto.ca> <1376357898.71668.YahooMailNeo@web161901.mail.bf1.yahoo.com> <20130813175045.GF7306@csclub.uwaterloo.ca> Message-ID: | From: Lennart Sorensen | I don't see anywhere that they actually gave answers to the input. | They give "simplified" form, but that doesn't mean it is the solution | to the stated problem. | | So far it still looks like you can't do arithmetic on aleph things | and infinities. If alephs are numbers, then they are giving answers. The question still on the table is: are alephs numbers. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From rjonasz-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Tue Aug 13 20:55:34 2013 From: rjonasz-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Randy Jonasz) Date: Tue, 13 Aug 2013 16:55:34 -0400 Subject: slightly tricky way of capturing additions to a logfile In-Reply-To: <20130813175949.GH7306-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130813175949.GH7306@csclub.uwaterloo.ca> Message-ID: > > Does this do anything you don't get from 'tail -F -n 0 /var/log/syslog'? > Of course using tail solves the log rotate problem too. I much prefer this. Easy to remember and it works. Although you need two shells but in most cases that is not a problem. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From rjonasz-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Tue Aug 13 20:57:32 2013 From: rjonasz-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Randy Jonasz) Date: Tue, 13 Aug 2013 16:57:32 -0400 Subject: slightly tricky way of capturing additions to a logfile In-Reply-To: References: Message-ID: On Tue, Aug 13, 2013 at 3:18 PM, D. Hugh Redelmeier wrote: > You put in an & which changes everything. It forked a new process! > And it fails to initialize $log. > Ahah! Stupid typo. It works for me now. Thanks! Randy -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From waltdnes-SLHPyeZ9y/tg9hUCZPvPmw at public.gmane.org Wed Aug 14 04:37:29 2013 From: waltdnes-SLHPyeZ9y/tg9hUCZPvPmw at public.gmane.org (Walter Dnes) Date: Wed, 14 Aug 2013 00:37:29 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <20130813192353.GI7306-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <520A776F.9010606@rogers.com> <20130813192353.GI7306@csclub.uwaterloo.ca> Message-ID: <20130814043729.GA3238@waltdnes.org> On Tue, Aug 13, 2013 at 03:23:53PM -0400, Lennart Sorensen wrote > On Tue, Aug 13, 2013 at 02:14:07PM -0400, James Knott wrote: > > Those that can, do. Those that can't, teach. ;-) > > > > Actually, he was OK as a math teacher. > > Very likely. We seem to have had more time to develop teachers for math > than computers. :) The other problem is that computing is a rapidly-changing field. You can take a 20-year-old math textbook, and it would still be almost totally valid today. There have been a few esoteric advanced conjectures/theorems rigorously proven since then, but that's about it. Do you really want to use 20-year-old tech and 20-year-old texts to teach computer programming today? Showing my age here.. as a kid growing up in the 1960's, I remember the days of keypunch operators taking a few night courses in FORTRAN, and getting good-paying jobs as programmers. Those days are long past. -- Walter Dnes I don't run "desktop environments"; I run useful applications -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From sciguy-Ja3L+HSX0kI at public.gmane.org Wed Aug 14 05:01:08 2013 From: sciguy-Ja3L+HSX0kI at public.gmane.org (Paul King) Date: Wed, 14 Aug 2013 01:01:08 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <20130813175348.GG7306-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> Message-ID: <000001ce98ab$4aae75a0$e00b60e0$@net> I can't speak for "bad teachers", since I have really been teaching senior math and qualified to teach both subject areas. Our school has never offered comp sci, being too small. In my experience there is a lot of student romanticism that precedes entry to computer science for the first time. There are people who want to write a killer Flash app first time out, and become dismayed when they find to their horror that it means learning ActionScript and going through a lot of OOP concepts, and that we should probably start with something easier to think about while covering some basic stuff like "if" statements and looping. And maybe even a function or two. Choices for a first teaching language vary wildly among teachers and institutions. I still recommend something procedural like Turing or Lazarus, but most teachers these days, afraid of losing students will surrender to Visual Basic, even though the latter is costly, but can arguably be massaged into a grade 10 teaching language (.NET is a little more iffy in Grade 10, IMO). I dislike their choice, but I understand that this is the common wisdom, due to pressure from administrators to keep the numbers of interested students up in their classrooms. Just the simple fact that VB has more cachet with students than Turing or Lazarus, even with its VB-like RAD GUI, is enough reason to reject such teaching languages. Python has been suggested (and is the first language taught in many universities to those who are raw beginners), but IMO it plays too fast and loose with data types. Since knowing data types is taught in grade 10 for the first time, it wouldn't be a good idea to expect students to understand, let alone trace errors, in such code. The only way to go here and stick honestly to the Ministry objectives is to select a language that uses strict typing. Hence, my choices from the Pascal family. Languages like C, C++, and Python can be taught in Grade 11 or 12 once the basics are out of the way. I guess that the real problem here is that, while there are good and bad teachers in all subjects, computer science teaching is influenced by admin expectations that numbers of students have to be up to a certain level each September, student expectations that don't match the realities of the course, and the teacher's choice of teaching language (admin pressure to "keep numbers up" for class funding goes back to Mike Harris and the funding formula, which still prevails). Paul King > -----Original Message----- > From: owner-tlug-lxSQFCZeNF4 at public.gmane.org [mailto:owner-tlug-lxSQFCZeNF4 at public.gmane.org] On Behalf Of Lennart > Sorensen > Sent: Tuesday, August 13, 2013 1:54 PM > To: tlug-lxSQFCZeNF4 at public.gmane.org > Subject: Re: [TLUG]: Semi-OT: Why Kids Can't use Computers > > On Mon, Aug 12, 2013 at 10:00:04PM -0400, James Knott wrote: > > Way back when I was in grade 12, I took a Fortran class that was > > taught by a math teacher. It soon became apparent he didn't know > much > > more about it than we did. > > Well some people are bad teachers. > > It does seem that highschools don't generally have much luck attracting > teachers that actually know how to teach programming. At least I > haven't encountered any yet. I suspect most of those that could teach > programming are either teaching at college or university, or actually > programming for a living instead. > > -- > Len Sorensen > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to > UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From marc-bbkyySd1vPWsTnJN9+BGXg at public.gmane.org Wed Aug 14 05:27:45 2013 From: marc-bbkyySd1vPWsTnJN9+BGXg at public.gmane.org (Marc Lijour) Date: Wed, 14 Aug 2013 01:27:45 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <000001ce98ab$4aae75a0$e00b60e0$@net> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> Message-ID: <520B1551.6030101@lijour.net> Don't get bogged down with specific expectations. The spirit of the curriculum is to get something done (action) in a fun way that allows students to learn something about programming (theory and practice). There is no silver bullet. Some faculty dislike programming classes in high school so they do their best to teach CS from scratch. The idea in high school is not to get students to become experts, but to focus on something they can truly learn and to allow them to develop a love and an objective appreciation of computer science. Computer science is also is terrific tool to teach other disciplines. Check this Google Engineer experience of Computer Science in Vietnam: https://neil.fraser.name/news/2013/03/16/ On Wed 14 Aug 2013 01:01:08 AM EDT, Paul King wrote: > I can't speak for "bad teachers", since I have really been teaching senior > math and qualified to teach both subject areas. Our school has never offered > comp sci, being too small. In my experience there is a lot of student > romanticism that precedes entry to computer science for the first time. > There are people who want to write a killer Flash app first time out, and > become dismayed when they find to their horror that it means learning > ActionScript and going through a lot of OOP concepts, and that we should > probably start with something easier to think about while covering some > basic stuff like "if" statements and looping. And maybe even a function or > two. > > Choices for a first teaching language vary wildly among teachers and > institutions. I still recommend something procedural like Turing or Lazarus, > but most teachers these days, afraid of losing students will surrender to > Visual Basic, even though the latter is costly, but can arguably be massaged > into a grade 10 teaching language (.NET is a little more iffy in Grade 10, > IMO). I dislike their choice, but I understand that this is the common > wisdom, due to pressure from administrators to keep the numbers of > interested students up in their classrooms. Just the simple fact that VB has > more cachet with students than Turing or Lazarus, even with its VB-like RAD > GUI, is enough reason to reject such teaching languages. > > Python has been suggested (and is the first language taught in many > universities to those who are raw beginners), but IMO it plays too fast and > loose with data types. Since knowing data types is taught in grade 10 for > the first time, it wouldn't be a good idea to expect students to understand, > let alone trace errors, in such code. The only way to go here and stick > honestly to the Ministry objectives is to select a language that uses strict > typing. Hence, my choices from the Pascal family. Languages like C, C++, and > Python can be taught in Grade 11 or 12 once the basics are out of the way. > > I guess that the real problem here is that, while there are good and bad > teachers in all subjects, computer science teaching is influenced by admin > expectations that numbers of students have to be up to a certain level each > September, student expectations that don't match the realities of the > course, and the teacher's choice of teaching language (admin pressure to > "keep numbers up" for class funding goes back to Mike Harris and the funding > formula, which still prevails). > > Paul King > >> -----Original Message----- >> From: owner-tlug-lxSQFCZeNF4 at public.gmane.org [mailto:owner-tlug-lxSQFCZeNF4 at public.gmane.org] On Behalf Of Lennart >> Sorensen >> Sent: Tuesday, August 13, 2013 1:54 PM >> To: tlug-lxSQFCZeNF4 at public.gmane.org >> Subject: Re: [TLUG]: Semi-OT: Why Kids Can't use Computers >> >> On Mon, Aug 12, 2013 at 10:00:04PM -0400, James Knott wrote: >>> Way back when I was in grade 12, I took a Fortran class that was >>> taught by a math teacher. It soon became apparent he didn't know >> much >>> more about it than we did. >> >> Well some people are bad teachers. >> >> It does seem that highschools don't generally have much luck attracting >> teachers that actually know how to teach programming. At least I >> haven't encountered any yet. I suspect most of those that could teach >> programming are either teaching at college or university, or actually >> programming for a living instead. >> >> -- >> Len Sorensen >> -- >> The Toronto Linux Users Group. Meetings: http://gtalug.org/ >> TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to >> UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Wed Aug 14 14:25:26 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Wed, 14 Aug 2013 10:25:26 -0400 (EDT) Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <520B1551.6030101-bbkyySd1vPWsTnJN9+BGXg@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <520B1551.6030101@lijour.net> Message-ID: | From: Marc Lijour | Computer science is also is terrific tool to teach other disciplines. | Check this Google Engineer experience of Computer Science in Vietnam: | https://neil.fraser.name/news/2013/03/16/ Nice. Thanks. Confirms and amplifies too many of my stereotypes -- I must beware. "Vietnam is a 100% Windows XP monoculture. Probably all with the same serial number. However, given that a copy of Windows costs one month's salary, it's easy to understand." Linux needs to get Microsoft to enforce its copyright. This too is old news. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Wed Aug 14 14:29:00 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Wed, 14 Aug 2013 10:29:00 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <520B1551.6030101-bbkyySd1vPWsTnJN9+BGXg@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <520B1551.6030101@lijour.net> Message-ID: <20130814142900.GJ7306@csclub.uwaterloo.ca> On Wed, Aug 14, 2013 at 01:27:45AM -0400, Marc Lijour wrote: > Don't get bogged down with specific expectations. The spirit of the > curriculum is to get something done (action) in a fun way that allows > students to learn something about programming (theory and practice). > > There is no silver bullet. Some faculty dislike programming classes in > high school so they do their best to teach CS from scratch. The idea in > high school is not to get students to become experts, but to focus on > something they can truly learn and to allow them to develop a love and > an objective appreciation of computer science. > > Computer science is also is terrific tool to teach other disciplines. > Check this Google Engineer experience of Computer Science in Vietnam: > https://neil.fraser.name/news/2013/03/16/ I know at least one person that did take CS courses in high school and decided computer science wasn't interesting as a result. That's how bad high schools often are at teaching programming. It's boring, trivial, and pointless. I suspect many colleges and universities would rather deal with students that haven't already ben damaged by high school programming courses. A lot less bad habits and misunderstandings to get rid of that way. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Wed Aug 14 14:36:08 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Wed, 14 Aug 2013 10:36:08 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <000001ce98ab$4aae75a0$e00b60e0$@net> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> Message-ID: <20130814143608.GK7306@csclub.uwaterloo.ca> On Wed, Aug 14, 2013 at 01:01:08AM -0400, Paul King wrote: > I can't speak for "bad teachers", since I have really been teaching senior > math and qualified to teach both subject areas. Our school has never offered > comp sci, being too small. In my experience there is a lot of student > romanticism that precedes entry to computer science for the first time. > There are people who want to write a killer Flash app first time out, and > become dismayed when they find to their horror that it means learning > ActionScript and going through a lot of OOP concepts, and that we should > probably start with something easier to think about while covering some > basic stuff like "if" statements and looping. And maybe even a function or > two. > > Choices for a first teaching language vary wildly among teachers and > institutions. I still recommend something procedural like Turing or Lazarus, > but most teachers these days, afraid of losing students will surrender to > Visual Basic, even though the latter is costly, but can arguably be massaged > into a grade 10 teaching language (.NET is a little more iffy in Grade 10, > IMO). I dislike their choice, but I understand that this is the common > wisdom, due to pressure from administrators to keep the numbers of > interested students up in their classrooms. Just the simple fact that VB has > more cachet with students than Turing or Lazarus, even with its VB-like RAD > GUI, is enough reason to reject such teaching languages. > > Python has been suggested (and is the first language taught in many > universities to those who are raw beginners), but IMO it plays too fast and > loose with data types. Since knowing data types is taught in grade 10 for > the first time, it wouldn't be a good idea to expect students to understand, > let alone trace errors, in such code. The only way to go here and stick > honestly to the Ministry objectives is to select a language that uses strict > typing. Hence, my choices from the Pascal family. Languages like C, C++, and > Python can be taught in Grade 11 or 12 once the basics are out of the way. Waterloo starts with scheme, then moves to scheme and C for the next course before getting into more complex things in the second year. Even non CS majors still start with scheme before moving to python. https://www.student.cs.uwaterloo.ca/~cs135/prospective Before that it used to be first year was java (for the first decade of this century), and in the nineties they used pascal for the first year courses (and modula 3 for the second year courses along with some scheme and DLX assembly). > I guess that the real problem here is that, while there are good and bad > teachers in all subjects, computer science teaching is influenced by admin > expectations that numbers of students have to be up to a certain level each > September, student expectations that don't match the realities of the > course, and the teacher's choice of teaching language (admin pressure to > "keep numbers up" for class funding goes back to Mike Harris and the funding > formula, which still prevails). Perhaps they should be looking at some of the more modern designs for teaching programming concepts, like scratch. (http://scratch.mit.edu/) It is certainly aimed at kids, although perhaps not highschool level, although if they really just want to make something cool quickly to start, maybe it actually is the right kind of thing. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Wed Aug 14 18:42:17 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Wed, 14 Aug 2013 14:42:17 -0400 (EDT) Subject: decent mega-monitor? In-Reply-To: References: Message-ID: I just got a notice from Amazon.com (not .ca, sadly) that the 39" one is $699 and the $50" one is $1,135.48. The 39" ought to be great as a monitor. Too bad about the 30 Hz refresh limit (due to HDMI bandwidth limitations). This reviewer even tells how he got an X modeline for it (he loves it): amazon.ca doesn't sell these. tigerdirect.ca only sells the 50" model (at $1299.97). | From: D. Hugh Redelmeier | Date: Tue, 30 Apr 2013 13:36:11 -0400 (EDT) | | There is a slow move towards talking about supporting "4k" HD TV. This | seems to mean 3840 x 2160 pixels (up from 1920 x 1080). You hear of | prices like $20k for TV sets. Here's a startlingly low price: | | Only $1,499.97 for 50" 3840 x 2160 display. | | Specs: | | | That sounds like a lot of money for a monitor but it isn't much more | than a 30" 2560 x 1600. | | Does anybody know if this actually makes a good computer monitor for a | conventional desktop? I've noticed that some TVs look inferior as | computer desktop monitors, even though their specs look appropriate. | | The refresh rate is probably not good enough. The monitor is fed by | an HDMI 1.4 monitor and I understand that the HDMI standard doesn't | have enough bandwidth to drive this resolution at more than 30Hz. | Apparently the next HDMI standard will improve this. The display can | refresh at 120Hz at lower resolution. This limitation seems to be | reported in the specs: the top resolution for component and HDMI is | listed as "4k2k 30Hz". Note: one of the user comments says that it | does work at 120Hz at full resolution. So I'm confused. | | The top VGA resolution listed is 3840 x 2160 (with no mention of | refresh rate). What VGA interface would drive that? In my | experience, VGA isn't great for LCDs because the two sides don't share | a clock and this leads to unpleasant artifacts. | | This probably uses TN technology since that isn't specified (if it | were IPS, that would be mentioned). TN makes viewing angle critical | and with a desktop monitor that big, only a portion of the screen | would be in the sweet spot. Mind you, the specs say 176 degree | viewing angles, horizontally and virtically. | | This review damns it with faint praise as a TV. | -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From ted.leslie-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Wed Aug 14 19:02:48 2013 From: ted.leslie-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (ted leslie) Date: Wed, 14 Aug 2013 15:02:48 -0400 Subject: decent mega-monitor? In-Reply-To: References: Message-ID: SWEET! but at that price, say compared to the HP 30" at double+$ the 39" Seiki, you have to wonder if it is not going to compare? Also, i have a 800$ quad dual-dual-link dvi kvm, and I am guessing it isn't going to support this quadHD res. :( and would there even be a dual monitor pairing kvm for this yet. I guess I can get a separate KVM just for one of them at first, and add it to my current dual 30" setup, just have to reinforce my desk, assuming they even make a KVM for a single even. Another thing is, with all that brightness staring so close, I turn my vid. brightness down and then have a script on linux (just button and hotkey) to toggle it and push new settings to nvideo config file then refresh it. With these beasts, especially if you dual or triple head them you would have to run them pretty dim else risk burning your eyes out. So then these beasts would have to have really good low brightness contract/quality. If I could see one in action, and it was half decent, I would grab one now ..... but if it were on 16 hours a day 300 days a year, wonder how it would hold up, and if any issues...... Maybe just get one as a third monitor and know if its a dud as a monitor, it could be relegated to a tv. Have to see what nvidia has to even run these beast, and what Xorg will think of a desktop of (twin portrait) of 4320 x 3840, and do they have brackets to allow portrait. Keep us (well free to email direct to me) updated if you get anymore info, or get to see one. -tl On Wed, Aug 14, 2013 at 2:42 PM, D. Hugh Redelmeier wrote: > I just got a notice from Amazon.com (not .ca, sadly) that the 39" one is > $699 and the $50" one is $1,135.48. > > > The 39" ought to be great as a monitor. Too bad about the 30 Hz refresh > limit (due to HDMI bandwidth limitations). > > This reviewer even tells how he got an X modeline for it (he loves it): > < > http://www.amazon.com/Seiki-Digital-SE39UY04-39-Inch-Ultra/product-reviews/B00DOPGO2G/ref=cm_cr_dp_text?ie=UTF8&showViewpoints=0&sortBy=byRankDescending#R3R4Y6PPZ1QN29 > > > > amazon.ca doesn't sell these. tigerdirect.ca only sells the 50" model (at > $1299.97). > > | From: D. Hugh Redelmeier > | Date: Tue, 30 Apr 2013 13:36:11 -0400 (EDT) > | > | There is a slow move towards talking about supporting "4k" HD TV. This > | seems to mean 3840 x 2160 pixels (up from 1920 x 1080). You hear of > | prices like $20k for TV sets. Here's a startlingly low price: > | < > http://www.tigerdirect.ca/applications/SearchTools/item-details.asp?EdpNo=7674736&CatId=4717 > > > | Only $1,499.97 for 50" 3840 x 2160 display. > | > | Specs: > | < > http://static.highspeedbackbone.net/pdf/Seiki%20SE50UY04%204K2K%20LED%20HDTV%20Data%20Sheet.pdf > > > | > | That sounds like a lot of money for a monitor but it isn't much more > | than a 30" 2560 x 1600. > | > | Does anybody know if this actually makes a good computer monitor for a > | conventional desktop? I've noticed that some TVs look inferior as > | computer desktop monitors, even though their specs look appropriate. > | > | The refresh rate is probably not good enough. The monitor is fed by > | an HDMI 1.4 monitor and I understand that the HDMI standard doesn't > | have enough bandwidth to drive this resolution at more than 30Hz. > | Apparently the next HDMI standard will improve this. The display can > | refresh at 120Hz at lower resolution. This limitation seems to be > | reported in the specs: the top resolution for component and HDMI is > | listed as "4k2k 30Hz". Note: one of the user comments says that it > | does work at 120Hz at full resolution. So I'm confused. > | > | The top VGA resolution listed is 3840 x 2160 (with no mention of > | refresh rate). What VGA interface would drive that? In my > | experience, VGA isn't great for LCDs because the two sides don't share > | a clock and this leads to unpleasant artifacts. > | > | This probably uses TN technology since that isn't specified (if it > | were IPS, that would be mentioned). TN makes viewing angle critical > | and with a desktop monitor that big, only a portion of the screen > | would be in the sweet spot. Mind you, the specs say 176 degree > | viewing angles, horizontally and virtically. > | > | This review damns it with faint praise as a TV. > | > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -------------- next part -------------- An HTML attachment was scrubbed... URL: From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Wed Aug 14 20:47:07 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Wed, 14 Aug 2013 16:47:07 -0400 (EDT) Subject: decent mega-monitor? In-Reply-To: References: Message-ID: | From: ted leslie | SWEET! but at that price, say compared to the HP 30" at double+$ the 39" | Seiki, you have to wonder | if it is not going to compare? What I want is the mass market to supply the things I want. I've been really disappointed in the lack of price movement, takeup and improvement of 30" 2560x1600 monitors. I've had mine for 7.5 years (almost 4 cycles of Moore's law). Analogy: I bought a couple of Sun workstations (sequentially) but eventually the PC got good enough and I saved a bundle and had a lot of choices. Of course the PCs were not made to the mechanical standards or sanity of Suns, but they sure were good enough. I keep expecting higher resolution to become mas market. The glimmers of hope are: - Apple "retina" displays - tablets and cell phones in resolution wars - "4k" TV around the corner. This 39" Seiki is almost good enough (on paper). And a very nice price considering that there is no competition to speak of. | Also, i have a 800$ quad dual-dual-link dvi kvm, and I am guessing it isn't | going to support this | quadHD res. :( I don't know what a dual-dual-link DVI KVM is. Does it switch pairs of DVI connections, each of which is dual-link? I assume "quad" means that four different computer systems are connected to the switch, exactly one of which is actually connected to the keyboard, video, and mouse (+USB probably). I think that it would work, but I don't know. DVI and single-link HDMI are or were essentially the same: a cable with two appropriate connectors are all you need for conversion, I think. At 30 Hz, HDMI *can* drive this monitor, but I'm not sure that that's within specs for single-link DVI. | and would there even be a dual monitor pairing kvm for | this yet. I guess I can | get a separate KVM just for one of them at first, and add it to my current | dual 30" setup, HDMI switches can be quite inexpensive ($20?) but they are made for video and don't have any keyboard capability. | Keep us (well free to email direct to me) updated if you get anymore info, | or get to see one. Are you visiting the US soon? With a car? :-) I hope that 6 months or a year of patience might be rewarded with something like this with a higher-bandwidth input. $700 is hard to resist. The price seems to have crept down: maybe that means that something new is about to replace it. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Wed Aug 14 21:19:17 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Wed, 14 Aug 2013 17:19:17 -0400 Subject: decent mega-monitor? In-Reply-To: References: Message-ID: <20130814211917.GL7306@csclub.uwaterloo.ca> On Wed, Aug 14, 2013 at 04:47:07PM -0400, D. Hugh Redelmeier wrote: > What I want is the mass market to supply the things I want. I've been > really disappointed in the lack of price movement, takeup and > improvement of 30" 2560x1600 monitors. I've had mine for 7.5 years > (almost 4 cycles of Moore's law). > > Analogy: I bought a couple of Sun workstations (sequentially) but > eventually the PC got good enough and I saved a bundle and had a lot > of choices. Of course the PCs were not made to the mechanical > standards or sanity of Suns, but they sure were good enough. > > I keep expecting higher resolution to become mas market. The glimmers > of hope are: > > - Apple "retina" displays > > - tablets and cell phones in resolution wars > > - "4k" TV around the corner. > > This 39" Seiki is almost good enough (on paper). And a very nice > price considering that there is no competition to speak of. > > I don't know what a dual-dual-link DVI KVM is. Does it switch pairs > of DVI connections, each of which is dual-link? I assume "quad" > means that four different computer systems are connected to the > switch, exactly one of which is actually connected to the keyboard, > video, and mouse (+USB probably). Sounds like a two monitor dual link KVM switch, which would allow driving two 30" monster screens at 2560x1600 resolution and switch them between four machines. Dual link DVI should be able to drive a 4k display at 30Hz, but of course no TV comes with dual link DVI ports, and none have dual link HDMI-B either (it seems nothing has HDMI-B dual link ports). Too bad TVs don't seem to have displayport on them to allow good use with computers. HDMI 2.0 will solve the problem of course by doubling the bandwidth of HDMI 1.4 and hence allowing 60 Hz 4k displays (3D will have to do 30Hz or half resolution of course, but that seems to be what they have often been doing anyhow so far). > I think that it would work, but I don't know. DVI and single-link > HDMI are or were essentially the same: a cable with two appropriate > connectors are all you need for conversion, I think. At 30 Hz, HDMI > *can* drive this monitor, but I'm not sure that that's within specs > for single-link DVI. It isn't. Single Link (which HDMI is) DVI only supports the original HDMI signal speed, not the new high speed modes that were added in later versions of the HDMI standard (which the 4k uses to even get 30Hz refresh). > HDMI switches can be quite inexpensive ($20?) but they are made for > video and don't have any keyboard capability. > > Are you visiting the US soon? With a car? :-) > > I hope that 6 months or a year of patience might be rewarded with > something like this with a higher-bandwidth input. $700 is hard to > resist. The price seems to have crept down: maybe that means that > something new is about to replace it. Well things seem to get cheaper. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From ted.leslie-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Wed Aug 14 21:38:54 2013 From: ted.leslie-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (ted leslie) Date: Wed, 14 Aug 2013 17:38:54 -0400 Subject: decent mega-monitor? In-Reply-To: <20130814211917.GL7306-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130814211917.GL7306@csclub.uwaterloo.ca> Message-ID: Yes its a http://www.iogear.com/product/GCS1644/ quad dual view dual link dvi. So 10 video cables go into it, 4 computers with two sets of dvi each, and one set to actual monitors. On keyboard ctrl sequence, it switch both monitors across to selected computer, and it multiplex the keyboard, mouse, usb, and audio. So I don't understand, you say dual link dvi should be able to drive a 4k ..... but no tv has that dual link port, so what does a 4k tv have? and can i convert with a simple adapter plug of some kind? Also, I am wondering, wouldn't the kvm have to support the resolution specifically? I do have a cable that plugs in the nvidia dvi and goes to hdmi on a 50" plasma, so it would be something like that? -tl On Wed, Aug 14, 2013 at 5:19 PM, Lennart Sorensen < lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org> wrote: > On Wed, Aug 14, 2013 at 04:47:07PM -0400, D. Hugh Redelmeier wrote: > > What I want is the mass market to supply the things I want. I've been > > really disappointed in the lack of price movement, takeup and > > improvement of 30" 2560x1600 monitors. I've had mine for 7.5 years > > (almost 4 cycles of Moore's law). > > > > Analogy: I bought a couple of Sun workstations (sequentially) but > > eventually the PC got good enough and I saved a bundle and had a lot > > of choices. Of course the PCs were not made to the mechanical > > standards or sanity of Suns, but they sure were good enough. > > > > I keep expecting higher resolution to become mas market. The glimmers > > of hope are: > > > > - Apple "retina" displays > > > > - tablets and cell phones in resolution wars > > > > - "4k" TV around the corner. > > > > This 39" Seiki is almost good enough (on paper). And a very nice > > price considering that there is no competition to speak of. > > > > I don't know what a dual-dual-link DVI KVM is. Does it switch pairs > > of DVI connections, each of which is dual-link? I assume "quad" > > means that four different computer systems are connected to the > > switch, exactly one of which is actually connected to the keyboard, > > video, and mouse (+USB probably). > > Sounds like a two monitor dual link KVM switch, which would allow driving > two 30" monster screens at 2560x1600 resolution and switch them between > four machines. Dual link DVI should be able to drive a 4k display at > 30Hz, but of course no TV comes with dual link DVI ports, and none have > dual link HDMI-B either (it seems nothing has HDMI-B dual link ports). > Too bad TVs don't seem to have displayport on them to allow good use > with computers. HDMI 2.0 will solve the problem of course by doubling > the bandwidth of HDMI 1.4 and hence allowing 60 Hz 4k displays (3D will > have to do 30Hz or half resolution of course, but that seems to be what > they have often been doing anyhow so far). > > > I think that it would work, but I don't know. DVI and single-link > > HDMI are or were essentially the same: a cable with two appropriate > > connectors are all you need for conversion, I think. At 30 Hz, HDMI > > *can* drive this monitor, but I'm not sure that that's within specs > > for single-link DVI. > > It isn't. Single Link (which HDMI is) DVI only supports the original > HDMI signal speed, not the new high speed modes that were added in > later versions of the HDMI standard (which the 4k uses to even get > 30Hz refresh). > > > HDMI switches can be quite inexpensive ($20?) but they are made for > > video and don't have any keyboard capability. > > > > Are you visiting the US soon? With a car? :-) > > > > I hope that 6 months or a year of patience might be rewarded with > > something like this with a higher-bandwidth input. $700 is hard to > > resist. The price seems to have crept down: maybe that means that > > something new is about to replace it. > > Well things seem to get cheaper. > > -- > Len Sorensen > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -------------- next part -------------- An HTML attachment was scrubbed... URL: From opengeometry-FFYn/CNdgSA at public.gmane.org Wed Aug 14 22:26:59 2013 From: opengeometry-FFYn/CNdgSA at public.gmane.org (William Park) Date: Wed, 14 Aug 2013 18:26:59 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <20130813175348.GG7306-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> Message-ID: <20130814222659.GA16241@node1.localdomain> On Tue, Aug 13, 2013 at 01:53:48PM -0400, Lennart Sorensen wrote: > On Mon, Aug 12, 2013 at 10:00:04PM -0400, James Knott wrote: > > Way back when I was in grade 12, I took a Fortran class that was taught > > by a math teacher. It soon became apparent he didn't know much more > > about it than we did. > > Well some people are bad teachers. Teachers are just those who went to Teacher's College. The subjects they are teaching are irrelevant to the teaching license. -- William -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From opengeometry-FFYn/CNdgSA at public.gmane.org Wed Aug 14 22:32:53 2013 From: opengeometry-FFYn/CNdgSA at public.gmane.org (William Park) Date: Wed, 14 Aug 2013 18:32:53 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <000001ce98ab$4aae75a0$e00b60e0$@net> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> Message-ID: <20130814223253.GB16241@node1.localdomain> On Wed, Aug 14, 2013 at 01:01:08AM -0400, Paul King wrote: > ... Hence, my choices from the Pascal family. Languages like C, C++, and > Python can be taught in Grade 11 or 12 once the basics are out of the way. Off topic... what really happened to Pascal/Modula-X ? >From my memory, it had pretty fast compile time, and they could've added more data structures into the language if needed. -- William -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From thoriumbr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 15 01:35:04 2013 From: thoriumbr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Mauro Souza) Date: Wed, 14 Aug 2013 22:35:04 -0300 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <20130814223253.GB16241-+21/tKCbORjP0Z7Jsv878P8+0UxHXcjY@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <20130814223253.GB16241@node1.localdomain> Message-ID: Pascal died when Delphi died with Borland, crushed by Java and .NET. I had Pascal on my first semester on college, and never ever touched Pascal again. I had a lot of colleages on college that programmed Pascal/Delphi for living, but their numbers got thinner every year. almost everybody migrated their skills to Java/.Net or became DBAs or sysadmins. I worked with VB (and made fun of my Delphy colleages when Borland died), and migrated to system administration. Is more fun, pays more, and have more "job security" than programming... Today C/Java/.NET dominates the desktop and enterprise market, with PHP/Python/Ruby/Javascript on the webservers, and Pascal is not much relevant anymore. Mauro http://mauro.limeiratem.com - registered Linux User: 294521 Scripture is both history, and a love letter from God. 2013/8/14 William Park > On Wed, Aug 14, 2013 at 01:01:08AM -0400, Paul King wrote: > > ... Hence, my choices from the Pascal family. Languages like C, C++, and > > Python can be taught in Grade 11 or 12 once the basics are out of the > way. > > Off topic... what really happened to Pascal/Modula-X ? > From my memory, it had pretty fast compile time, and they could've added > more data structures into the language if needed. > -- > William > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -------------- next part -------------- An HTML attachment was scrubbed... URL: From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Thu Aug 15 02:09:00 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Wed, 14 Aug 2013 22:09:00 -0400 (EDT) Subject: decent mega-monitor? In-Reply-To: References: <20130814211917.GL7306@csclub.uwaterloo.ca> Message-ID: | From: ted leslie | Yes its a http://www.iogear.com/product/GCS1644/ quad dual view dual link | dvi. So 10 video cables go into it, | 4 computers with two sets of dvi each, and one set to actual monitors. On | keyboard ctrl sequence, it switch both monitors | across to selected computer, and it multiplex the keyboard, mouse, usb, and | audio. Right. I have a GCS1784 but haven't yet installed it (4 computers, one dual-link DVI monitor). | So I don't understand, you say dual link dvi should be able to drive a 4k | ..... | but no tv has that dual link port, so what does a 4k tv have? The one I pointed to ONLY has HDMI. Lennart points out that DVI-to-HDMI cannot drive this monitor in 4K mode (HDMI's spec has moved beyond single-link DVI and there is no sensible conversion from dual-link DVI to high-bandwidth HDMI (i.e. nothing beyond what single-link can do). Other (way more expensive) 4K TV monitors have other provisions. You can infer something about them from the (unclear) tables in | and can i | convert with a simple adapter plug of some kind? For some, 2xDLDVI provides the input. Of course that means the video card driver has to know how to split the frame over two video outputs. | Also, I am wondering, wouldn't the kvm have to support the resolution | specifically? For some (expensive) monitors, I think your KVM could support one monitor (not two). | I do have a cable that plugs in the nvidia dvi and goes to hdmi on a 50" | plasma, so it would be something like that? No. That is limited to 1920x1200 @ 60. HDMI itself (if your card has the current standard) can do more. That's what Lennart clarified. What a mess. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From sciguy-Ja3L+HSX0kI at public.gmane.org Thu Aug 15 02:17:15 2013 From: sciguy-Ja3L+HSX0kI at public.gmane.org (Paul King) Date: Wed, 14 Aug 2013 22:17:15 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <20130814223253.GB16241-+21/tKCbORjP0Z7Jsv878P8+0UxHXcjY@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <20130814223253.GB16241@node1.localdomain> Message-ID: <002201ce995d$8fef3570$afcda050$@net> Well, lessee... Pascal was bested by Turbo Pascal, which in turn was bested by Delphi (both Borland products), which is an expensive competitor against VB.NET. Delphi has changed hands many times and is currently produced by Embracadero. Embracadero is promising to release a linux version, rumor has it. Hope they don't cheap out and use WINE as Borland tried to do with Kylix. If no one on this list but me has heard of Kylix, I rest my case :-) Delphi now has increased competition from MS, in that MS has released free licenses of Visual Studio under the banner of "Visual Studio 2012 .NET Express". So, anyone with a pirated copy of VB can uninstall it now :-) I don't think a school license of VB.NET express is possible. To those of us who want a compile-able Pascal with a GUI and can't afford Embracadero's price tag, the rest of us have the open-source Lazarus to program in. My impression is that the exe's are not as efficient (too big) as one would like. But you had a basic GUI with some internet socketing, OOP, and actual GNU-Pascal if you still want the command line. Lazarus is write once, compile anywhere, and has Windows and Linux versions. It is GPL, afaik, or at the very least open-source. Paul King > -----Original Message----- > From: owner-tlug-lxSQFCZeNF4 at public.gmane.org [mailto:owner-tlug-lxSQFCZeNF4 at public.gmane.org] On Behalf Of William > Park > Sent: Wednesday, August 14, 2013 6:33 PM > To: tlug-lxSQFCZeNF4 at public.gmane.org > Subject: Re: [TLUG]: Semi-OT: Why Kids Can't use Computers > > On Wed, Aug 14, 2013 at 01:01:08AM -0400, Paul King wrote: > > ... Hence, my choices from the Pascal family. Languages like C, C++, > > and Python can be taught in Grade 11 or 12 once the basics are out of > the way. > > Off topic... what really happened to Pascal/Modula-X ? > From my memory, it had pretty fast compile time, and they could've > added more data structures into the language if needed. > -- > William > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to > UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From sciguy-Ja3L+HSX0kI at public.gmane.org Thu Aug 15 02:27:11 2013 From: sciguy-Ja3L+HSX0kI at public.gmane.org (Paul King) Date: Wed, 14 Aug 2013 22:27:11 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <20130814223253.GB16241@node1.localdomain> Message-ID: <002301ce995e$f347d630$d9d78290$@net> Rumors of Borland "dying" are greatly exaggerated: http://borland.com/ From: owner-tlug-lxSQFCZeNF4 at public.gmane.org [mailto:owner-tlug-lxSQFCZeNF4 at public.gmane.org] On Behalf Of Mauro Souza Sent: Wednesday, August 14, 2013 9:35 PM To: tlug-lxSQFCZeNF4 at public.gmane.org Subject: Re: [TLUG]: Semi-OT: Why Kids Can't use Computers Pascal died when Delphi died with Borland, crushed by Java and .NET. I had Pascal on my first semester on college, and never ever touched Pascal again. I had a lot of colleages on college that programmed Pascal/Delphi for living, but their numbers got thinner every year. almost everybody migrated their skills to Java/.Net or became DBAs or sysadmins. I worked with VB (and made fun of my Delphy colleages when Borland died), and migrated to system administration. Is more fun, pays more, and have more "job security" than programming... Today C/Java/.NET dominates the desktop and enterprise market, with PHP/Python/Ruby/Javascript on the webservers, and Pascal is not much relevant anymore. Mauro http://mauro.limeiratem.com - registered Linux User: 294521 Scripture is both history, and a love letter from God. 2013/8/14 William Park On Wed, Aug 14, 2013 at 01:01:08AM -0400, Paul King wrote: > ... Hence, my choices from the Pascal family. Languages like C, C++, and > Python can be taught in Grade 11 or 12 once the basics are out of the way. Off topic... what really happened to Pascal/Modula-X ? >From my memory, it had pretty fast compile time, and they could've added more data structures into the language if needed. -- William -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -------------- next part -------------- An HTML attachment was scrubbed... URL: From sciguy-Ja3L+HSX0kI at public.gmane.org Thu Aug 15 02:37:59 2013 From: sciguy-Ja3L+HSX0kI at public.gmane.org (Paul King) Date: Wed, 14 Aug 2013 22:37:59 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <002301ce995e$f347d630$d9d78290$@net> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <20130814223253.GB16241@node1.localdomain> <002301ce995e$f347d630$d9d78290$@net> Message-ID: <002b01ce9960$75541d40$5ffc57c0$@net> I replied too soon: I noticed they don't mention any actual languages in their offering of products. I guess they have died in a sense. C++ also seems to have been sold to Embracadero, along with other languages Borland once had. From: owner-tlug-lxSQFCZeNF4 at public.gmane.org [mailto:owner-tlug-lxSQFCZeNF4 at public.gmane.org] On Behalf Of Paul King Sent: Wednesday, August 14, 2013 10:27 PM To: tlug-lxSQFCZeNF4 at public.gmane.org Subject: RE: [TLUG]: Semi-OT: Why Kids Can't use Computers Rumors of Borland "dying" are greatly exaggerated: http://borland.com/ From: owner-tlug-lxSQFCZeNF4 at public.gmane.org [mailto:owner-tlug-lxSQFCZeNF4 at public.gmane.org] On Behalf Of Mauro Souza Sent: Wednesday, August 14, 2013 9:35 PM To: tlug-lxSQFCZeNF4 at public.gmane.org Subject: Re: [TLUG]: Semi-OT: Why Kids Can't use Computers Pascal died when Delphi died with Borland, crushed by Java and .NET. I had Pascal on my first semester on college, and never ever touched Pascal again. I had a lot of colleages on college that programmed Pascal/Delphi for living, but their numbers got thinner every year. almost everybody migrated their skills to Java/.Net or became DBAs or sysadmins. I worked with VB (and made fun of my Delphy colleages when Borland died), and migrated to system administration. Is more fun, pays more, and have more "job security" than programming... Today C/Java/.NET dominates the desktop and enterprise market, with PHP/Python/Ruby/Javascript on the webservers, and Pascal is not much relevant anymore. Mauro http://mauro.limeiratem.com - registered Linux User: 294521 Scripture is both history, and a love letter from God. 2013/8/14 William Park On Wed, Aug 14, 2013 at 01:01:08AM -0400, Paul King wrote: > ... Hence, my choices from the Pascal family. Languages like C, C++, and > Python can be taught in Grade 11 or 12 once the basics are out of the way. Off topic... what really happened to Pascal/Modula-X ? >From my memory, it had pretty fast compile time, and they could've added more data structures into the language if needed. -- William -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -------------- next part -------------- An HTML attachment was scrubbed... URL: From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Thu Aug 15 02:47:03 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Wed, 14 Aug 2013 22:47:03 -0400 (EDT) Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <520B1551.6030101-bbkyySd1vPWsTnJN9+BGXg@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <520B1551.6030101@lijour.net> Message-ID: | From: Marc Lijour | Check this Google Engineer experience of Computer Science in Vietnam: | https://neil.fraser.name/news/2013/03/16/ That got me reading I find it impossible to believe "that only 0.5% of people who submit their resumes for a programming job can pass FizzBuzz." -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From sciguy-Ja3L+HSX0kI at public.gmane.org Thu Aug 15 03:23:54 2013 From: sciguy-Ja3L+HSX0kI at public.gmane.org (Paul King) Date: Wed, 14 Aug 2013 23:23:54 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <520B1551.6030101@lijour.net> Message-ID: <003301ce9966$df9faa60$9edeff20$@net> in the same article: " ... [in the US] computer science homework is banned by the school board." Banned! Holy Toledo. I imagine a teacher facing having to be disciplined by the admin for the crime of assigning CS homework. In Peel [where I work] no one is banning CS homework, but it is discouraged in the profession for reasons of equity, since it is an equity issue to families who still don't have computers or Internet (and yes they really exist). Many schools in the GTA disregard this "ethic", I am hearing, including some schools in Peel. The schools in question may be in middle to upper class districts where it is not really an issue. Paul King > -----Original Message----- > From: owner-tlug-lxSQFCZeNF4 at public.gmane.org [mailto:owner-tlug-lxSQFCZeNF4 at public.gmane.org] On Behalf Of D. Hugh > Redelmeier > Sent: Wednesday, August 14, 2013 10:47 PM > To: tlug-lxSQFCZeNF4 at public.gmane.org > Subject: Re: [TLUG]: Semi-OT: Why Kids Can't use Computers > > | From: Marc Lijour > > | Check this Google Engineer experience of Computer Science in Vietnam: > | https://neil.fraser.name/news/2013/03/16/ > > That got me reading > > I find it impossible to believe "that only 0.5% of people who submit > their resumes for a programming job can pass FizzBuzz." > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to > UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Thu Aug 15 12:18:17 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Thu, 15 Aug 2013 08:18:17 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <002b01ce9960$75541d40$5ffc57c0$@net> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <20130814223253.GB16241@node1.localdomain> <002301ce995e$f347d630$d9d78290$@net> <002b01ce9960$75541d40$5ffc57c0$@net> Message-ID: <520CC709.2050204@rogers.com> Paul King wrote: > C++ also seems to have been sold to Embracadero, along with other > languages Borland once had. Several years ago, I took a C programming class at George Brown College. We used Borland's Turbo C++ on Windows 3.1. At home, I had Borland C++ for OS/2 (it's still on my shelf). I had to be careful, due to differences in integer size. As I recall, Borland's "Sidekick" TSR was popular way back in the DOS days. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Thu Aug 15 13:40:10 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Thu, 15 Aug 2013 09:40:10 -0400 (EDT) Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] In-Reply-To: <520CC709.2050204-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <20130814223253.GB16241@node1.localdomain> <002301ce995e$f347d630$d9d78290$@net> <002b01ce9960$75541d40$5ffc57c0$@net> <520CC709.2050204@rogers.com> Message-ID: | From: James Knott | I had to be careful, due | to differences in integer size. That is the nature of C. If you want to write portable code, you have to be careful about the width of integral types. Sadly, the language gives you inhumane tools for this. Since your experience, the C Standards have provided headers that let you select an integral type with a desired number of bits. But how does anyone know, for most variables, how many bits they need? Ignoring that, you kind of know that the following is a monotonically non-decreasingly wide sequence of types: signed char short int long long long intmaxt_t /* defined in inttypes.h */ Then there are unsigned variants. And plain char might be signed or not. When I first used C, the only char and int existed. All these others were accreted over time. Pascal was much better. You can use subrange types which let you specifiy bounds for your integral variables (like array bounds, but for integers). Aside from the fact that the bounds had to be known at compile time, it was quite helpful. I wrote a lot of code in Sue, an extended subset of Pascal that didn't even let you declare an integer variable: you always had to use a subrange. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 15 15:09:10 2013 From: cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Christopher Browne) Date: Thu, 15 Aug 2013 11:09:10 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <20130814223253.GB16241-+21/tKCbORjP0Z7Jsv878P8+0UxHXcjY@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <20130814223253.GB16241@node1.localdomain> Message-ID: On Wed, Aug 14, 2013 at 6:32 PM, William Park wrote: > On Wed, Aug 14, 2013 at 01:01:08AM -0400, Paul King wrote: >> ... Hence, my choices from the Pascal family. Languages like C, C++, and >> Python can be taught in Grade 11 or 12 once the basics are out of the way. > > Off topic... what really happened to Pascal/Modula-X ? > From my memory, it had pretty fast compile time, and they could've added > more data structures into the language if needed. Modula (Wirth) was created as a successor to Pascal, in effect, in part, to address the sorts of things that Brian Kernighan criticized (http://www.lysator.liu.se/c/bwk-on-pascal.html). It quite soon begat Modula-2 (Wirth), which was viable enough to grow a pretty large set of compilers (see: http://freepages.modula2.org/compi.html), many still available. Wirth created Oberon, which also included an operating system environment, as his "successor". Modula-3 was created as a joint venture of DEC and Olivetti research groups, and was quite interesting. Unfortunately, it was never nearly so popular as M2. The one "free software"-relevant piece of software made in M3 was CVSup, which was a system for synchronizing CVS archives, used pretty heavily by the BSD folk. http://www.modula3.org/ Most universities headed down the "we want to be vocational colleges rather than universities" path, and adopted Java instead. -- When confronted by a difficult problem, solve it by reducing it to the question, "How would the Lone Ranger handle this?" -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Thu Aug 15 15:59:03 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Thu, 15 Aug 2013 11:59:03 -0400 Subject: decent mega-monitor? In-Reply-To: References: <20130814211917.GL7306@csclub.uwaterloo.ca> Message-ID: <20130815155903.GM7306@csclub.uwaterloo.ca> On Wed, Aug 14, 2013 at 05:38:54PM -0400, ted leslie wrote: > Yes its a http://www.iogear.com/product/GCS1644/ quad dual view dual link > dvi. So 10 video cables go into it, > 4 computers with two sets of dvi each, and one set to actual monitors. On > keyboard ctrl sequence, it switch both monitors > across to selected computer, and it multiplex the keyboard, mouse, usb, and > audio. > > So I don't understand, you say dual link dvi should be able to drive a 4k > ..... Dual link DVI can do 2560x1600 @ 60Hz, which means it could do 4k @ 30Hz. > but no tv has that dual link port, so what does a 4k tv have? and can i > convert with a simple adapter plug of some kind? It would have to be an active adapter. As far as I can tell, no such adapter exists (I think some used to, but no longer do). I can't even find a dual link dvi to display port adapter. If such a thing existed, you would be able to convert that to HDMI 1.4 afterwards (although you would be using two active adapters at once). But no such luck either it seems. > Also, I am wondering, wouldn't the kvm have to support the resolution > specifically? The KVM should just have to pass the monitor's EDID data through and the video signal the other way. > I do have a cable that plugs in the nvidia dvi and goes to hdmi on a 50" > plasma, so it would be something like that? That would be single link only, and depending on what the nvidia does, that may or may not include higher link speeds. If they recognize the HDMI adapter being plugged in then they might choose to support HDMI 1.3+ link speeds, in which case it could do 4k resolution. If they don't, then it will just support 1920x1200. I suspect most nvidia cards capable of HDMI 1.3+ would actually have an HDMI port already on the card. Which nvidia card do you have? -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Thu Aug 15 16:01:29 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Thu, 15 Aug 2013 12:01:29 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <520B1551.6030101@lijour.net> Message-ID: <20130815160129.GN7306@csclub.uwaterloo.ca> On Wed, Aug 14, 2013 at 10:47:03PM -0400, D. Hugh Redelmeier wrote: > That got me reading > > I find it impossible to believe "that only 0.5% of people who submit > their resumes for a programming job can pass FizzBuzz." After giving a simple C test to many people being interviewed, I am unfortunately starting to believe it. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Thu Aug 15 16:10:12 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Thu, 15 Aug 2013 12:10:12 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <20130814223253.GB16241-+21/tKCbORjP0Z7Jsv878P8+0UxHXcjY@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <20130814223253.GB16241@node1.localdomain> Message-ID: <20130815161012.GO7306@csclub.uwaterloo.ca> On Wed, Aug 14, 2013 at 06:32:53PM -0400, William Park wrote: > Off topic... what really happened to Pascal/Modula-X ? > From my memory, it had pretty fast compile time, and they could've added > more data structures into the language if needed. Visual Studio took over, and did not include pascal. VisualBasic and VisualC++ took over, where TurboC and TurboPascal used to rule. I believe Delphi is somewhat pascal related, but I am not sure (never looked at it). A quick check says Delphi is Object Pascal, so yes that is related and somewhat popular. Modula-3 was the last, and was as far as I recall mainly worked on by DEC, who of course went out of business, and Compaq seemed to have no interest in continuing the work. Checking wikipedia seems to agree with what I recalled. It never had commercial interest, unlike Pascal which had some for a while. It pretty much seems that if Microsoft doesn't supposed it in Visual Studio these days, then the language is mostly doomed. But at the same time that doesn't seem to stop Perl, Python, PHP, etc. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From psema4-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 15 16:34:43 2013 From: psema4-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Scott Elcomb) Date: Thu, 15 Aug 2013 12:34:43 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: References: Message-ID: On Sun, Aug 11, 2013 at 2:18 PM, Colin McGregor wrote: > Ran across this story about why kids can't use computers, and the > story has some suggestions as to how to fix that (part of the > suggestion being the use of Linux): > > http://www.coding2learn.org/blog/2013/07/29/kids-cant-use-computers/ Thanks for posting this Colin. It's been stuck in my head ever since. :) While reading through I found myself checking off item after item. Having done support (through 3 tiers) and being the family (and local) tech, I've run into many similar examples. I think what spoke to me the most though was the bit about policy makers... "I have one question for these policy makers: Without reference to Wikipedia, can you tell me what the difference is between The Internet, The World Wide Web, a web-browser and a search engine? If you can?t, then you have no right to be making decisions that affect my use of these technologies." I absolutely, 100% and without reservation agree with this. That policy makers are as technologically illiterate as the masses is not surprising... but it's still frightening. -- Scott Elcomb @psema4 on Twitter / Identi.ca / Github & more Atomic OS: Self Contained Microsystems http://code.google.com/p/atomos/ Member of the Pirate Party of Canada http://www.pirateparty.ca/ -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From teddymills-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 15 16:59:19 2013 From: teddymills-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (teddy-public) Date: Thu, 15 Aug 2013 12:59:19 -0400 Subject: Why Kids Can't use Computers Message-ID: <520D08E7.8020502@gmail.com> A lot of it has to do with that computer technology is so common today. When personal computers were new, it was exciting. I remember 2 events. (cue the 2001 Space Odyssey soundtrack, the first tool) Buying an IBM XT clone for $700 and using it later to write device drivers in MASM. Second was someone showing me a NCSA Web browser for the first time and I connected to a webserver in California. Now a days, it is boring. I can spin up any server I want on the cloud in 5 minutes. And because computers are boring, kids are not interested. I too find computers boring. But the ideas and things they can do will likely never be boring. If I can mine bitcoins at 100GH, that is exciting. Today I am trying to get MYSQL MASTER-MASTER Replication working. If I can get that working, that to me, is exciting. The server hardware in Virginia does not interest me at all. -------------- next part -------------- An HTML attachment was scrubbed... URL: From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Thu Aug 15 17:54:31 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Thu, 15 Aug 2013 13:54:31 -0400 (EDT) Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) Message-ID: [A DCB message to the TLUG list. I'm forwarding because the list discards his mail.] ---------- Forwarded message ---------- From: David Collier-Brown To: tlug-lxSQFCZeNF4 at public.gmane.org Cc: D. Hugh Redelmeier Date: Thu, 15 Aug 2013 13:25:03 -0400 Subject: Re: [TLUG]: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] Reply-To: davecb-0XdUWXLQalXR7s880joybQ at public.gmane.org On 08/15/2013 09:40 AM, D. Hugh Redelmeier wrote: > | From: James Knott > > | I had to be careful, due > | to differences in integer size. > > That is the nature of C. If you want to write portable code, you have > to be careful about the width of integral types. Sadly, the > language gives you inhumane tools for this. > > Since your experience, the C Standards have provided headers that let > you select an integral type with a desired number of bits. But how > does anyone know, for most variables, how many bits they need? > > Ignoring that, you kind of know that the following is a monotonically > non-decreasingly wide sequence of types: > > signed char > short > int > long > long long > intmaxt_t /* defined in inttypes.h */ > > Then there are unsigned variants. And plain char might be signed or > not. > > When I first used C, the only char and int existed. All these others > were accreted over time. > > Pascal was much better. You can use subrange types which let you > specifiy bounds for your integral variables (like array bounds, but > for integers). Aside from the fact that the bounds had to be known > at compile time, it was quite helpful. > > I wrote a lot of code in Sue, an extended subset of Pascal that didn't > even let you declare an integer variable: you always had to use a > subrange. > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > Previous to C, and in languages from the same broad family, you had "words" in B, and specific numbers of digits and bits in PL/1. The C authors reacted strongly to "fixed binary 71" and introduced types that were less strongly tied to machine-word sizes. I liked "fixed decimal 6", but hated "fixed binary 71", so C was a step up for me. It's too bad their idea of fixed decimal wasn't Sue's! --dave -- David Collier-Brown, | Always do right. This will gratify System Programmer and Author | some people and astonish the rest davecb-0XdUWXLQalXR7s880joybQ at public.gmane.org | -- Mark Twain (416) 223-8968 -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From waltdnes-SLHPyeZ9y/tg9hUCZPvPmw at public.gmane.org Thu Aug 15 19:32:14 2013 From: waltdnes-SLHPyeZ9y/tg9hUCZPvPmw at public.gmane.org (Walter Dnes) Date: Thu, 15 Aug 2013 15:32:14 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <520B1551.6030101@lijour.net> Message-ID: <20130815193214.GB5989@waltdnes.org> On Wed, Aug 14, 2013 at 10:47:03PM -0400, D. Hugh Redelmeier wrote > | From: Marc Lijour > > | Check this Google Engineer experience of Computer Science in Vietnam: > | https://neil.fraser.name/news/2013/03/16/ > > That got me reading > > I find it impossible to believe "that only 0.5% of people who submit > their resumes for a programming job can pass FizzBuzz." ???? Ridiculous! #!/bin/bash for counter in {1..100} do if [ $(( ${counter} % 15 )) -eq 0 ]; then echo "Fizz-Buzz" elif [ $(( ${counter} % 3 )) -eq 0 ]; then echo "Fizz" elif [ $(( ${counter} % 5 )) -eq 0 ]; then echo "Buzz" else echo ${counter} fi done -- Walter Dnes I don't run "desktop environments"; I run useful applications -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Thu Aug 15 20:25:25 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Thu, 15 Aug 2013 16:25:25 -0400 (EDT) Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: References: Message-ID: | From: David Collier-Brown | Previous to C, and in languages from the same broad family, | you had "words" in B, and specific numbers of digits and bits in PL/1. | | The C authors reacted strongly to "fixed binary 71" and introduced | types that were less strongly tied to machine-word sizes. And yet that is where we've gotten to in C with inttypes.h: you can specify how many bits you need (for three different variants of need: at least, fast, and exactly). What seems better about C (kind of) is that arithmentic is done in crudely quantized widths rather than finely tailored widths. But the problem is pretty much the same: surprising errors due to overflow. I kind of think that integral arithmetic should be evaluated by the compiler in sufficient width that no overflow in intermediate calculations occurs except possibly in the case where the final result is too big for its destination. So in: "longv = intv1 + intv2;" the + would be evaluated in long, not int. But in: "intv = intv1 + intv2;" the + could be evaluated in int. Currently C evaluates intv1 + intv2 in int. The idea of my proposal is that there is no overflow unless the programmer forced it. Where PL/I went badly off the rails was the rule for division. They gave away all the bits to fraction, leaving no room for a carry in subsequent calculations. 8 + 7 / 3 would overflow if I remember correctly. | I liked "fixed decimal 6", but hated "fixed binary 71", so C was a step | up for me. It's too bad their idea of fixed decimal wasn't Sue's! Why? Guess: you think when you care about the base, you care about number-of-digit specs from the "real world" (forms and the like); with binary, you really mean "an integer" and width is a distraction. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From dmason-bqArmZWzea/GcjXNFnLQ/w at public.gmane.org Thu Aug 15 22:41:35 2013 From: dmason-bqArmZWzea/GcjXNFnLQ/w at public.gmane.org (David Mason) Date: Thu, 15 Aug 2013 18:41:35 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: References: Message-ID: On 15 August 2013 16:25, D. Hugh Redelmeier wrote: > I kind of think that integral arithmetic should be evaluated by the > compiler in sufficient width that no overflow in intermediate > calculations occurs That's why I program in Smalltalk or Scheme or something else with proper BigInts - only switching to Java or C if speed is proven to *really* matter. ../Dave -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org Thu Aug 15 22:50:14 2013 From: kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org (Kevin Cozens) Date: Thu, 15 Aug 2013 18:50:14 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <20130815193214.GB5989-SLHPyeZ9y/tg9hUCZPvPmw@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <520B1551.6030101@lijour.net> <20130815193214.GB5989@waltdnes.org> Message-ID: <520D5B26.90508@ve3syb.ca> On 13-08-15 03:32 PM, Walter Dnes wrote: > #!/bin/bash > for counter in {1..100} > do > if [ $(( ${counter} % 15 )) -eq 0 ]; then echo "Fizz-Buzz" > elif [ $(( ${counter} % 3 )) -eq 0 ]; then echo "Fizz" > elif [ $(( ${counter} % 5 )) -eq 0 ]; then echo "Buzz" > else echo ${counter} > fi > done Do you lose points for typos? (Fizz-Buzz instead of FizzBuzz) :) Under Linux Mint 14 which uses dash (instead of bash) as default kernel, the example program doesn't run. sh fizzbuzz.sh fizzbuzz.sh: 4: fizzbuzz.sh: arithmetic expression: expecting primary: " {1..100} % 15 " -- Cheers! Kevin. http://www.ve3syb.ca/ |"Nerds make the shiny things that distract Owner of Elecraft K2 #2172 | the mouth-breathers, and that's why we're | powerful!" #include | --Chris Hardwick -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org Thu Aug 15 22:56:55 2013 From: kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org (Kevin Cozens) Date: Thu, 15 Aug 2013 18:56:55 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <520D5B26.90508-4dS5u2o1hCn3fQ9qLvQP4Q@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <520B1551.6030101@lijour.net> <20130815193214.GB5989@waltdnes.org> <520D5B26.90508@ve3syb.ca> Message-ID: <520D5CB7.6000203@ve3syb.ca> On 13-08-15 06:50 PM, Kevin Cozens wrote: > Under Linux Mint 14 which uses dash (instead of bash) as default kernel, the Speaking of typos... "kernel" should have been "shell". :P -- Cheers! Kevin. http://www.ve3syb.ca/ |"Nerds make the shiny things that distract Owner of Elecraft K2 #2172 | the mouth-breathers, and that's why we're | powerful!" #include | --Chris Hardwick -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From scruss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 16 00:26:25 2013 From: scruss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Stewart C. Russell) Date: Thu, 15 Aug 2013 20:26:25 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: References: Message-ID: <520D71B1.8040701@gmail.com> David Collier-Brown wrote: > > Previous to C, and in languages from the same broad family, > you had "words" in B, and specific numbers of digits and bits in PL/1. There are a surprising number of UK non-computer-science types for whom their first compiled language was one of these C-precursors: BCPL. It was possible to write a particularly tiny compiler for the language, and there were versions for the BBC Micro (6502) and the Amstrad CPC (Z80) which ran from a 16 KB EPROM. It was also the first language taught at Cambridge to all Computer Science students. It later became the source of much ire in the Amiga world, as early (buggy) versions of AmigaDOS were basically the Tripos OS developed at Cambridge, entirely in BCPL. Martin Richards still plugs along with BCPL development. He's written an entire book teaching programming on the Raspberry Pi using BCPL: ?Young Persons Guide to BCPL Programming on the Raspberry Pi? http://www.cl.cam.ac.uk/~mr10/bcpl4raspi.pdf Stewart -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Fri Aug 16 02:33:00 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Thu, 15 Aug 2013 22:33:00 -0400 (EDT) Subject: Intel CPU arcana: Haswell virtualization and Transactional Sychronization together Message-ID: Haswell is the new Intel generation of processors being rolled out over the coming months. As usual, it comes with a few new features. At the TLUG meeting, I was surprised to hear that Intel CPU chips with the new TSX feature would not have the virtualization features (VT-x, VT-d, etc.). This turns out not to be the case. For example, the Intel Core i7-4770 has both That is a top-of-the-line consumer processor As far as I can tell, the i5-4670 is almost the same (no hyperthreading, 6MiB L3 cache instead of 8MiB, slightly slower turbo). And it is quite a bit cheaper. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Fri Aug 16 18:52:13 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Fri, 16 Aug 2013 14:52:13 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <520D71B1.8040701-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> References: <520D71B1.8040701@gmail.com> Message-ID: <20130816185213.GP7306@csclub.uwaterloo.ca> On Thu, Aug 15, 2013 at 08:26:25PM -0400, Stewart C. Russell wrote: > There are a surprising number of UK non-computer-science types for whom > their first compiled language was one of these C-precursors: BCPL. It > was possible to write a particularly tiny compiler for the language, and > there were versions for the BBC Micro (6502) and the Amstrad CPC (Z80) > which ran from a 16 KB EPROM. > > It was also the first language taught at Cambridge to all Computer > Science students. It later became the source of much ire in the Amiga > world, as early (buggy) versions of AmigaDOS were basically the Tripos > OS developed at Cambridge, entirely in BCPL. It may have had bugs, but it sure worked well. I found DOS running a single applications crashed more often than AmigaDOS did multitasking on hardware with no memory protection. It was pretty darn impressive. > Martin Richards still plugs along with BCPL development. He's written an > entire book teaching programming on the Raspberry Pi using BCPL: ?Young > Persons Guide to BCPL Programming on the Raspberry Pi? > http://www.cl.cam.ac.uk/~mr10/bcpl4raspi.pdf -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Fri Aug 16 18:53:34 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Fri, 16 Aug 2013 14:53:34 -0400 Subject: Intel CPU arcana: Haswell virtualization and Transactional Sychronization together In-Reply-To: References: Message-ID: <20130816185334.GQ7306@csclub.uwaterloo.ca> On Thu, Aug 15, 2013 at 10:33:00PM -0400, D. Hugh Redelmeier wrote: > Haswell is the new Intel generation of processors being rolled out over > the coming months. As usual, it comes with a few new features. > > At the TLUG meeting, I was surprised to hear that Intel CPU chips with the > new TSX feature > > would not have the virtualization features (VT-x, VT-d, etc.). > > This turns out not to be the case. For example, the Intel Core i7-4770 > has both > > > That is a top-of-the-line consumer processor > > > > > As far as I can tell, the i5-4670 is almost the same (no hyperthreading, > 6MiB L3 cache instead of 8MiB, slightly slower turbo). And it is quite a > bit cheaper. intel likes to arbitrarily remove features from some models of a chip, even though the die always contains the features. For some reason they think this makes sense. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 16 20:41:53 2013 From: cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Christopher Browne) Date: Fri, 16 Aug 2013 16:41:53 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <20130816185213.GP7306-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> Message-ID: On Fri, Aug 16, 2013 at 2:52 PM, Lennart Sorensen wrote: > On Thu, Aug 15, 2013 at 08:26:25PM -0400, Stewart C. Russell wrote: >> There are a surprising number of UK non-computer-science types for whom >> their first compiled language was one of these C-precursors: BCPL. It >> was possible to write a particularly tiny compiler for the language, and >> there were versions for the BBC Micro (6502) and the Amstrad CPC (Z80) >> which ran from a 16 KB EPROM. >> >> It was also the first language taught at Cambridge to all Computer >> Science students. It later became the source of much ire in the Amiga >> world, as early (buggy) versions of AmigaDOS were basically the Tripos >> OS developed at Cambridge, entirely in BCPL. > > It may have had bugs, but it sure worked well. I found DOS running a > single applications crashed more often than AmigaDOS did multitasking > on hardware with no memory protection. It was pretty darn impressive. Part of that falls from the fact that there were a zillion bizarrely slightly different DOS systems, and hackers that tended to write *horribly* hacky code that would consciously tweak at the differences. If, on AmigaDOS, you were running reasonably cleanly written C-based apps that weren't poking sticks (badly!) at hardware registers all the time, that's going to be a lot more stable. Writing to the screen, on MS-DOS, was a lot worse than it ought to have been :-( -- When confronted by a difficult problem, solve it by reducing it to the question, "How would the Lone Ranger handle this?" -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 16 20:57:24 2013 From: colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Colin McGregor) Date: Fri, 16 Aug 2013 16:57:24 -0400 Subject: Linux in the Park 2013 Message-ID: One other thought that should have been in the announcement: Anyone who has skin like mine (burns fairly easily in sunshine) do remember to bring/use some sunscreen lotion. We are in a fairly well shaded part of the park, but even so, better safe than sorry (or well, burned)... Colin McGregor -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Fri Aug 16 20:58:58 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Fri, 16 Aug 2013 16:58:58 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> Message-ID: <20130816205858.GA12618@csclub.uwaterloo.ca> On Fri, Aug 16, 2013 at 04:41:53PM -0400, Christopher Browne wrote: > Part of that falls from the fact that there were a zillion bizarrely slightly > different DOS systems, and hackers that tended to write *horribly* > hacky code that would consciously tweak at the differences. > > If, on AmigaDOS, you were running reasonably cleanly written C-based > apps that weren't poking sticks (badly!) at hardware registers all the time, > that's going to be a lot more stable. But if you are writing C and get a pointer address messed up, on the Amiga you could take out a different application running since everything was in one memory space. At least on DOS it could only crash the application itself. The fact this rarely happened made me pretty impressed at the quality of code people were producing for the Amiga. > Writing to the screen, on MS-DOS, was a lot worse than it ought to have > been :-( Well that is true. DOS was pretty horrible. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Fri Aug 16 21:01:13 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Fri, 16 Aug 2013 17:01:13 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> Message-ID: <520E9319.7090007@rogers.com> Christopher Browne wrote: > Writing to the screen, on MS-DOS, was a lot worse than it ought to have > been :-( As I recall, writing to the hardware tended to be the norm, because support in DOS was so bad or non-existent. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Fri Aug 16 21:02:47 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Fri, 16 Aug 2013 17:02:47 -0400 Subject: Semi-OT: Why Kids Can't use Computers In-Reply-To: <520D5B26.90508-4dS5u2o1hCn3fQ9qLvQP4Q@public.gmane.org> References: <000901ce97a0$a50039a0$ef00ace0$@net> <52099324.1020205@rogers.com> <20130813175348.GG7306@csclub.uwaterloo.ca> <000001ce98ab$4aae75a0$e00b60e0$@net> <520B1551.6030101@lijour.net> <20130815193214.GB5989@waltdnes.org> <520D5B26.90508@ve3syb.ca> Message-ID: <20130816210247.GB12618@csclub.uwaterloo.ca> On Thu, Aug 15, 2013 at 06:50:14PM -0400, Kevin Cozens wrote: > On 13-08-15 03:32 PM, Walter Dnes wrote: > > #!/bin/bash > > for counter in {1..100} > > do > > if [ $(( ${counter} % 15 )) -eq 0 ]; then echo "Fizz-Buzz" > > elif [ $(( ${counter} % 3 )) -eq 0 ]; then echo "Fizz" > > elif [ $(( ${counter} % 5 )) -eq 0 ]; then echo "Buzz" > > else echo ${counter} > > fi > > done > > Do you lose points for typos? (Fizz-Buzz instead of FizzBuzz) :) > > Under Linux Mint 14 which uses dash (instead of bash) as default kernel, the > example program doesn't run. > > sh fizzbuzz.sh > fizzbuzz.sh: 4: fizzbuzz.sh: arithmetic expression: expecting primary: " > {1..100} % 15 " That is a user error. The #! line explicitly said /bin/bash, so you screwed up by using sh. If you had done chmod a+x on it, and then run it, it would have worked fine, no matter what sh is. -- len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Fri Aug 16 21:12:14 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Fri, 16 Aug 2013 17:12:14 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <20130816205858.GA12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> Message-ID: <520E95AE.6010201@rogers.com> Lennart Sorensen wrote: > Well that is true. DOS was pretty horrible. A lot of people don't know that it was originally written as a development system for a hardware manufacturer. Seattle Computer Products, a manufacture of S-100 bus hardware, created it for testing new boards, while waiting for CP/M-86 to be released. BG then bought it, after he had already sold it to IBM. It was originally called QDOS, for Quick and Dirty Operating System. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Fri Aug 16 22:06:38 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Fri, 16 Aug 2013 18:06:38 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <520E95AE.6010201-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> Message-ID: <20130816220638.GC12618@csclub.uwaterloo.ca> On Fri, Aug 16, 2013 at 05:12:14PM -0400, James Knott wrote: > A lot of people don't know that it was originally written as a > development system for a hardware manufacturer. Seattle Computer > Products, a manufacture of S-100 bus hardware, created it for testing > new boards, while waiting for CP/M-86 to be released. BG then bought > it, after he had already sold it to IBM. It was originally called QDOS, > for Quick and Dirty Operating System. Yeah, it's amazing we are stuck with the legacy of so many bad decisions. IBM considered the m68k, but decided that the board would cost to much compared to the 8088 (even the 8086 requiring a 16bit bus was considered to cost too much). Of course the Mac, Amiga and Atari ST all went on to use the m68k, as did the Sun 3, HP 7xx, Apollo, and NeXT among many others. Amazing how a CPU that everyone used lost out to the one only one type of machine used. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From waltdnes-SLHPyeZ9y/tg9hUCZPvPmw at public.gmane.org Fri Aug 16 23:15:26 2013 From: waltdnes-SLHPyeZ9y/tg9hUCZPvPmw at public.gmane.org (Walter Dnes) Date: Fri, 16 Aug 2013 19:15:26 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <520E9319.7090007-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <520E9319.7090007@rogers.com> Message-ID: <20130816231526.GC30183@waltdnes.org> On Fri, Aug 16, 2013 at 05:01:13PM -0400, James Knott wrote > Christopher Browne wrote: > > Writing to the screen, on MS-DOS, was a lot worse than it ought to have > > been :-( > > As I recall, writing to the hardware tended to be the norm, because > support in DOS was so bad or non-existent. There were 2 "fully supported" alternatives to poking bytes directly to the screen. The problem is that they were painfully slow, especially on an under-powered 8088. The first alternative was writing to screen via BIOS calls. It was definitely slower than direct pokes. The other alternative was writing to screen and positioning the cursor using ANSI escape sequences. BIOS was "slow", ANSI was "slowest". -- Walter Dnes I don't run "desktop environments"; I run useful applications -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From opengeometry-FFYn/CNdgSA at public.gmane.org Sat Aug 17 00:23:35 2013 From: opengeometry-FFYn/CNdgSA at public.gmane.org (William Park) Date: Fri, 16 Aug 2013 20:23:35 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <20130816220638.GC12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> Message-ID: <20130817002335.GA24896@node1.localdomain> On Fri, Aug 16, 2013 at 06:06:38PM -0400, Lennart Sorensen wrote: > On Fri, Aug 16, 2013 at 05:12:14PM -0400, James Knott wrote: > > A lot of people don't know that it was originally written as a > > development system for a hardware manufacturer. Seattle Computer > > Products, a manufacture of S-100 bus hardware, created it for testing > > new boards, while waiting for CP/M-86 to be released. BG then bought > > it, after he had already sold it to IBM. It was originally called QDOS, > > for Quick and Dirty Operating System. > > Yeah, it's amazing we are stuck with the legacy of so many bad decisions. > > IBM considered the m68k, but decided that the board would cost to much > compared to the 8088 (even the 8086 requiring a 16bit bus was considered > to cost too much). Of course the Mac, Amiga and Atari ST all went > on to use the m68k, as did the Sun 3, HP 7xx, Apollo, and NeXT among > many others. Amazing how a CPU that everyone used lost out to the one > only one type of machine used. Yeah, this is where "Beta" won (vs. VHS). :-) -- William -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Sat Aug 17 02:02:04 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Fri, 16 Aug 2013 22:02:04 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <20130817002335.GA24896-+21/tKCbORjP0Z7Jsv878P8+0UxHXcjY@public.gmane.org> References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> Message-ID: <520ED99C.3040902@rogers.com> William Park wrote: > Yeah, this is where "Beta" won (vs. VHS). :-) Not quite. As originally marketed, VHS could record 2 hours on a cassette, but Beta only 1. Also, Sony had more expensive licensing terms. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From scruss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Sat Aug 17 18:59:16 2013 From: scruss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Stewart C. Russell) Date: Sat, 17 Aug 2013 14:59:16 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <20130816205858.GA12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> Message-ID: <520FC804.6050605@gmail.com> On 13-08-16 04:58 PM, Lennart Sorensen wrote: > > ... The fact this rarely happened made me pretty impressed at the > quality of code people were producing for the Amiga. Most of the stability was if you stuck with the AmigaDos routines, which were already quite refined from 10-15 years of deployment as Cambridge/Metacomco Tripos. Once you started hitting Commodore's code, things could go sideways fast. I do remember people griping that AmigaDos interfacing needed a lot of casting to BCPL types. All that went away with 2.0, where they expunged the whole BCPL framework. Gone too was the Global Vector, a kind of unprotected (!) shared memory that all BCPL systems had, where you could pass data between processes, as long as you agreed on the addressing and data structure. I don't think this got much use on the Amiga. Stewart -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Sun Aug 18 13:46:05 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Sun, 18 Aug 2013 09:46:05 -0400 (EDT) Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <20130817002335.GA24896-+21/tKCbORjP0Z7Jsv878P8+0UxHXcjY@public.gmane.org> References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> Message-ID: | From: William Park | On Fri, Aug 16, 2013 at 06:06:38PM -0400, Lennart Sorensen wrote: | > Yeah, it's amazing we are stuck with the legacy of so many bad decisions. | > | > IBM considered the m68k, but decided that the board would cost to much | > compared to the 8088 (even the 8086 requiring a 16bit bus was considered | > to cost too much). Of course the Mac, Amiga and Atari ST all went | > on to use the m68k, as did the Sun 3, HP 7xx, Apollo, and NeXT among | > many others. Amazing how a CPU that everyone used lost out to the one | > only one type of machine used. To give it credit, the 8086 came out LONG before the 68000. Apparently it was good enough. (Don't believe published "dates of introduction". says that the 68000 was introduced in 1979 but I got an XC68000 (engineering sample, before normal production) in 1981.) As a compiler writer, I didn't think generating code for any 8-bit processor made sense -- hand-coded assembly code would be too much better. The 6809 was getting there. The 8086 was good enough to compile code for. At least in the small model, all that was needed initially. The 68k was much more expensive. In fact the package was astonishing when it came out: I'd never had a 64-pin DIP before. The next generation was interesting too. The 80286 had a decent on-board MMU (no paging); almost no sytem ended up using that during the chip's useful lifetime. The 68020 (later) had a not-so-great optional separate MMU chip so Sun built their own. When I bought my Atari ST (very new at the time) with a 68000 CPU, I almost bought a cheap Taiwanese clone PC/AT instead (also new at the time) with a i80286. The MMU on the AT's 286 meant Unix could run reasonably on it whereas the ST had no MMU. The PC came with a hard drive for about the same price as the ST with only floppies. (The ST did have circuitry called an MMU. It did nothing like what we think of as an MMU, but it did one great thing: it prevented user programs storing into 0, thus catching most writes through NULL pointers.) So: dirt cheap mass-market 286 systems came out about the same time as cheap 68000 systems. Comparing 8086 with 68000 isn't completely fair due to the different introduction dates. | Yeah, this is where "Beta" won (vs. VHS). :-) ? Intel's instruction set architecture was inferior to Motorola's. Not so clear about everything else, which does tend to matter. The 386 instruction set was as clean as the 68k. Beta was supposed to be better than VHS. As an early adopter of VHS, I don't actually agree. My first VCR (~$1400!) could record 6 hours, had extra heads with a different gap to record that in reasonable quality, and recorded HiFi audio in the helically scanned signal. Beta couldn't touch that at the time. Of course each format leap-frogged, until Beta stopped bothering. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Sun Aug 18 15:25:25 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Sun, 18 Aug 2013 11:25:25 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> Message-ID: <5210E765.2030401@rogers.com> D. Hugh Redelmeier wrote: > My first VCR (~$1400!) could record 6 hours, > had extra heads with a different gap to record that in reasonable > quality, and recorded HiFi audio in the helically scanned signal. > Beta couldn't touch that at the time. Of course each format > leap-frogged, until Beta stopped bothering. By the time HiFi audio was introduced, the "war" was already long won by VHS. The essential factor for users was longer tape time (originally 1 hour for Beta vs 2 for VHS. The difference for manufacturers was the higher licence costs for Beta vs VHS. So, we soon saw a lot more brands selling VHS than Beta. My first VCR was also $1400 and among the first of the 2nd generation that supported 6 hours and had electronic, rather than mechanical control. However, it only had 2 heads, which were optimized for the 6 hour mode. There was a more expensive model that had 4 heads. Of course, those recorders still used linear audio and the remotes were connected via a long cable. The VCR could have up to 14 channels available, with thumb wheels used to tune in each of the 14 choices. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Sun Aug 18 16:42:53 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Sun, 18 Aug 2013 12:42:53 -0400 (EDT) Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <5210E765.2030401-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <5210E765.2030401@rogers.com> Message-ID: | From: James Knott | | D. Hugh Redelmeier wrote: | > My first VCR (~$1400!) could record 6 hours, | > had extra heads with a different gap to record that in reasonable | > quality, and recorded HiFi audio in the helically scanned signal. | > Beta couldn't touch that at the time. Of course each format | > leap-frogged, until Beta stopped bothering. | | By the time HiFi audio was introduced, the "war" was already long won by | VHS. The essential factor for users was longer tape time (originally 1 | hour for Beta vs 2 for VHS. The difference for manufacturers was the | higher licence costs for Beta vs VHS. So, we soon saw a lot more brands | selling VHS than Beta. | | My first VCR was also $1400 and among the first of the 2nd generation | that supported 6 hours and had electronic, rather than mechanical | control. However, it only had 2 heads, which were optimized for the 6 | hour mode. There was a more expensive model that had 4 heads. Of | course, those recorders still used linear audio and the remotes were | connected via a long cable. The VCR could have up to 14 channels | available, with thumb wheels used to tune in each of the 14 choices. You are quite right. I was conflating two memories. My first VCR was a JVC HR-6700u. Audio was in the linear track. This model came out a few months after the first VCRs with 6-hour mode (RCA?). It was the first 4-head model (two heads for 2-hour mode and two heads for 6 hour mode; 4-hour mode worked but not as well). It had a feature that I thought would be useful, but was horrible: it could play back the recording at faster-than-realtime speeds and adjust the pitch of the playback. Unfortunately the resulting sound was horrible. It had mechanical keys and a wired remote. If I remember correctly, this was in 1979 (I bought it through a non-retail channel before CSA aproval (Hydro aproved)). -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Sun Aug 18 18:46:00 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Sun, 18 Aug 2013 14:46:00 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <5210E765.2030401@rogers.com> Message-ID: <52111668.8000509@rogers.com> D. Hugh Redelmeier wrote: > My first VCR was a JVC HR-6700u. Audio was in the linear track. This > model came out a few months after the first VCRs with 6-hour mode > (RCA?). Mine was an RCA and, as I mentioned, did 6 hours. There were similar models from Panasonic, Sylvania & Quasar, all manufactured by Matsushita. I also got mine in 1979. After a bit of Googling, I found the model I bought in the fall of 1979. http://www.ebay.com/itm/RCA-SELECTAVISION-CASSETTE-RECORDER-VET-450-WITH-REMOTE-/181196777789 -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From sciguy-Ja3L+HSX0kI at public.gmane.org Mon Aug 19 03:23:39 2013 From: sciguy-Ja3L+HSX0kI at public.gmane.org (Paul King) Date: Sun, 18 Aug 2013 23:23:39 -0400 Subject: Barely functioning HD, and seeking advice re: how to successfully record in blu-ray Message-ID: <000301ce9c8b$80112ec0$80338c40$@net> The 1TB Seagate I had been using and trying to recover data from is being officially declared "pooched". The Linux partitions on it which I thought were viable were not upon closer examination. Nearly all files and directories were missing below the root level of any partition I looked at. I thought that it may be the external HD connection that was the problem. It was connected with a housing that was a SATA/EIDE hybrid, so I just used one which was pure SATA. No luck there either. The ddrescue program produced a 3GB file which is not mountable, and yes I used "-o loop". 3GB out of half of a terabyte is not much, but it is easily enough for email. The file has been kept, but at present it is pretty much taking up space. While I give out an enormous thanks for Hugh's advice and encouragement, I think that I need to move on. Most things can be recovered from existing DVDs and CDs I have around, except they too are slowly succumbing to bit-rot. My personal email must now be declared "forever lost". Luckily I have an LG Blu-Ray USB external drive with a Windows-based burner that promises to back things onto fresh media. Except that I have had a hard time with this. Of 6 BD disks that spent several minutes in the bay with the progress bar doing nothing, only to return a "burn failed" error, one may have been successful. This is far worse a success record than when DVD burning first came out. Since these are my first experiences with recording on to BD media, I don't know if this is expected or not. Is anyone able to suggest the conditions which will optimize the chances for a successful burn? This is for files on an entertainment center which is single-boot, unless you know of "live" distros which have k3b or something similar. Meatime, I just thought of going back to my Partition Magic (Slackware) DVD to see if anything useful is there. Paul King -------------- next part -------------- An HTML attachment was scrubbed... URL: From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Mon Aug 19 04:59:59 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Mon, 19 Aug 2013 00:59:59 -0400 (EDT) Subject: Barely functioning HD, and seeking advice re: how to successfully record in blu-ray In-Reply-To: <000301ce9c8b$80112ec0$80338c40$@net> References: <000301ce9c8b$80112ec0$80338c40$@net> Message-ID: | From: Paul King (I've reformatted your message because it arrived rather broken up.) | The 1TB Seagate I had been using and trying to recover data from is | being officially declared "pooched". Sad. Lot of disk stories end like that :-( | The ddrescue program produced a 3GB file which is not mountable, and yes | I used "-o loop". 3GB out of half of a terabyte is not much, but it is | easily enough for email. The file has been kept, but at present it is | pretty much taking up space. There are ways to sift for goodies without looking treating it as a file system. Of course the chances of your valuable bits being in the 1/1000th of the disk that you've got are small. If what you want is mail, you could spend some time sniffing the corpse with a low tech: strings -n 20 imagefile | less | While I give out an enormous thanks for Hugh's advice and encouragement, | I think that I need to move on. Likely wise. | Most things can be recovered from | existing DVDs and CDs I have around, except they too are slowly | succumbing to bit-rot. My personal email must now be declared "forever | lost". This bit-rot scares me. I've been nervous about most affordable backup techniques. So I don't do backups :-) :-) I recommend (superstitiously) to do backups on different media, expecting them to have different failure modes: - hard disks are cheap these days. But losing 3T of backup may lose a lot of backups! - I've had iffy second-hand experience with DVDs - I feel most comfortable (not very comfortable) with CDs. - I really don't trust USB flash drives. They might be useful. - for really important long-term stuff, paper is pretty good (low acid is a good idea; laser toner is probably pretty stable, unlike inkjet) I think that the key is to be very careful about the stuff that matters. That turns out to be very low volume. I mostly want to save human keystrokes rather than megabytes of software. Easier said than done. Annecdote: I remember discovering that my backup CDs were wrecked after some years by the plastic window in the CD envelope welding itself the the CD! There are many failure modes. It only takes one to get you. | Luckily I have an LG Blu-Ray USB external drive with a Windows-based | burner that promises to back things onto fresh media. Except that I have | had a hard time with this. | | Of 6 BD disks that spent several minutes in the bay with the progress | bar doing nothing, only to return a "burn failed" error, one may have | been successful. This is far worse a success record than when DVD | burning first came out. Since these are my first experiences with | recording on to BD media, I don't know if this is expected or not. | | Is anyone able to suggest the conditions which will optimize the chances | for a successful burn? This is for files on an entertainment center | which is single-boot, unless you know of "live" distros which have k3b | or something similar. Meatime, I just thought of going back to my | Partition Magic (Slackware) DVD to see if anything useful is there. I've bought a BLuRay burner (SATA) and will eventually install it. One trouble is that I suspect that BluRay will be no more reliable than DVD. One reason that I bought the drive was that it also burns a new kind of archival DVDs (Millenniata M-Disk). I don't actually know how good M-Disks are; they are not cheap. The chatter about burning BluRays under Linux looks worisome. As usual, cdrecord folks slag the forkers. For previous fights, I've found the cdrecord proponents quite over-the-top. They may well be right this time. Anyway, blank BluRays are a similar cost/byte as hard drives: BluRay: one 25G disk for $1 (may not be the best brand; what is the best brand?). Hard drive: 3T USB 3.0 external for $109 most weekends ($90 last boxing day; may not be the best brand). Hard drives are a lot easier to deal with. But a lot more eggs in one basket. I've worried that a decent external BluRay drive ought to be USB3.0 vs USB2.0. But I haven't done the bandwidth math. Lennart has often pointed out that USB2 is very CPU-intensive. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Mon Aug 19 05:19:24 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Mon, 19 Aug 2013 01:19:24 -0400 (EDT) Subject: bargain? 13.3" ultrabook with 1920x1080 for $600 (today only) Message-ID: ($1100 at Best Buy) ZENBOOK Prime UX31A-DH51-CA w/ Core i5-3317U, 4GB, 128GB SSD, 13.3in FHD, Win 8 64-bit. What I like: - good resolution; lowest price I've seen for a notebook with this resolution. IPS technology is very nice. - OK size SSD. - low-power i5 is a nice choice. What could be better: - this is last year's chip. Th Haswell series (this years) uses less power - no touchscreen. The future! - 4G RAM is a bit low these days and in the future. Probably not expandable. I just assume that Linux will run this well. I could be wrong. I'm tempted, but my 5-year-old ThinkPad x61t isn't that bad (12 inch 1400x1050 screen; upgraded to 4G of ram and 120G of SSD). -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org Mon Aug 19 07:41:08 2013 From: kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org (Kevin Cozens) Date: Mon, 19 Aug 2013 03:41:08 -0400 Subject: Barely functioning HD, and seeking advice re: how to successfully record in blu-ray In-Reply-To: <000301ce9c8b$80112ec0$80338c40$@net> References: <000301ce9c8b$80112ec0$80338c40$@net> Message-ID: <5211CC14.5040806@ve3syb.ca> On 13-08-18 11:23 PM, Paul King wrote: > The 1TB Seagate I had been using and trying to recover data from is > being officially declared ?pooched?. > > The Linux partitions on it which I thought were viable were not upon > closer examination. Nearly all files and directories were missing below > the root level of any partition I looked at. Was the drive in such a bad shape that even using the alternate superblocks was not of any help in recovering data on the drives? -- Cheers! Kevin. http://www.ve3syb.ca/ |"Nerds make the shiny things that distract Owner of Elecraft K2 #2172 | the mouth-breathers, and that's why we're | powerful!" #include | --Chris Hardwick -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From sciguy-Lmt0BfyYGMw at public.gmane.org Mon Aug 19 08:40:02 2013 From: sciguy-Lmt0BfyYGMw at public.gmane.org (sciguy-Lmt0BfyYGMw at public.gmane.org) Date: Mon, 19 Aug 2013 04:40:02 -0400 Subject: Barely functioning HD, and seeking advice re: how to successfully record in blu-ray In-Reply-To: <5211CC14.5040806-4dS5u2o1hCn3fQ9qLvQP4Q@public.gmane.org> References: <000301ce9c8b$80112ec0$80338c40$@net> <5211CC14.5040806@ve3syb.ca> Message-ID: I am using a live DVD for my rescue efforts, since the entertainment center is single-boot (W7). The live Linux I am using is a Slackware variant called "Partition Magic". You can Google it like I did. Right now, PM is running entirely in RAM, which certainly makes it run faster. :-) "fsck.ext4 -b" expects me to specify an alternate superblock. I don't know what to place there. At any rate, while I recall the error from fsck being "can't find superblock", I am also getting I/O errors any time I do anything to access the drive using fdisk. So, I am suspecting that there is a general hardware failure (as the fdisk error messages suggest, which I had been ignoring). Paul > On 13-08-18 11:23 PM, Paul King wrote: >> The 1TB Seagate I had been using and trying to recover data from is >> being officially declared ?pooched?. >> >> The Linux partitions on it which I thought were viable were not upon >> closer examination. Nearly all files and directories were missing below >> the root level of any partition I looked at. > > Was the drive in such a bad shape that even using the alternate > superblocks > was not of any help in recovering data on the drives? > -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org Mon Aug 19 13:24:58 2013 From: jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org (Jamon Camisso) Date: Mon, 19 Aug 2013 09:24:58 -0400 Subject: bargain? 13.3" ultrabook with 1920x1080 for $600 (today only) In-Reply-To: References: Message-ID: <52121CAA.5060907@utoronto.ca> On 19/08/13 01:19 AM, D. Hugh Redelmeier wrote: > > > ($1100 at Best Buy) > > ZENBOOK Prime UX31A-DH51-CA w/ Core i5-3317U, 4GB, 128GB SSD, 13.3in FHD, > Win 8 64-bit. > > What I like: > > - good resolution; lowest price I've seen for a notebook with this > resolution. IPS technology is very nice. > > - OK size SSD. > > - low-power i5 is a nice choice. > > > What could be better: > > - this is last year's chip. Th Haswell series (this years) uses less > power > > - no touchscreen. The future! > > - 4G RAM is a bit low these days and in the future. Probably not > expandable. > > > I just assume that Linux will run this well. I could be wrong. > > I'm tempted, but my 5-year-old ThinkPad x61t isn't that bad (12 inch > 1400x1050 screen; upgraded to 4G of ram and 120G of SSD). I have that same thinkpad, last of the 1400x1050 and upgraded to 8GB with the SSD. Now it runs the microcontrollers at my brewery. I am typing this on the first generation UX31 from (1600x900) and really like it still. The battery life is amazing, everything works with Linux. Too bad about the 4GB of RAM yeah, but I run anything demanding on my desktop or on a server with RAM to spare. I highly recommend the UXxx series if you want a portable and compatible Linux ultrabook. Jamon -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From tisdall-DXT9u3ndKiSh7up9GtFB90EOCMrvLtNR at public.gmane.org Mon Aug 19 13:32:34 2013 From: tisdall-DXT9u3ndKiSh7up9GtFB90EOCMrvLtNR at public.gmane.org (Tim Tisdall) Date: Mon, 19 Aug 2013 09:32:34 -0400 Subject: bargain? 13.3" ultrabook with 1920x1080 for $600 (today only) In-Reply-To: <52121CAA.5060907-H217xnMUJC0sA/PxXw9srA@public.gmane.org> References: <52121CAA.5060907@utoronto.ca> Message-ID: Looks like it's sold out. On Mon, Aug 19, 2013 at 9:24 AM, Jamon Camisso wrote: > On 19/08/13 01:19 AM, D. Hugh Redelmeier wrote: > > > > > > ($1100 at Best Buy) > > > > ZENBOOK Prime UX31A-DH51-CA w/ Core i5-3317U, 4GB, 128GB SSD, 13.3in FHD, > > Win 8 64-bit. > > > > What I like: > > > > - good resolution; lowest price I've seen for a notebook with this > > resolution. IPS technology is very nice. > > > > - OK size SSD. > > > > - low-power i5 is a nice choice. > > > > > > What could be better: > > > > - this is last year's chip. Th Haswell series (this years) uses less > > power > > > > - no touchscreen. The future! > > > > - 4G RAM is a bit low these days and in the future. Probably not > > expandable. > > > > > > I just assume that Linux will run this well. I could be wrong. > > > > I'm tempted, but my 5-year-old ThinkPad x61t isn't that bad (12 inch > > 1400x1050 screen; upgraded to 4G of ram and 120G of SSD). > > I have that same thinkpad, last of the 1400x1050 and upgraded to 8GB > with the SSD. Now it runs the microcontrollers at my brewery. > > I am typing this on the first generation UX31 from (1600x900) and really > like it still. The battery life is amazing, everything works with Linux. > Too bad about the 4GB of RAM yeah, but I run anything demanding on my > desktop or on a server with RAM to spare. > > I highly recommend the UXxx series if you want a portable and compatible > Linux ultrabook. > > Jamon > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -------------- next part -------------- An HTML attachment was scrubbed... URL: From stimur-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Mon Aug 19 15:31:08 2013 From: stimur-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Tim Sattarov) Date: Mon, 19 Aug 2013 11:31:08 -0400 Subject: Barely functioning HD, and seeking advice re: how to successfully record in blu-ray In-Reply-To: <000301ce9c8b$80112ec0$80338c40$@net> References: <000301ce9c8b$80112ec0$80338c40$@net> Message-ID: On Sun, Aug 18, 2013 at 11:23 PM, Paul King wrote: > [...] > > The ddrescue program produced a 3GB file which is not mountable, and yes I used > ?-o loop?. 3GB out of half of a terabyte is not much, but it is easily enough for email. > The file has been kept, but at present it is pretty much taking up space. > > > a couple of silly questions:- - did you try dd with noerror option ? - are you doing whole disk image or partition image ? - if yes (the whole disk) did you use offset option for loop mount ? kpartx utility can help you in detecting partitions and offsets (regardless its name it is not KDE or even X application) It could sound strange, but since some hard drive chipset becomes very hot during intensive read, you'll need intensive cooling. I saw (and did it myself) recommendations to freeze hard drive (e.g. in a fridge) before rescuing data. http://lifehacker.com/5515337/save-a-failed-hard-drive-in-your-freezer-redux Tim -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Mon Aug 19 15:48:22 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Mon, 19 Aug 2013 11:48:22 -0400 (EDT) Subject: Barely functioning HD, and seeking advice re: how to successfully record in blu-ray In-Reply-To: References: <000301ce9c8b$80112ec0$80338c40$@net> Message-ID: | From: Tim Sattarov | a couple of silly questions:- | - did you try dd with noerror option ? He used ddrescue, which is even better. | kpartx utility can help you in detecting partitions and offsets | (regardless its name it is not KDE or even X application) Good to know. | It could sound strange, but since some hard drive chipset becomes very | hot during intensive read, you'll need intensive cooling. | I saw (and did it myself) recommendations to freeze hard drive (e.g. | in a fridge) before rescuing data. | | http://lifehacker.com/5515337/save-a-failed-hard-drive-in-your-freezer-redux Interesting. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From stimur-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Mon Aug 19 16:05:39 2013 From: stimur-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Tim Sattarov) Date: Mon, 19 Aug 2013 12:05:39 -0400 Subject: Barely functioning HD, and seeking advice re: how to successfully record in blu-ray In-Reply-To: References: <000301ce9c8b$80112ec0$80338c40$@net> Message-ID: On Mon, Aug 19, 2013 at 11:48 AM, D. Hugh Redelmeier wrote: > Interesting. actually, I found better explanation why could it help: http://superuser.com/questions/353910/why-does-freezing-your-hard-drive-sometimes-help-to-recover-data-technical-deta Tim -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Mon Aug 19 20:44:55 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Mon, 19 Aug 2013 16:44:55 -0400 Subject: Barely functioning HD, and seeking advice re: how to successfully record in blu-ray In-Reply-To: References: <000301ce9c8b$80112ec0$80338c40$@net> Message-ID: <20130819204455.GD12618@csclub.uwaterloo.ca> On Mon, Aug 19, 2013 at 12:59:59AM -0400, D. Hugh Redelmeier wrote: > Sad. Lot of disk stories end like that :-( I hate disk failures, and always use RAID 1 when I build a machine. Not a substitute for backups, just saves a lot of grief. > I've bought a BLuRay burner (SATA) and will eventually install it. One > trouble is that I suspect that BluRay will be no more reliable than > DVD. One reason that I bought the drive was that it also > burns a new kind of archival DVDs (Millenniata M-Disk). I don't > actually know how good M-Disks are; they are not cheap. > > The chatter about burning BluRays under Linux looks worisome. As > usual, cdrecord folks slag the forkers. For previous fights, I've > found the cdrecord proponents quite over-the-top. They may well be > right this time. Hmm, I haven't tried it yet (although I have a blu-ray drive in one of my machines). I was thinking growisofs would be the tool to use. Not sure. > Anyway, blank BluRays are a similar cost/byte as hard drives: > > BluRay: one 25G disk for $1 (may not be the best brand; what is the > best brand?). > > Hard drive: 3T USB 3.0 external for $109 most weekends ($90 last > boxing day; may not be the best brand). So get two and store two copies in different locations. > Hard drives are a lot easier to deal with. But a lot more eggs in one > basket. Hence solution: Two baskets. > I've worried that a decent external BluRay drive ought to be USB3.0 vs > USB2.0. But I haven't done the bandwidth math. Lennart has often > pointed out that USB2 is very CPU-intensive. USB3 on the other hand is amazing. I just replaced the 500GB drive in my laptop with a 1TB this weekend. It had 325GB of data on it, and it took about 30 minutes to clone from the internal 500GB to the new 1TB in a USB3 enclosure. I was having a hard time believing the estimate it gave. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Mon Aug 19 20:47:57 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Mon, 19 Aug 2013 16:47:57 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <20130816231526.GC30183-SLHPyeZ9y/tg9hUCZPvPmw@public.gmane.org> References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <520E9319.7090007@rogers.com> <20130816231526.GC30183@waltdnes.org> Message-ID: <20130819204757.GE12618@csclub.uwaterloo.ca> On Fri, Aug 16, 2013 at 07:15:26PM -0400, Walter Dnes wrote: > There were 2 "fully supported" alternatives to poking bytes directly > to the screen. The problem is that they were painfully slow, especially > on an under-powered 8088. The first alternative was writing to screen > via BIOS calls. It was definitely slower than direct pokes. The other > alternative was writing to screen and positioning the cursor using ANSI > escape sequences. BIOS was "slow", ANSI was "slowest". Of course it was. ANSI.SYS was a DOS extention, so you were writing to ANSI.SYS which then would write to the BIOS. Yet another layer of abstraction. Of course it wasn't going to be faster than going direct to the video BIOS. Now if ANSI.SYS had known how to directly talk to the video hardware, then it could have been faster perhaps. I don't recall ever seeing any optimized versions of ANSI.SYS for VGA cards specificly. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Mon Aug 19 20:50:45 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Mon, 19 Aug 2013 16:50:45 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <20130817002335.GA24896-+21/tKCbORjP0Z7Jsv878P8+0UxHXcjY@public.gmane.org> References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> Message-ID: <20130819205045.GF12618@csclub.uwaterloo.ca> On Fri, Aug 16, 2013 at 08:23:35PM -0400, William Park wrote: > Yeah, this is where "Beta" won (vs. VHS). :-) It seems long term VHS still won. m68k (Beta) may have won more designs, but x86 (VHS) won the quantity war. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Mon Aug 19 20:56:18 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Mon, 19 Aug 2013 16:56:18 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> Message-ID: <20130819205618.GG12618@csclub.uwaterloo.ca> On Sun, Aug 18, 2013 at 09:46:05AM -0400, D. Hugh Redelmeier wrote: > To give it credit, the 8086 came out LONG before the 68000. > Apparently it was good enough. > > (Don't believe published "dates of introduction". > says that the 68000 was > introduced in 1979 but I got an XC68000 (engineering sample, before normal > production) in 1981.) > > As a compiler writer, I didn't think generating code for any 8-bit > processor made sense -- hand-coded assembly code would be too much better. > The 6809 was getting there. > > The 8086 was good enough to compile code for. At least in the small > model, all that was needed initially. > > The 68k was much more expensive. In fact the package was astonishing > when it came out: I'd never had a 64-pin DIP before. Yes that chip is quite big. > The next generation was interesting too. The 80286 had a decent on-board > MMU (no paging); almost no sytem ended up using that during the chip's > useful lifetime. The 68020 (later) had a not-so-great optional separate > MMU chip so Sun built their own. I thought OS/2 made use of it. > When I bought my Atari ST (very new at the time) with a 68000 CPU, I > almost bought a cheap Taiwanese clone PC/AT instead (also new at the time) > with a i80286. The MMU on the AT's 286 meant Unix could run reasonably on > it whereas the ST had no MMU. The PC came with a hard drive for about the > same price as the ST with only floppies. > > (The ST did have circuitry called an MMU. It did nothing like what we > think of as an MMU, but it did one great thing: it prevented user > programs storing into 0, thus catching most writes through NULL pointers.) > > So: dirt cheap mass-market 286 systems came out about the same time as > cheap 68000 systems. Comparing 8086 with 68000 isn't completely fair > due to the different introduction dates. But they were being considered for a new design at the same time. So I think the comparison is fair. > | Yeah, this is where "Beta" won (vs. VHS). :-) > > ? > > Intel's instruction set architecture was inferior to Motorola's. Not > so clear about everything else, which does tend to matter. The 386 > instruction set was as clean as the 68k. I have written MMU code for the 386. What a mess. I must admit I have never looked at the MMU code for the 68k series (after all they didn't have it until the 68020 with the optional MMU). They are both very much CISC. I think these days ARM and PowerPC are much nicer to work with. > Beta was supposed to be better than VHS. As an early adopter of VHS, I > don't actually agree. My first VCR (~$1400!) could record 6 hours, > had extra heads with a different gap to record that in reasonable > quality, and recorded HiFi audio in the helically scanned signal. > Beta couldn't touch that at the time. Of course each format > leap-frogged, until Beta stopped bothering. Well they did keep trying to make VHS better. The multiple heads did help. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Tue Aug 20 02:48:29 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Mon, 19 Aug 2013 22:48:29 -0400 (EDT) Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <20130819205618.GG12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> Message-ID: | From: Lennart Sorensen | On Sun, Aug 18, 2013 at 09:46:05AM -0400, D. Hugh Redelmeier wrote: | > The next generation was interesting too. The 80286 had a decent on-board | > MMU (no paging); almost no sytem ended up using that during the chip's | > useful lifetime. The 68020 (later) had a not-so-great optional separate | > MMU chip so Sun built their own. | | I thought OS/2 made use of it. The 386 was introduced in 1985. PCs using it came out in 1986. OS/2 was first released in December 1987, but probably wasn't useful (text mode only, ...). Released a year later, 1.1 had a GUI. So if you wanted to run OS/2, you probably had a 386. It would happily run as a 286. Most 386s spent their lives emulating 8086s and perhaps 80286s. PC hardware was cutting edge because that was where the competition was. PC operating systems were real lagards because there was no competition. I realize that word is ambiguous. There certainly were a reasonable number of competing OSes (i.e. competition) but the actual struggle was so one-sided that it didn't appear to be a competition. Reasonable choices of OS for PCs over the years. - DOS - From Digital Research: CP/M 86, MP/M (multitasking version), DrDOS - UCSD Pascal - various genuine UNIXes (quite a few good ones once the 386 came out). Xenix worked well on 286s (I ran it on an 8086). - UNIX clones: Coherent, Whitesmith's Idris, Minix, and others I've forgotten - BeOS - modern UNIXes: *BSD, Linux, OSX, Solaris | > So: dirt cheap mass-market 286 systems came out about the same time as | > cheap 68000 systems. Comparing 8086 with 68000 isn't completely fair | > due to the different introduction dates. | | But they were being considered for a new design at the same time. | So I think the comparison is fair. After the 68000 became viable, when was an 8088 considered for a new design of a personal computer that was not meant to be PC-compatible? I guess we don't actually know. But if you judge by design wins, I cannot remember any. Unfortunately, I don't think that the 286 won any either, so it really doesn't make my point. | > Intel's instruction set architecture was inferior to Motorola's. Not | > so clear about everything else, which does tend to matter. The 386 | > instruction set was as clean as the 68k. | | I have written MMU code for the 386. What a mess. In what way? | I must admit I have never looked at the MMU code for the 68k series | (after all they didn't have it until the 68020 with the optional MMU). | | They are both very much CISC. I think these days ARM and PowerPC are | much nicer to work with. The original ARM MMU had a serious problem. The cache was tagged with virtual addresses. So when you changed the MMU, you had to flush and invalidate each cache entry. Oh, and flushing, as befits a RISC design, took a lot of instructions (one for every cache element?). That made process switching, if it involved an address space switch (as in Linux) quite expensive. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From scruss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Tue Aug 20 03:26:42 2013 From: scruss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Stewart C. Russell) Date: Mon, 19 Aug 2013 23:26:42 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> Message-ID: <5212E1F2.7010505@gmail.com> On 13-08-19 10:48 PM, D. Hugh Redelmeier wrote: > > After the 68000 became viable, when was an 8088 considered for a new > design of a personal computer that was not meant to be PC-compatible? The ill-fated Konix Multisystem used an 8086; I saw it demoed, once, in 1989 before the company folded. It was a lovely machine. Jeff Minter was incredibly keen on it. cheers Stewart -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From opengeometry-FFYn/CNdgSA at public.gmane.org Tue Aug 20 06:20:38 2013 From: opengeometry-FFYn/CNdgSA at public.gmane.org (William Park) Date: Tue, 20 Aug 2013 02:20:38 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> Message-ID: <20130820062038.GA15747@node1.localdomain> On Mon, Aug 19, 2013 at 10:48:29PM -0400, D. Hugh Redelmeier wrote: > Reasonable choices of OS for PCs over the years. > > - DOS > > - From Digital Research: CP/M 86, MP/M (multitasking version), DrDOS > > - UCSD Pascal > > - various genuine UNIXes (quite a few good ones once the 386 came > out). Xenix worked well on 286s (I ran it on an 8086). > > - UNIX clones: Coherent, Whitesmith's Idris, Minix, and others I've forgotten I actually bought Coherent which was one of first roadkill by Linux! > > - BeOS > > - modern UNIXes: *BSD, Linux, OSX, Solaris -- William -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From sciguy-Ja3L+HSX0kI at public.gmane.org Tue Aug 20 12:47:28 2013 From: sciguy-Ja3L+HSX0kI at public.gmane.org (Paul King) Date: Tue, 20 Aug 2013 08:47:28 -0400 Subject: Barely functioning HD, and seeking advice re: how to successfully record in blu-ray Message-ID: <000001ce9da3$6f160ff0$4d422fd0$@net> Hugh said: > (I've reformatted your message because it arrived rather broken up.) I had been using Outlook, and I was compensating for the carriage return problem by inserting my own, and while it looked nice in my window, I guess it may have lost something in translation to other clients. :-( Well, I found the dirty little secret to getting Win 7 BD burning to be more optimal, and that is to run the program as admin. That was not an obvious solution to me, as I went to the trouble of creating a non-admin account for myself, and am in the habit of avoiding running anything as admin, unless I am doing system stuff. Now the success rate is 1 dud in 11, and that was because it was attempting to copy a bad file, which was mis-reported as being zero bytes. I deleted the file, and needed to start again with a new BD. Paul King -------------- next part -------------- An HTML attachment was scrubbed... URL: From clifford_ilkay-biY6FKoJMRdBDgjK7y7TUQ at public.gmane.org Tue Aug 20 15:45:44 2013 From: clifford_ilkay-biY6FKoJMRdBDgjK7y7TUQ at public.gmane.org (CLIFFORD ILKAY) Date: Tue, 20 Aug 2013 11:45:44 -0400 Subject: bargain? 13.3" ultrabook with 1920x1080 for $600 (today only) In-Reply-To: References: Message-ID: <52138F28.1070804@dinamis.com> On 13-08-19 01:19 , D. Hugh Redelmeier wrote: > [snip] > - 4G RAM is a bit low these days and in the future. Probably not > expandable. I overheard a Canada Computers employee who was helping a mom and daughter who had come in to purchase a notebook that even though the 4GB of RAM was soldered on the motherboard and couldn't be upgraded, 4GB was more than enough for Windows 7. He said, "Look, it's only using 1.4GB for Windows so you have plenty more memory." Ouch! -- Regards, Clifford Ilkay -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Tue Aug 20 16:14:41 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Tue, 20 Aug 2013 12:14:41 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> Message-ID: <20130820161441.GH12618@csclub.uwaterloo.ca> On Mon, Aug 19, 2013 at 10:48:29PM -0400, D. Hugh Redelmeier wrote: > The 386 was introduced in 1985. PCs using it came out in 1986. > > OS/2 was first released in December 1987, but probably wasn't useful > (text mode only, ...). Released a year later, 1.1 had a GUI. Many voice mail systems and such ran on it. > So if you wanted to run OS/2, you probably had a 386. It would > happily run as a 286. Most 386s spent their lives emulating 8086s and > perhaps 80286s. > > PC hardware was cutting edge because that was where the competition > was. Well in many ways PC hardware was far from cutting edge. It was just improving quickly in many ways. It took many years for the PC to get anywhere near the hardware capabilities for sound and graphics that the Amiga or even most game consoles at the time had. > PC operating systems were real lagards because there was no > competition. I realize that word is ambiguous. There certainly were > a reasonable number of competing OSes (i.e. competition) but the > actual struggle was so one-sided that it didn't appear to be a > competition. > > Reasonable choices of OS for PCs over the years. > > - DOS > > - From Digital Research: CP/M 86, MP/M (multitasking version), DrDOS > > - UCSD Pascal > > - various genuine UNIXes (quite a few good ones once the 386 came > out). Xenix worked well on 286s (I ran it on an 8086). > > - UNIX clones: Coherent, Whitesmith's Idris, Minix, and others I've forgotten Did SCO or unixware ever qualify as good options? > - BeOS That was never a reasonable choice for anything. Designing a new OS without multiuser or security taken into consideation at all was just amazingly stupid. > - modern UNIXes: *BSD, Linux, OSX, Solaris I have dealt with Solaris x86, and it wasn't pleasant. > After the 68000 became viable, when was an 8088 considered for a new > design of a personal computer that was not meant to be PC-compatible? > I guess we don't actually know. But if you judge by design wins, I > cannot remember any. Unfortunately, I don't think that the 286 won > any either, so it really doesn't make my point. Hmm, the Ontario goverment 'Icon' systems ended up picking the 80186, and they were not intended to be PC compatible. Not an 8086 or 8088, but related. > | I have written MMU code for the 386. What a mess. > > In what way? 16 bits of the address go in one part of the data structure, the next 8 bit somewhere else, and the last 8 bits in yet another place. Very obvious that every time they extended the address range, they threw it at the end and didn't ever think that maybe we will need to do this again so we should reserve room for the future. The x86 is just garbage design pilled on top of garbage design for decades. I haven't dared look where the new 32bit for amd64 ended up. > The original ARM MMU had a serious problem. The cache was tagged with > virtual addresses. So when you changed the MMU, you had to flush and > invalidate each cache entry. Oh, and flushing, as befits a RISC > design, took a lot of instructions (one for every cache element?). > That made process switching, if it involved an address space switch (as > in Linux) quite expensive. Yes the original ARM had some issues, but they seem to have been willing to fix them. The original FPU was horrible too, and they have replaced it with a new, totally incompatible by sane design. Whenever intel decides to thrown away the old and do something better, they end up creating something even more awful (like the Itanium). -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Tue Aug 20 16:32:34 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Tue, 20 Aug 2013 12:32:34 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <20130820161441.GH12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> <20130820161441.GH12618@csclub.uwaterloo.ca> Message-ID: <52139A22.5050509@rogers.com> Lennart Sorensen wrote: > Well in many ways PC hardware was far from cutting edge. It was just > improving quickly in many ways. It took many years for the PC to get > anywhere near the hardware capabilities for sound and graphics that the > Amiga or even most game consoles at the time had. The IBM PC was pretty much built from off the shelf stuff. I was amazed at some of the poor design decisions. One that comes to mind was that interrupts were edge triggered, rather than the commonly used level triggered. This one point made it difficult to share interrupt lines on the bus. Another was putting the BIOS at top of memory, in violation of Intel's guidelines. There were a few other things that caused poor performance even for an 8088. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Tue Aug 20 16:47:33 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Tue, 20 Aug 2013 12:47:33 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <52139A22.5050509-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> <20130820161441.GH12618@csclub.uwaterloo.ca> <52139A22.5050509@rogers.com> Message-ID: <20130820164733.GI12618@csclub.uwaterloo.ca> On Tue, Aug 20, 2013 at 12:32:34PM -0400, James Knott wrote: > The IBM PC was pretty much built from off the shelf stuff. I was amazed > at some of the poor design decisions. One that comes to mind was that > interrupts were edge triggered, rather than the commonly used level > triggered. This one point made it difficult to share interrupt lines on > the bus. Another was putting the BIOS at top of memory, in violation of > Intel's guidelines. There were a few other things that caused poor > performance even for an 8088. Well that is intel's fault actually. The reset start address of x86 is 16 bytes before end of memory. So where else should the BIOS code be located? Given the 8088/8086 had a 20 bit address, that meant the start address was 0xFFFF0 which is the last 16 bytes of the BIOS places at the end of memory. So I don't know what intel's guidelines were, but given the reset PC of the CPU, I don't think there was much choice. A lot of CPU designs start at 0, which makes that a convinient place for the boot ROM. Yet another stupid design decision on intel's part. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Tue Aug 20 18:23:26 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Tue, 20 Aug 2013 14:23:26 -0400 (EDT) Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <20130820161441.GH12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <520D71B1.8040701@gmail.com> <20130816185213.GP7306@csclub.uwaterloo.ca> <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> <20130820161441.GH12618@csclub.uwaterloo.ca> Message-ID: | From: Lennart Sorensen | On Mon, Aug 19, 2013 at 10:48:29PM -0400, D. Hugh Redelmeier wrote: | > The 386 was introduced in 1985. PCs using it came out in 1986. | > | > OS/2 was first released in December 1987, but probably wasn't useful | > (text mode only, ...). Released a year later, 1.1 had a GUI. | | Many voice mail systems and such ran on it. In the era when the 286 was current? Lots of big businesses built infrastructure based on OS/2 since they were promised that it was the future. IT departments fell for it. Banks, ATM networks, Oil companies come to mind. | > PC hardware was cutting edge because that was where the competition | > was. | | Well in many ways PC hardware was far from cutting edge. It was just | improving quickly in many ways. It took many years for the PC to get | anywhere near the hardware capabilities for sound and graphics that the | Amiga or even most game consoles at the time had. Right. I should have qualified the statement somehow. They innovated quickly in things that they thought they could market in the short term. Long-term thinking was reserved for Microsoft, Intel, IBM and various other companies that we've forgotten because it killed them. That's the way monopoly markets work. It took years before the PC market valued multitasking. Remember the horror of TSRs? The PC market was very conservative of interfaces. Remember the A20 fudge? Example: because it was thought that vast amounts of PC software depended on the 8086's wrapping of addresses at 1MiB, chips/systems well into the Pentium era could be set to wrap there. As far as I know, there was very little software that actually broke without this feature. A lot of systems broke due to this feature (i.e. matching A20 handlers with your hardware was non-trivial). | > - UNIX clones: Coherent, Whitesmith's Idris, Minix, and others I've forgotten | | Did SCO or unixware ever qualify as good options? Yes, especially considering MSDOS or OS/2 as the alternatives. They were good, just not to our taste. | > - BeOS | | That was never a reasonable choice for anything. Designing a new OS | without multiuser or security taken into consideation at all was just | amazingly stupid. That one lack doesn't veto it. Remember that the dominant alternative had that limitation too. | > - modern UNIXes: *BSD, Linux, OSX, Solaris | | I have dealt with Solaris x86, and it wasn't pleasant. Why? Lack of familiarity with the SVr5-ness of it? I'm OK with that. BSD has its own flaws. Lack of drivers for your hardware? All alternative OSes have that mountain to climb. | Hmm, the Ontario goverment 'Icon' systems ended up picking the 80186, | and they were not intended to be PC compatible. Not an 8086 or 8088, | but related. Right. That was a bit of a government boondogle. I don't know how the processor was chosen. QNX ran on PC hardware initially, so maybe that was the deciding factory. I think that they used the Watcom C compiler, also targetted at the PC. | > | I have written MMU code for the 386. What a mess. | > | > In what way? | | 16 bits of the address go in one part of the data structure, the | next 8 bit somewhere else, and the last 8 bits in yet another place. | Very obvious that every time they extended the address range, they threw | it at the end and didn't ever think that maybe we will need to do this | again so we should reserve room for the future. The x86 is just garbage | design pilled on top of garbage design for decades. I haven't dared | look where the new 32bit for amd64 ended up. I guess you are referring to the segment descriptors and gate descriptor. Here's an (unreferenced) wikimedia diagram . The parts in italic were added by the 386, and yes, the result isn't contiguous. This is just annoying, not a serious problem. That's kind of how things evolve: not for beauty but for function. | Whenever intel decides to thrown away the old and do something better, | they end up creating something even more awful (like the Itanium). The Itanium was a noble experiment. It's just that (a) they didn't realize it was an experiment, and (b) they poured their resources into the x86 battle, starving the Itanium project, and (c) they took the wind out of the sails (sales?) of RISC processors. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Tue Aug 20 20:11:19 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Tue, 20 Aug 2013 16:11:19 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: References: <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> <20130820161441.GH12618@csclub.uwaterloo.ca> Message-ID: <20130820201119.GJ12618@csclub.uwaterloo.ca> On Tue, Aug 20, 2013 at 02:23:26PM -0400, D. Hugh Redelmeier wrote: > In the era when the 286 was current? > > Lots of big businesses built infrastructure based on OS/2 since they > were promised that it was the future. IT departments fell for it. > Banks, ATM networks, Oil companies come to mind. Yes in the era of the 286 there were some that bet on OS/2 and many of those systems ran for years, long after OS/2 was pretty dead. > Right. I should have qualified the statement somehow. They innovated > quickly in things that they thought they could market in the short > term. > > Long-term thinking was reserved for Microsoft, Intel, IBM and various > other companies that we've forgotten because it killed them. That's > the way monopoly markets work. Well it seems it was companies like 3Dfx and nvidia, creative labs, gravis, and such that really invented neat new stuff for the PC. intel just made it fast, microsoft made it slower, and IBM didn't really do anything after creating the thing in the first place. It took compaq to actually decide to put a 386 in it as a follow up to the 286. IBM was considering changing the architecture. > It took years before the PC market valued multitasking. Remember the > horror of TSRs? Certainly. > The PC market was very conservative of interfaces. Remember the A20 > fudge? Example: because it was thought that vast amounts of PC > software depended on the 8086's wrapping of addresses at 1MiB, > chips/systems well into the Pentium era could be set to wrap there. > As far as I know, there was very little software that actually broke > without this feature. A lot of systems broke due to this feature > (i.e. matching A20 handlers with your hardware was non-trivial). I remember the A20 wrapping was managed through a pin on the keyboard controller for some silly reason. > That one lack doesn't veto it. Remember that the dominant alternative > had that limitation too. Windows NT was already vastly more capable in that regard, as were all the unix systems. > Why? I remember it didn't even have a termcap for it's own console type. Solaris on sparc worked great. Solaris on x86 not so much. ssh to a linux box, and the linux box knew how to deal with a solaris x86 console, but solaris itself had no clue. It was embarasing how neglected the x86 version was by Sun. They clearly didn't care about it. > Lack of familiarity with the SVr5-ness of it? I'm OK with that. BSD > has its own flaws. I prefer to avoid BSD's concept of user space. > Lack of drivers for your hardware? All alternative OSes have that > mountain to climb. Actually it seemed to manage OK at driver support at the time. > Right. That was a bit of a government boondogle. I don't know how > the processor was chosen. QNX ran on PC hardware initially, so maybe > that was the deciding factory. I think that they used the Watcom C > compiler, also targetted at the PC. Actually QNX may very well have been the reason. > I guess you are referring to the segment descriptors and gate > descriptor. Here's an (unreferenced) wikimedia diagram > . The > parts in italic were added by the 386, and yes, the result isn't > contiguous. This is just annoying, not a serious problem. That's > kind of how things evolve: not for beauty but for function. Many designs try to plan ahead so they don't end up with such a mess. One would think that after extending the architecture enough times they could start to plan ahead, but it seems intel never does. > The Itanium was a noble experiment. It's just that (a) they didn't > realize it was an experiment, and (b) they poured their resources into > the x86 battle, starving the Itanium project, and (c) they took the > wind out of the sails (sales?) of RISC processors. It was the second (or maybe third) time intel tried to do VLIW architecture, and again it failed because it can't be done. It seems that intel kept thinking compiler developers would eventually solve the compile time scheduling issue. I believe I read somewhere that is has now been proven to be unsolvable at compile time. Maybe now intel won't try it again. VLIW is best left for DSPs where you have predictable workflows. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From richard-gNTHUr35LhcAvxtiuMwx3w at public.gmane.org Tue Aug 20 21:02:06 2013 From: richard-gNTHUr35LhcAvxtiuMwx3w at public.gmane.org (Richard Weait) Date: Tue, 20 Aug 2013 17:02:06 -0400 Subject: OT: seeking table saw or circular saw to use. Message-ID: Yeah. So, that's way OT, but it's for wood that will eventually support a computer running Linux. Really. Looking to rip two 2m oak boards. At an angle. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Tue Aug 20 21:49:12 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Tue, 20 Aug 2013 17:49:12 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <20130820164733.GI12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> <20130820161441.GH12618@csclub.uwaterloo.ca> <52139A22.5050509@rogers.com> <20130820164733.GI12618@csclub.uwaterloo.ca> Message-ID: <5213E458.30507@rogers.com> Lennart Sorensen wrote: > Well that is intel's fault actually. The reset start address of x86 > is 16 bytes before end of memory. So where else should the BIOS code > be located? Given the 8088/8086 had a 20 bit address, that meant the > start address was 0xFFFF0 which is the last 16 bytes of the BIOS places > at the end of memory. So I don't know what intel's guidelines were, > but given the reset PC of the CPU, I don't think there was much choice. Well, I just happen to have handy "The 8086 Family Users Manual" published by Intel in 1979. On page 2-14: "Dedicated and Reserved Memory Locations Two areas in extreme low and high memory are dedicatied to specific processor functions or reserved by Intel Corporation for use by Intel hardware and software products. As shown in figure 2-21, the location are: 0H through 7FH (128 bytes) and FFFF0H through FFFFFH (16 bytes). These areas are used for interrupt and system reset processing. 8086 and 8088 application systems should not use these areas for any other purpose. Doing so may make these system incompatible with future Intel products." This would tend to rule out IBM putting stuff at the top 16 bytes. However, I have seen systems that use "ghost" ROM, where ROM memory from elsewhere is made to temporarily appear at a specific location in the memory space. The Data General line did that, IIRC. It's been too many years since I looked at this sort of thing in any detail to remember. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Tue Aug 20 22:31:11 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Tue, 20 Aug 2013 18:31:11 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <5213E458.30507-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> <20130820161441.GH12618@csclub.uwaterloo.ca> <52139A22.5050509@rogers.com> <20130820164733.GI12618@csclub.uwaterloo.ca> <5213E458.30507@rogers.com> Message-ID: <5213EE2F.3020506@rogers.com> James Knott wrote: > It's been too many years since I looked at this sort of thing in any > detail to remember. One thing that comes to mind was memory expansion. By putting ROM there, IBM blocked Intel's plans for going beyond 1 MB with the 8088/8086. If you'd asked me back in the '80s, I could have told you what the reason was. Back then, I was a computer tech working on mini-computers and very interested in CPU and system architecture, even reading about CPUs and systems that I didn't work with. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From phiscock-g851W1bGYuGnS0EtXVNi6w at public.gmane.org Tue Aug 20 22:32:13 2013 From: phiscock-g851W1bGYuGnS0EtXVNi6w at public.gmane.org (phiscock-g851W1bGYuGnS0EtXVNi6w at public.gmane.org) Date: Tue, 20 Aug 2013 18:32:13 -0400 Subject: OT: seeking table saw or circular saw to use. In-Reply-To: References: Message-ID: <11b585a94e9dd4d22b12fd58505b3663.squirrel@webmail.ee.ryerson.ca> I'm in the middle of a renovation with a table saw set up in my living room, so if you want to bring them around here, I'm game. 416-465-3007 Peter > Yeah. So, that's way OT, but it's for wood that will eventually > support a computer running Linux. Really. > > Looking to rip two 2m oak boards. At an angle. > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -- Peter Hiscocks Syscomp Electronic Design Limited, Toronto http://www.syscompdesign.com USB Oscilloscope and Waveform Generator 647-839-0325 -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Tue Aug 20 22:56:55 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Tue, 20 Aug 2013 18:56:55 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <5213E458.30507-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> <20130820161441.GH12618@csclub.uwaterloo.ca> <52139A22.5050509@rogers.com> <20130820164733.GI12618@csclub.uwaterloo.ca> <5213E458.30507@rogers.com> Message-ID: <5213F437.1040409@rogers.com> James Knott wrote: > However, I have seen systems that use "ghost" ROM Sorry, I believe the term used was "phantom" memory. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From waltdnes-SLHPyeZ9y/tg9hUCZPvPmw at public.gmane.org Wed Aug 21 00:49:06 2013 From: waltdnes-SLHPyeZ9y/tg9hUCZPvPmw at public.gmane.org (Walter Dnes) Date: Tue, 20 Aug 2013 20:49:06 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: References: <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> <20130820161441.GH12618@csclub.uwaterloo.ca> Message-ID: <20130821004906.GC18970@waltdnes.org> On Tue, Aug 20, 2013 at 02:23:26PM -0400, D. Hugh Redelmeier wrote > The Itanium was a noble experiment. It's just that (a) they didn't > realize it was an experiment, and (b) they poured their resources into > the x86 battle, starving the Itanium project, and (c) they took the > wind out of the sails (sales?) of RISC processors. An old internet post with a cynical take on the "Itanic disaster". > Is Microsoft responsible for Intel's Itanic disaster? > Authored by: Anonymous on Tuesday, February 21 2006 @ 04:12 PM EST > There was no Itanic disaster. > Remember, when Intel started the Itanium bluff, they hand zero > presence in 64-bit computing and very limited presence in high-end > computing. Leading 64-bit players were MIPS/SGI, Alpha/Dec, > PA-RISC/HP, and yes, IBM and Sparc. > > In fear of Itanium, SGI spun-off MIPS and became a Wintel reseller. > Compaq feared Itanium would quickly kill DEC's Alpha and gave it to > Intel when they bought DEC. HP redirected their hardware resources > away from PA-RISC to their intel/itanium partnership. > > Without laying out a single transistor, Itanium completely destroyed > 3 of the 5 64-bit competitors; and Intel went from being a PC desktop > brand to a wall-street-recognised leader in high-end computing. > > Never was there a more successful bluff in business. I don't see > how people can consider that a failure. -- Walter Dnes I don't run "desktop environments"; I run useful applications -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From waltdnes-SLHPyeZ9y/tg9hUCZPvPmw at public.gmane.org Wed Aug 21 01:02:10 2013 From: waltdnes-SLHPyeZ9y/tg9hUCZPvPmw at public.gmane.org (Walter Dnes) Date: Tue, 20 Aug 2013 21:02:10 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <20130820164733.GI12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> <20130820161441.GH12618@csclub.uwaterloo.ca> <52139A22.5050509@rogers.com> <20130820164733.GI12618@csclub.uwaterloo.ca> Message-ID: <20130821010210.GD18970@waltdnes.org> On Tue, Aug 20, 2013 at 12:47:33PM -0400, Lennart Sorensen wrote > Well that is intel's fault actually. The reset start address of x86 > is 16 bytes before end of memory. So where else should the BIOS code > be located? Given the 8088/8086 had a 20 bit address, that meant the > start address was 0xFFFF0 which is the last 16 bytes of the BIOS places > at the end of memory. So I don't know what intel's guidelines were, > but given the reset PC of the CPU, I don't think there was much choice. > > A lot of CPU designs start at 0, which makes that a convinient place > for the boot ROM. Yet another stupid design decision on intel's part. What could have been... Intel's 20-bit addressing scheme consisted of a real address that was defined by 2 16-bit registers, i.e... ( 16 * base_reg ) + offset_reg 16 = 2^4, so that only gave 1 megabyte of address space in "real mode" for DOS (20 bits). Now imagine if they had made it ( 256 * base_reg ) + offset_reg which would give 16 megabytes of real mode for DOS (24 bits). Even better would be... ( 4096 * base_reg ) + offset_reg which would give 256 megabytes of real mode for DOS (28 bits). OS/2, EMS, XMS, HIMEM, etc would never have seen the light of day. -- Walter Dnes I don't run "desktop environments"; I run useful applications -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Wed Aug 21 01:08:06 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Tue, 20 Aug 2013 21:08:06 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <20130821010210.GD18970-SLHPyeZ9y/tg9hUCZPvPmw@public.gmane.org> References: <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> <20130820161441.GH12618@csclub.uwaterloo.ca> <52139A22.5050509@rogers.com> <20130820164733.GI12618@csclub.uwaterloo.ca> <20130821010210.GD18970@waltdnes.org> Message-ID: <521412F6.4010800@rogers.com> Walter Dnes wrote: > which would give 256 megabytes of real mode for DOS (28 bits). OS/2, > EMS, XMS, HIMEM, etc would never have seen the light of day. There were more problems with DOS than just memory space. It was single tasking, among other issue, such as poor I/O support. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From erik.levinson-IaPBhvjdSnNWk0Htik3J/w at public.gmane.org Wed Aug 21 01:43:00 2013 From: erik.levinson-IaPBhvjdSnNWk0Htik3J/w at public.gmane.org (Erik Levinson) Date: Tue, 20 Aug 2013 21:43:00 -0400 (EDT) Subject: Dell PowerEdge servers for sale - $50 each Message-ID: <1377049380.039716683@apps.rackspace.com> All, As before, we're getting rid of some more of our old Dell PowerEdge servers ($50 each). This will be the second last batch, and the last one will be about six PE2950s probably in January. 1. 1U PowerEdge 1950 two dual-core Xeon 5160s 3.0Ghz (64-bit, VT-capable), 16GB RAM, dual power, rails, PERC 5/i RAID controller, cd drive, no hard drives 2. 1U PowerEdge 1950 two dual-core 3.0Ghz, has a bad RAM slot, dual power, rails, PERC 5/i RAID controller, no hard drives. cd drive. 3. 1U PowerEdge 1850, 4GB of RAM, 64-bit two dual-core Xeon 3.4Ghz CPUs, PERC4 RAID controller, dual power supplies, rails, cd drive, no hard drives 4. 1U PowerEdge 1850, 4GB of RAM, 64-bit two dual-core Xeon 3.4Ghz CPUs, PERC4 RAID controller, dual power supplies, rails, cd drive, no hard drives 5. 2U PowerEdge 2850, 4GB of RAM, 64-bit two dual-core Xeon 3.2Ghz CPUs, PERC4 RAID controller, dual power supplies, rails, cd drive, no hard drives 6. Random sets of rails for PowerEdge 2850s/1850s - free and will be included with the above even if you don't want them :) All pulled from service at the colo. All are being sold as-is with no warranty. Pick up from our office at King & Dufferin at a pre-arranged time when I'm present. Thanks -- Erik Levinson CTO, Uberflip 416-900-3830 1183 King Street West, Suite 100 Toronto ON M6K 3C5 www.uberflip.com -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From talexb-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Wed Aug 21 02:19:43 2013 From: talexb-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Alex Beamish) Date: Tue, 20 Aug 2013 22:19:43 -0400 Subject: Dell PowerEdge servers for sale - $50 each In-Reply-To: <1377049380.039716683-0ZYIasU8DW2IAIbY1eLdq9BPR1lH4CV8@public.gmane.org> References: <1377049380.039716683@apps.rackspace.com> Message-ID: Hi Erik, I'd like the first unit if it's still available. Alex Beamish On Tue, Aug 20, 2013 at 9:43 PM, Erik Levinson wrote: > All, > > As before, we're getting rid of some more of our old Dell PowerEdge > servers ($50 each). This will be the second last batch, and the last one > will be about six PE2950s probably in January. > > 1. 1U PowerEdge 1950 two dual-core Xeon 5160s 3.0Ghz (64-bit, VT-capable), > 16GB RAM, dual power, rails, PERC 5/i RAID controller, cd drive, no hard > drives > > 2. 1U PowerEdge 1950 two dual-core 3.0Ghz, has a bad RAM slot, dual power, > rails, PERC 5/i RAID controller, no hard drives. cd drive. > > 3. 1U PowerEdge 1850, 4GB of RAM, 64-bit two dual-core Xeon 3.4Ghz CPUs, > PERC4 RAID controller, dual power supplies, rails, cd drive, no hard drives > > 4. 1U PowerEdge 1850, 4GB of RAM, 64-bit two dual-core Xeon 3.4Ghz CPUs, > PERC4 RAID controller, dual power supplies, rails, cd drive, no hard drives > > 5. 2U PowerEdge 2850, 4GB of RAM, 64-bit two dual-core Xeon 3.2Ghz CPUs, > PERC4 RAID controller, dual power supplies, rails, cd drive, no hard drives > > 6. Random sets of rails for PowerEdge 2850s/1850s - free and will be > included with the above even if you don't want them :) > > > All pulled from service at the colo. All are being sold as-is with no > warranty. Pick up from our office at King & Dufferin at a pre-arranged time > when I'm present. > > Thanks > > -- > Erik Levinson > CTO, Uberflip > 416-900-3830 > 1183 King Street West, Suite 100 > Toronto ON M6K 3C5 > www.uberflip.com > > > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -- Alex Beamish Toronto, Ontario aka talexb -------------- next part -------------- An HTML attachment was scrubbed... URL: From richard-gNTHUr35LhcAvxtiuMwx3w at public.gmane.org Wed Aug 21 13:40:26 2013 From: richard-gNTHUr35LhcAvxtiuMwx3w at public.gmane.org (Richard Weait) Date: Wed, 21 Aug 2013 09:40:26 -0400 Subject: OT: seeking table saw or circular saw to use. In-Reply-To: <11b585a94e9dd4d22b12fd58505b3663.squirrel-2RFepEojUI2DznVbVsZi4adLQS1dU2Lr@public.gmane.org> References: <11b585a94e9dd4d22b12fd58505b3663.squirrel@webmail.ee.ryerson.ca> Message-ID: Thank you! -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Wed Aug 21 14:13:11 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Wed, 21 Aug 2013 10:13:11 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <20130821004906.GC18970-SLHPyeZ9y/tg9hUCZPvPmw@public.gmane.org> References: <20130816205858.GA12618@csclub.uwaterloo.ca> <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> <20130820161441.GH12618@csclub.uwaterloo.ca> <20130821004906.GC18970@waltdnes.org> Message-ID: <20130821141311.GK12618@csclub.uwaterloo.ca> On Tue, Aug 20, 2013 at 08:49:06PM -0400, Walter Dnes wrote: > On Tue, Aug 20, 2013 at 02:23:26PM -0400, D. Hugh Redelmeier wrote > > > The Itanium was a noble experiment. It's just that (a) they didn't > > realize it was an experiment, and (b) they poured their resources into > > the x86 battle, starving the Itanium project, and (c) they took the > > wind out of the sails (sales?) of RISC processors. > > An old internet post with a cynical take on the "Itanic disaster". > > > Is Microsoft responsible for Intel's Itanic disaster? > > Authored by: Anonymous on Tuesday, February 21 2006 @ 04:12 PM EST > > There was no Itanic disaster. > > > Remember, when Intel started the Itanium bluff, they hand zero > > presence in 64-bit computing and very limited presence in high-end > > computing. Leading 64-bit players were MIPS/SGI, Alpha/Dec, > > PA-RISC/HP, and yes, IBM and Sparc. > > > > In fear of Itanium, SGI spun-off MIPS and became a Wintel reseller. > > Compaq feared Itanium would quickly kill DEC's Alpha and gave it to > > Intel when they bought DEC. HP redirected their hardware resources > > away from PA-RISC to their intel/itanium partnership. > > > > Without laying out a single transistor, Itanium completely destroyed > > 3 of the 5 64-bit competitors; and Intel went from being a PC desktop > > brand to a wall-street-recognised leader in high-end computing. > > > > Never was there a more successful bluff in business. I don't see > > how people can consider that a failure. As a CPU design it is a failure. As a business decision, they seem to have pulled it of very well. It pretty much killed SGI, and as for compaq and HP (now one company), they aren't doing well in that side of the business either, although HP is the only company that has anything to do with Itanium anymore. Their customers don't seem very happy either given there seems to still be features of True64 that haven't made it to HP-UX for the Itanium that they want and I think the Alpha machines are just about to stop being available to buy. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Wed Aug 21 14:17:14 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Wed, 21 Aug 2013 10:17:14 -0400 Subject: C integral types [was Re: Semi-OT: Why Kids Can't use Computers] (fwd) In-Reply-To: <5213E458.30507-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <520E95AE.6010201@rogers.com> <20130816220638.GC12618@csclub.uwaterloo.ca> <20130817002335.GA24896@node1.localdomain> <20130819205618.GG12618@csclub.uwaterloo.ca> <20130820161441.GH12618@csclub.uwaterloo.ca> <52139A22.5050509@rogers.com> <20130820164733.GI12618@csclub.uwaterloo.ca> <5213E458.30507@rogers.com> Message-ID: <20130821141714.GL12618@csclub.uwaterloo.ca> On Tue, Aug 20, 2013 at 05:49:12PM -0400, James Knott wrote: > Well, I just happen to have handy "The 8086 Family Users Manual" > published by Intel in 1979. > > On page 2-14: > > "Dedicated and Reserved Memory Locations > > Two areas in extreme low and high memory are dedicatied to specific > processor functions or reserved by Intel Corporation for use by Intel > hardware and software products. As shown in figure 2-21, the location > are: 0H through 7FH (128 bytes) and FFFF0H through FFFFFH (16 bytes). > These areas are used for interrupt and system reset processing. 8086 > and 8088 application systems should not use these areas for any other > purpose. Doing so may make these system incompatible with future Intel > products." > > This would tend to rule out IBM putting stuff at the top 16 bytes. IBM put the startup code there. What else is system reset processing? If there is nothing at that address, the system won't do anything. And yes the low end has all the IO ports. It doesn't say "don't put stuff here". It says it has special purpose. So you can't put something random at those addresses and expect it to work, but you can put stuff that does what is expected there, and that is exactly what IBM did. They put IO decides in the IO port range, and they put the ROM in the system reset execution range. Can you find ANY system ever made with an 8086/8088 that does NOT have ROM at FFFF0-FFFFF to handle system startup? > However, I have seen systems that use "ghost" ROM, where ROM memory from > elsewhere is made to temporarily appear at a specific location in the > memory space. The Data General line did that, IIRC. Many systems do. Chip selecting ROM to address 0 at reset is common, and then the system remaps it to somewhere better later when it has decided what should go where. > It's been too many years since I looked at this sort of thing in any > detail to remember. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From moptop99-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Wed Aug 21 21:40:03 2013 From: moptop99-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Matt Price) Date: Wed, 21 Aug 2013 17:40:03 -0400 Subject: laptop advice time... Message-ID: Hi, I'm looking for a replacement for my lenovo t410 (got wet!). I am considering getting one of the newer editions of the same (t430, t430s, t430u...), but I wanted to check in and see what machines y'all recommend. I'm looking for: - a really nice keyboard -- I spend most of my day typing. Lenovo used to have the nicest eyboards around but I thin that has really changed. - perfect Linux support for graphics, touchpads, etc -- I have a busy time coming up and I don't want to spend time futzing with this machine - half-decent speakers would be nice too, as I watch movies & stff on my laptop. That's really about all I need. I really welcome your help! Thanks, Matt -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Wed Aug 21 22:24:07 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Wed, 21 Aug 2013 18:24:07 -0400 Subject: laptop advice time... In-Reply-To: References: Message-ID: <20130821222407.GM12618@csclub.uwaterloo.ca> On Wed, Aug 21, 2013 at 05:40:03PM -0400, Matt Price wrote: > I'm looking for a replacement for my lenovo t410 (got wet!). I am > considering getting one of the newer editions of the same (t430, > t430s, t430u...), but I wanted to check in and see what machines y'all > recommend. I'm looking for: > > - a really nice keyboard -- I spend most of my day typing. Lenovo > used to have the nicest eyboards around but I thin that has really > changed. Not that I can tell. Seems good. > - perfect Linux support for graphics, touchpads, etc -- I have a busy > time coming up and I don't want to spend time futzing with this > machine > - half-decent speakers would be nice too, as I watch movies & stff on my laptop. I have a W530, and I am very happy with it so far. The keyboard is really nice on it (and backlit in my case). As far as I know the W530 is very similar to a T530, except it has a different graphics chip line, and twice as many ram slots. I believe the T430 is similar to the T530 other than screen size and physical dimensions. I expect the linux compatibility to be quite good, but I must admit I don't actually know yet. I got it in November and I still haven't had time to install Linux on it. Note that I did have a daughter born the same week i got the W530, so i have a valid excuse, and Windows 7 with firefox is a perfectly good web browser, and you can play games on windows too. The desktop machine is where Linux is always running. :) I did just upgrade the disk to a 1TB so make room to install linux, so I will probably do it soon. Then I get to play with bumblebee to see how the intel/nvidia graphics switching works. The speakers on the W530 are vastly better than other thinkpads I have seen or used before. They are pretty decent (although nothing like the ones in the ideapad Y410 my wife has, which are made by JBL). -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From grazer-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Wed Aug 21 22:57:45 2013 From: grazer-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Jason Shaw) Date: Wed, 21 Aug 2013 18:57:45 -0400 Subject: laptop advice time... In-Reply-To: <20130821222407.GM12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130821222407.GM12618@csclub.uwaterloo.ca> Message-ID: I have the Lenovo X1 Carbon (I bought it largely due to a case of the "ooh shiny"s) and I run gentoo on it. I've had it for 8 months or so and it's been great. It has 1900x1200 resolution on a 14" screen, a large trackpad (which can be a bit sensitive at times but I only use it for two finger scrolling of long articles), the keyboard is good with a solid feel and good travel despite it's thinness, and most importantly good linux support. The downsides (and they are huge for some) are all related to it not being upgradeable; the RAM is soldered and the SSD is proprietary. Those aside, it's been a wonderful machine for my usage (browsing, virtualbox, sshing into remote machines, scripting, etc). On Wed, Aug 21, 2013 at 6:24 PM, Lennart Sorensen wrote: > On Wed, Aug 21, 2013 at 05:40:03PM -0400, Matt Price wrote: >> I'm looking for a replacement for my lenovo t410 (got wet!). I am >> considering getting one of the newer editions of the same (t430, >> t430s, t430u...), but I wanted to check in and see what machines y'all >> recommend. I'm looking for: >> >> - a really nice keyboard -- I spend most of my day typing. Lenovo >> used to have the nicest eyboards around but I thin that has really >> changed. > > Not that I can tell. Seems good. > >> - perfect Linux support for graphics, touchpads, etc -- I have a busy >> time coming up and I don't want to spend time futzing with this >> machine >> - half-decent speakers would be nice too, as I watch movies & stff on my laptop. > > I have a W530, and I am very happy with it so far. The keyboard is really > nice on it (and backlit in my case). As far as I know the W530 is > very similar to a T530, except it has a different graphics chip line, > and twice as many ram slots. > > I believe the T430 is similar to the T530 other than screen size and > physical dimensions. > > I expect the linux compatibility to be quite good, but I must admit > I don't actually know yet. I got it in November and I still haven't > had time to install Linux on it. Note that I did have a daughter born > the same week i got the W530, so i have a valid excuse, and Windows 7 > with firefox is a perfectly good web browser, and you can play games on > windows too. The desktop machine is where Linux is always running. :) > > I did just upgrade the disk to a 1TB so make room to install linux, > so I will probably do it soon. Then I get to play with bumblebee to > see how the intel/nvidia graphics switching works. > > The speakers on the W530 are vastly better than other thinkpads I have > seen or used before. They are pretty decent (although nothing like the > ones in the ideapad Y410 my wife has, which are made by JBL). > > -- > Len Sorensen > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hgibson-MwcKTmeKVNQ at public.gmane.org Wed Aug 21 23:40:39 2013 From: hgibson-MwcKTmeKVNQ at public.gmane.org (Howard Gibson) Date: Wed, 21 Aug 2013 19:40:39 -0400 Subject: laptop advice time... In-Reply-To: References: Message-ID: <20130821194039.21abcd73259588080827b59d@eol.ca> On Wed, 21 Aug 2013 17:40:03 -0400 Matt Price wrote: > Hi, > > I'm looking for a replacement for my lenovo t410 (got wet!). I am > considering getting one of the newer editions of the same (t430, > t430s, t430u...), but I wanted to check in and see what machines y'all > recommend. I'm looking for: Matt, My Lenovo T400 has a "spill resistant" keyboard. I have no desire to test this. I spilled beer on one of my old laptops. I thought it was toast, but it worked fine a day later after it dried off. I am very happy with my Lenovo. -- Howard Gibson hgibson-MwcKTmeKVNQ at public.gmane.org howard.gibson-PadmjKOQAFnQT0dZR+AlfA at public.gmane.org jhowardgibson-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org http://home.eol.ca/~hgibson -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From peter.king-H217xnMUJC0sA/PxXw9srA at public.gmane.org Thu Aug 22 03:03:10 2013 From: peter.king-H217xnMUJC0sA/PxXw9srA at public.gmane.org (Peter King) Date: Wed, 21 Aug 2013 23:03:10 -0400 Subject: laptop advice time... In-Reply-To: References: Message-ID: <20130822030310.GB27852@amber> I have a Lenovo W510, which is a delightful machine and everything Just Works on it (except perhaps the modem which I've never had occasion to try out). The keyboard is the old-style IBM keyboard, which is terrific, not the recent "chiclet" style that seems to have become the Lenovo norm. I would not buy that keyboard, so you need to be very careful about just what is available and what you're willing to put up with. Otherwise, I run gentoo on the W510, and as noted it all runs without any sort of hiccup -- it just works. Lots of RAM, quad-core with multithreading gives you eight virtual processors, good screen resolution... If you can find one with the right keyboard, buy it; you won't be disappointed. -- Peter King peter.king-H217xnMUJC0sA/PxXw9srA at public.gmane.org Department of Philosophy 170 St. George Street #521 The University of Toronto (416)-978-4951 ofc Toronto, ON M5R 2M8 CANADA http://individual.utoronto.ca/pking/ ========================================================================= GPG keyID 0x7587EC42 (2B14 A355 46BC 2A16 D0BC 36F5 1FE6 D32A 7587 EC42) gpg --keyserver pgp.mit.edu --recv-keys 7587EC42 -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 198 bytes Desc: Digital signature URL: From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Thu Aug 22 04:54:57 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Thu, 22 Aug 2013 00:54:57 -0400 (EDT) Subject: laptop advice time... In-Reply-To: References: Message-ID: | From: Matt Price | I'm looking for a replacement for my lenovo t410 (got wet!). I am | considering getting one of the newer editions of the same (t430, | t430s, t430u...), but I wanted to check in and see what machines y'all | recommend. I'm looking for: Those are good. But heavy and expensive. Note that there are sometimes astonishingly good deals on thinkpads (but not when you want them). Over the years I've purchased three such bargains. There are EPP codes floating around to help. I find the new ultrabook format attractive but have never actually used one: - svelte - light (but not as light as they look) - long battery life (some models) - not upgradeable (battery, ram, disk are often not replaceable) - chicklet keyboard | - a really nice keyboard -- I spend most of my day typing. Lenovo | used to have the nicest eyboards around but I thin that has really | changed. The chiclet keyboards are apparently cool. You've got to decide it you love them, hate them, or don't care. | - perfect Linux support for graphics, touchpads, etc -- I have a busy | time coming up and I don't want to spend time futzing with this | machine Intel graphics is good enough for me. nvidia graphics (discrete) is now combined with intel graphic (on chip) on many ThinkPads. The combinatino is awkward. For low power, you use intel; for heavy-duty graphics you turn on and switch to the nvidia. Supposedly this is automatic, but I don't think that it works in Linux yet. I use a BIOS setting to switch (requires a reboot -- not convenient). Lennart referred to Bumblebee which is supposed to do it better. | - half-decent speakers would be nice too, as I watch movies & stff on my laptop. Do you need a DVD drive? That knocks out ultrabooks. | That's really about all I need. I really welcome your help! Thanks, My desire is for a lot of pixels. That seems to seriously increase the price of a notebook. Lenovo usually has decent screen options for ThinkPads (not cheap). There are a million inexpensive notebooks that might be good enough. Haswell chips (the latest generation of Intel processors) seem to increase battery life significantly. But that may be mostly while they are idle (not sure). SSDs have their place. They make for fast boots. Depends on your capacity needs. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Thu Aug 22 05:07:28 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Thu, 22 Aug 2013 01:07:28 -0400 (EDT) Subject: laptop advice time... In-Reply-To: <20130821222407.GM12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130821222407.GM12618@csclub.uwaterloo.ca> Message-ID: | From: Lennart Sorensen | I have a W530, and I am very happy with it so far. The keyboard is really | nice on it (and backlit in my case). As far as I know the W530 is | very similar to a T530, except it has a different graphics chip line, | and twice as many ram slots. | | I believe the T430 is similar to the T530 other than screen size and | physical dimensions. | | I expect the linux compatibility to be quite good, but I must admit | I don't actually know yet. I got it in November and I still haven't | had time to install Linux on it. Yikes! W530 seems fine under Linux (Fedora). We haven't exploited the nvidia chip. Ditto for T520 (Ubuntu 12.04 LTS) (some undiagnosed freezes, mostly while watching videos). | Note that I did have a daughter born | the same week i got the W530, so i have a valid excuse, Congratulations! | I did just upgrade the disk to a 1TB so make room to install linux, | so I will probably do it soon. Consider adding an mSATA SSD. The w530 and T520 have a slot for that (unless you are using the slot for a wireless (cell) card). | Then I get to play with bumblebee to | see how the intel/nvidia graphics switching works. Tell us how that works out. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From andrew-2KHxOkysSnqmy7d5DmSz6TlRY1/6cnIP at public.gmane.org Thu Aug 22 00:32:11 2013 From: andrew-2KHxOkysSnqmy7d5DmSz6TlRY1/6cnIP at public.gmane.org (Andrew Cowie) Date: Thu, 22 Aug 2013 10:32:11 +1000 Subject: laptop advice time... In-Reply-To: References: Message-ID: <1377131531.6410.2.camel@turminder-xuss.roaming.operationaldynamics.com> On Wed, 2013-08-21 at 17:40 -0400, Matt Price wrote: > I'm looking for a replacement for my lenovo t410 (got wet!). I am > considering getting one of the newer editions of the same (t430, > t430s, t430u...), Work is about to give me a new T430, so I'll let you know in a few days how it goes... AfC Sydney -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From gilesorr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 22 11:56:12 2013 From: gilesorr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Giles Orr) Date: Thu, 22 Aug 2013 07:56:12 -0400 Subject: 4K TVs anyone? Message-ID: There was some talk of these earlier. Tiger Direct is selling the 39" and 50" Seiki 4K TVs for $700 and $1050 respectively: http://www.redflagdeals.com/deal/televisions/tigerdirectca-seiki-39-class-led-4k-ultra-hdtv-700-seiki-50-class-4k-led-hdtv-1050-cash-back/ I don't have a video card that could drive the damn thing, so I'm going to pass. Too bad. -- Giles http://www.gilesorr.com/ gilesorr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org -------------- next part -------------- An HTML attachment was scrubbed... URL: From scruss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 22 12:28:25 2013 From: scruss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Stewart Russell) Date: Thu, 22 Aug 2013 08:28:25 -0400 Subject: laptop advice time... In-Reply-To: References: Message-ID: The keyboard - full, with numeric pad - on my Samsung Series 7 is very nice. Great sound and the screen is lovely. Only two things you might not like: * battery is only replaceable through major disassembly; * the thing is a power hog. Typically draws 40 W, 70+ if it's working hard. I could spend a lot more time futzing with the power settings to make it scale - without the Samsung (open source) drivers it runs the fan all the time. Cheers Stewart -------------- next part -------------- An HTML attachment was scrubbed... URL: From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Thu Aug 22 13:35:35 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Thu, 22 Aug 2013 09:35:35 -0400 Subject: laptop advice time... In-Reply-To: <20130822030310.GB27852@amber> References: <20130822030310.GB27852@amber> Message-ID: <20130822133535.GN12618@csclub.uwaterloo.ca> On Wed, Aug 21, 2013 at 11:03:10PM -0400, Peter King wrote: > I have a Lenovo W510, which is a delightful machine and everything Just > Works on it (except perhaps the modem which I've never had occasion to > try out). The keyboard is the old-style IBM keyboard, which is terrific, > not the recent "chiclet" style that seems to have become the Lenovo norm. > I would not buy that keyboard, so you need to be very careful about just > what is available and what you're willing to put up with. I am pretty sure the keyboard on my W530 is chiclet style, but it is a very nice keyboard to work with. > Otherwise, I run gentoo on the W510, and as noted it all runs without any > sort of hiccup -- it just works. Lots of RAM, quad-core with multithreading > gives you eight virtual processors, good screen resolution... If you can > find one with the right keyboard, buy it; you won't be disappointed. How much ram can you put in the W510? I currently have 24GB in my W530 out of the maximum 32GB. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Thu Aug 22 13:39:50 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Thu, 22 Aug 2013 09:39:50 -0400 Subject: laptop advice time... In-Reply-To: References: Message-ID: <20130822133950.GO12618@csclub.uwaterloo.ca> On Thu, Aug 22, 2013 at 12:54:57AM -0400, D. Hugh Redelmeier wrote: > Those are good. But heavy and expensive. > > Note that there are sometimes astonishingly good deals on thinkpads > (but not when you want them). Over the years I've purchased three > such bargains. There are EPP codes floating around to help. I got mine during black friday last november. Given that was about 2 or 3 weeks after the screen on my old laptop failed and I managed to make it worse when trying to fix it, the timing wasn't too bad then. > I find the new ultrabook format attractive but have never actually > used one: > > - svelte > - light (but not as light as they look) > - long battery life (some models) > - not upgradeable (battery, ram, disk are often not replaceable) > - chicklet keyboard > > | - a really nice keyboard -- I spend most of my day typing. Lenovo > | used to have the nicest eyboards around but I thin that has really > | changed. > > The chiclet keyboards are apparently cool. You've got to decide it > you love them, hate them, or don't care. Also the chiclet keyboard on an eeepc and a thinkpad is not the same thing. > Intel graphics is good enough for me. > > nvidia graphics (discrete) is now combined with intel graphic (on > chip) on many ThinkPads. The combinatino is awkward. For low power, > you use intel; for heavy-duty graphics you turn on and switch to the > nvidia. Supposedly this is automatic, but I don't think that it works > in Linux yet. I use a BIOS setting to switch (requires a reboot -- > not convenient). Lennart referred to Bumblebee which is supposed to > do it better. > > | - half-decent speakers would be nice too, as I watch movies & stff on my laptop. > > Do you need a DVD drive? That knocks out ultrabooks. > > | That's really about all I need. I really welcome your help! Thanks, > > My desire is for a lot of pixels. That seems to seriously increase > the price of a notebook. Lenovo usually has decent screen options for > ThinkPads (not cheap). > > There are a million inexpensive notebooks that might be good enough. > > Haswell chips (the latest generation of Intel processors) seem to > increase battery life significantly. But that may be mostly while > they are idle (not sure). > > SSDs have their place. They make for fast boots. Depends on your > capacity needs. I have noticed that the build and design of a thinkpad is quite different than most laptops. The hinges for the screen are much stronger and will last. So far I have had to glue the hinge back on to the case 3 times in 18 months on my wife's ideapad. Different price but also very different design and durability. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Thu Aug 22 14:07:54 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Thu, 22 Aug 2013 10:07:54 -0400 (EDT) Subject: laptop advice time... In-Reply-To: <20130822133535.GN12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130822030310.GB27852@amber> <20130822133535.GN12618@csclub.uwaterloo.ca> Message-ID: | From: Lennart Sorensen | I am pretty sure the keyboard on my W530 is chiclet style, but it is a | very nice keyboard to work with. Yes. Which prompts me to realize when I said we had a w530, I was wrong. It is a w520. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Thu Aug 22 14:12:38 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Thu, 22 Aug 2013 10:12:38 -0400 Subject: laptop advice time... In-Reply-To: References: <20130821222407.GM12618@csclub.uwaterloo.ca> Message-ID: <20130822141238.GP12618@csclub.uwaterloo.ca> On Thu, Aug 22, 2013 at 01:07:28AM -0400, D. Hugh Redelmeier wrote: > Yikes! > > W530 seems fine under Linux (Fedora). We haven't exploited the nvidia > chip. Well I certainly bought it expecting it to work. > Ditto for T520 (Ubuntu 12.04 LTS) (some undiagnosed freezes, mostly while > watching videos). Well if flash gets involved, crashes are to be expected. > Consider adding an mSATA SSD. The w530 and T520 have a slot for that > (unless you are using the slot for a wireless (cell) card). Oh there is a 16MB module in there already installed at the factory. Perhaps at some point if i see a good price I will put a bigger one in. > Tell us how that works out. I will make sure to do that. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Thu Aug 22 14:24:47 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Thu, 22 Aug 2013 10:24:47 -0400 Subject: 4K TVs anyone? In-Reply-To: References: Message-ID: <20130822142447.GQ12618@csclub.uwaterloo.ca> On Thu, Aug 22, 2013 at 07:56:12AM -0400, Giles Orr wrote: > There was some talk of these earlier. Tiger Direct is selling the 39" and > 50" Seiki 4K TVs for $700 and $1050 respectively: > > http://www.redflagdeals.com/deal/televisions/tigerdirectca-seiki-39-class-led-4k-ultra-hdtv-700-seiki-50-class-4k-led-hdtv-1050-cash-back/ > > I don't have a video card that could drive the damn thing, so I'm going to > pass. Too bad. Could pick up a GTX 650 card for about $90 that could drive it. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Thu Aug 22 18:20:51 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Thu, 22 Aug 2013 14:20:51 -0400 (EDT) Subject: OT war story / whine: more Windows 8 adventures Message-ID: [The grass is not greener on the other side of the fence.] Every once in a while, I do update stuff on the Windows installed on my various boxes. Almost the only thing I do on Windows is update things (sometimes including the BIOS). Why do I have Windows? Because it came with the hardware and I hate throwing anything out. Why do I update it? OCD, I guess. I have a notebook with Win8 that I am updating. First problem: how to find Windows Update. On the "start" screen you can start typing characters and the system will show you program choices containing that string (just like Ubuntu Unity or Fedora's Gnome). That gets me "ASUS Live Update" and "Software Updates". I don't want the former, and it turns out that the latter is some particular 3rd party updater that only knows about "Nuance PDF" crapware. You have to instead click on "Settings" before typing "upd". Windows Update seems to be a setting. When I click on Windows Update, I get some dumbed-down (compared with previous Windows' Windows Update) thing that gives me only one choice: to install one important update. So I say yes, install it. Moments later it whines that it hasn't been able to check for updates for a month (duh -- I knew that). So I said fine. And it checked and found a lot to update. Finally, I was in a place very much like previous Windows Updates. Where you get to select which updates to go for. I adjusted the selection and told it to go ahead with the update. Then it started downloading. There was a fair chunk to download. The progress bar was one of those that don't actually show progress (a band scanning across the bar, over and over). Since the progress bar is useless, they also tell you in text how much of the download has been done (why not in the progress bar???). But the text wasn't updated from 0% until all of a sudden, several minutes later, it jumped to 75% or so. In the middle of updating, I got an alert: Click To Run Microsoft Office Starter 2010 - English This product might be corrupted. If you experience problems with this product, open Program And Features in ControlPanel and repair the product [OK] What the heck is that, and why? Apparently it might be due to some Registry damage. Certainly nothing I did. So Windows Update seems to be worse in Win 8. Since that is almost all I use in Win8, I will extrapolate to say all of Win 8 is crap. Oh wait: there is another task that I've found hard in Win 8. Quiz: how do you shut down a Win 8 computer (politely)? One reason this comes up is that Windows Update wants me to restart the system. Windows defers some updating to shutdown time, and some until the next reboot of Windows. But if I want to reboot into Windows, and I do a restart, I have to watch like a hawk during the shutdown portion to catch grub and get it to boot Windows (not the default). When I rebooted, one of the "tiles" on the desktop, a headline, looked interesting ("Trudeau smoked pot after becoming MP"). So I clicked on it. Somehow, without showing me an article, it tells me I need to update a bunch of "apps" (presumably to see the article). It's 5 minutes later and I still haven't seen it. Why didn't Windows Update update them? Why do I want these apps anyway? OK, now it is finished and it has forgotten that I asked to see an article. Sheesh. These live tiles are pure distraction. Who knows what resources they are using. Even the "bing" app, for searching, is constantly updating to show me what's "trending". "Finance" alternates every two seconds between th S&P/TSX Composite index reading, and the same headline for a dumb article ("is raising a child easier financially than ever?). Ahh: if you right click on a tile, you can choose "turn live tile off". PS: maybe there is a disease going around. I find Ubuntu 13.04 and Fedora 19 update GUIs much worse than their predecessors'. So I just use the text-base commands. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Thu Aug 22 18:30:58 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Thu, 22 Aug 2013 14:30:58 -0400 Subject: OT war story / whine: more Windows 8 adventures In-Reply-To: References: Message-ID: <521658E2.4090803@rogers.com> D. Hugh Redelmeier wrote: > PS: maybe there is a disease going around. I find Ubuntu 13.04 and > Fedora 19 update GUIs much worse than their predecessors'. So I just > use the text-base commands. I run openSUSE and run KDE4 in KDE3 mode. I hate that new desktop that's default in KDE4. I guess the developers think fluff is more important than function. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Thu Aug 22 19:33:51 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Thu, 22 Aug 2013 15:33:51 -0400 (EDT) Subject: OT war story / whine: more Windows 8 adventures (fwd) Message-ID: [more censored communicatino from DCB] ---------- Forwarded message ---------- From: David Collier-Brown To: tlug-lxSQFCZeNF4 at public.gmane.org Cc: James Knott Date: Thu, 22 Aug 2013 14:53:35 -0400 Subject: Re: [TLUG]: OT war story / whine: more Windows 8 adventures Reply-To: davecb-0XdUWXLQalXR7s880joybQ at public.gmane.org On 08/22/2013 02:30 PM, James Knott wrote: > D. Hugh Redelmeier wrote: >> PS: maybe there is a disease going around. I find Ubuntu 13.04 and >> Fedora 19 update GUIs much worse than their predecessors'. So I just >> use the text-base commands. > I run openSUSE and run KDE4 in KDE3 mode. I hate that new desktop > that's default in KDE4. I guess the developers think fluff is more > important than function. > Everyone wanted to try an user interface experiment at the same time, thereby losing a LOVELY opportunity to move disgusted Windows users to one of the more GUI-friendly Linuxes. Thus far I'm using none of them, waiting for the market to shake out the no-hopers. --dave -- David Collier-Brown, | Always do right. This will gratify System Programmer and Author | some people and astonish the rest davecb-0XdUWXLQalXR7s880joybQ at public.gmane.org | -- Mark Twain (416) 223-8968 -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From moptop99-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 22 21:31:02 2013 From: moptop99-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Matt Price) Date: Thu, 22 Aug 2013 17:31:02 -0400 Subject: laptop advice time... In-Reply-To: <20130821194039.21abcd73259588080827b59d-MwcKTmeKVNQ@public.gmane.org> References: <20130821194039.21abcd73259588080827b59d@eol.ca> Message-ID: so, sounds like a whole raft of endorsements for another thinkpad! Does anyone out there have a system76 laptop? After some surfing, I'm wondering whether to give them a try this time around. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From andrej-igvx78u1SeH3fQ9qLvQP4Q at public.gmane.org Fri Aug 23 02:12:28 2013 From: andrej-igvx78u1SeH3fQ9qLvQP4Q at public.gmane.org (Andrej Marjan) Date: Thu, 22 Aug 2013 22:12:28 -0400 Subject: laptop advice time... In-Reply-To: References: <20130821222407.GM12618@csclub.uwaterloo.ca> Message-ID: On Thu, Aug 22, 2013 at 1:07 AM, D. Hugh Redelmeier wrote: > Consider adding an mSATA SSD. The w530 and T520 have a slot for that > (unless you are using the slot for a wireless (cell) card). > I was thinking about adding one to my own Thinkpad, then thought to check how full disk encryption plays with SSDs. Then my head exploded. Lots of controversy about whether it's ever safe, whether it's OK so long as you encrypt the device before using it for anything sensitive, whether you need robust TRIM support to not kill the device with full disk encryption, the sorry state of TRIM support in currently shipping distros... Is there really a concern here or did I just stumble on a bunch of outdated discussion? There's no way I'd use unencrypted storage of any sort in a laptop. As for Thinkpad keyboards, I used to *love* the old IBM-style keyboards, and I have one at home. Then I got a new machine with a chiclet keyboard at work, and now that I'm switching between them daily, I'm not 100% satisfied with either. The chiclets feel a little better than the old ones, but they include a few truly stupid layout decisions. -------------- next part -------------- An HTML attachment was scrubbed... URL: From jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org Fri Aug 23 02:55:48 2013 From: jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org (Jamon Camisso) Date: Thu, 22 Aug 2013 22:55:48 -0400 Subject: laptop advice time... In-Reply-To: References: <20130821222407.GM12618@csclub.uwaterloo.ca> Message-ID: <5216CF34.30507@utoronto.ca> On 22/08/13 10:12 PM, Andrej Marjan wrote: > Lots of controversy about whether it's ever safe, whether it's OK so long > as you encrypt the device before using it for anything sensitive, whether > you need robust TRIM support to not kill the device with full disk > encryption, the sorry state of TRIM support in currently shipping distros... I have a fully luks encrypted disk with TRIM support running Debian. It takes 3 things: 1) add these options to GRUB_CMDLINE_LINUX: allow-discards root_trim=yes 2) add "discard" to relevant partitions in /etc/crypttab 3) issue periodic fstrim commands. I do this once a day with cron Each distro seems to be different though, YMMV. Cheers, Jamon -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Fri Aug 23 12:02:11 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Fri, 23 Aug 2013 08:02:11 -0400 Subject: laptop advice time... In-Reply-To: References: <20130821222407.GM12618@csclub.uwaterloo.ca> Message-ID: <52174F43.50204@rogers.com> Andrej Marjan wrote: > I used to *love* the old IBM-style keyboards, and I have one at home. I'm typing this on an IBM "M" keyboard. It's excellent. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From rjonasz-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 23 14:06:21 2013 From: rjonasz-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Randy Jonasz) Date: Fri, 23 Aug 2013 10:06:21 -0400 Subject: laptop advice time... In-Reply-To: References: <20130821194039.21abcd73259588080827b59d@eol.ca> Message-ID: On Thu, Aug 22, 2013 at 5:31 PM, Matt Price wrote: > so, sounds like a whole raft of endorsements for another thinkpad! > Does anyone out there have a system76 laptop? After some surfing, I'm > wondering whether to give them a try this time around. If you're looking for a desktop replacement I'd recommend the asus g75vw. I use one at work with Ubuntu and Windows 8. It can take 2 hard drives and has 4 slots for ram. Ubuntu just works with it. Randy -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From thoriumbr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 23 14:15:12 2013 From: thoriumbr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Mauro Souza) Date: Fri, 23 Aug 2013 11:15:12 -0300 Subject: laptop advice time... In-Reply-To: <52174F43.50204-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <20130821222407.GM12618@csclub.uwaterloo.ca> <52174F43.50204@rogers.com> Message-ID: On my previous job I had Thinkpads, from T40 to a T410. All run Linux fine, almost everything worked out of the box. My last one (T410) got half a litre cup of orange juice all over his keyboard while turned on and working hard. I was working on something I couldn't afford to lose, and I thought I had already lost the notebook. I got it under a running sink, dropped a lot of water on it (still powered on) and let it working hard until it got dry. It worked even better, because it cleaned the keyboard. I had it for 6 months since then, and never had any trouble with it. Sadly I changed jobs and had to return it. My new job gave me a Dell Inspiron, and I miss my Thinkpad a lot. I was even considering buying a T430S, but I won't for now, as I don't need to. Mauro http://mauro.limeiratem.com - registered Linux User: 294521 Scripture is both history, and a love letter from God. 2013/8/23 James Knott > Andrej Marjan wrote: > > I used to *love* the old IBM-style keyboards, and I have one at home. > > I'm typing this on an IBM "M" keyboard. It's excellent. > > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -------------- next part -------------- An HTML attachment was scrubbed... URL: From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Fri Aug 23 14:22:29 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Fri, 23 Aug 2013 10:22:29 -0400 Subject: laptop advice time... In-Reply-To: References: <20130821222407.GM12618@csclub.uwaterloo.ca> Message-ID: <20130823142229.GR12618@csclub.uwaterloo.ca> On Thu, Aug 22, 2013 at 10:12:28PM -0400, Andrej Marjan wrote: > I was thinking about adding one to my own Thinkpad, then thought to check > how full disk encryption plays with SSDs. Then my head exploded. > > Lots of controversy about whether it's ever safe, whether it's OK so long > as you encrypt the device before using it for anything sensitive, whether > you need robust TRIM support to not kill the device with full disk > encryption, the sorry state of TRIM support in currently shipping distros... TRIM helps performance, but other than that should not actually affect the lifespan of the device. > Is there really a concern here or did I just stumble on a bunch of outdated > discussion? There's no way I'd use unencrypted storage of any sort in a > laptop. > > As for Thinkpad keyboards, I used to *love* the old IBM-style keyboards, > and I have one at home. Then I got a new machine with a chiclet keyboard at > work, and now that I'm switching between them daily, I'm not 100% satisfied > with either. The chiclets feel a little better than the old ones, but they > include a few truly stupid layout decisions. Layout issues are always a problem. For my desktop I used to use the KT800 from keytronics, which had a large L shaped enter key and a small 9normal key size) backspace with '\' to the left of backspace. I have given up on ever really finding more keyboards like that and am now using the keytronic E03600U2 instead which is an exact layout clone of the IBM AT keyboard (except with windows keys added where one would expect them to be). I find the layout on my W530 to be quite good for a laptop, at least when you order it with the US layout. There is no helping the canadian french layout that so many stores in Canada seem to think they should sell these days. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Fri Aug 23 14:25:14 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Fri, 23 Aug 2013 10:25:14 -0400 Subject: laptop advice time... In-Reply-To: References: <20130821222407.GM12618@csclub.uwaterloo.ca> <52174F43.50204@rogers.com> Message-ID: <20130823142514.GS12618@csclub.uwaterloo.ca> On Fri, Aug 23, 2013 at 11:15:12AM -0300, Mauro Souza wrote: > On my previous job I had Thinkpads, from T40 to a T410. All run Linux fine, > almost everything worked out of the box. > > My last one (T410) got half a litre cup of orange juice all over his > keyboard while turned on and working hard. I was working on something I > couldn't afford to lose, and I thought I had already lost the notebook. > I got it under a running sink, dropped a lot of water on it (still powered > on) and let it working hard until it got dry. It worked even better, > because it cleaned the keyboard. I had it for 6 months since then, and > never had any trouble with it. Sadly I changed jobs and had to return it. > My new job gave me a Dell Inspiron, and I miss my Thinkpad a lot. I was > even considering buying a T430S, but I won't for now, as I don't need to. So the waterproof tray with the drain holes through the laptop actually work? I have never dared test it. My wife once spilled soy sauce in her old compaq laptop. It didn't like that at all. It did come back to life after I spent a couple of days cleaning every piece of the keyboard and mainboard and drying it all. i had to tae apart all the layers of the keyboard to clean out everything. What a mess. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Fri Aug 23 14:34:28 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Fri, 23 Aug 2013 10:34:28 -0400 Subject: laptop advice time... In-Reply-To: References: <20130821194039.21abcd73259588080827b59d@eol.ca> Message-ID: <20130823143428.GT12618@csclub.uwaterloo.ca> On Thu, Aug 22, 2013 at 05:31:02PM -0400, Matt Price wrote: > so, sounds like a whole raft of endorsements for another thinkpad! > Does anyone out there have a system76 laptop? After some surfing, I'm > wondering whether to give them a try this time around. Given I am very much not a fan of Ubuntu, I certainly see nothing great about them. :) Looking at the pictures they look pretty well made. They have some mistakes (like HDMI instead of displayport on the profesional laptop is not acceptable. Displayport is much more flexible for high res displays. HDMI is for consumers using a TV to watch a video). They also don't say which intel wifi module they use. That's important information. After all a 1000 is not the same as a 6300 or even a 6250. You would want the 6300 out of those ones. And max of 16GB ram in a pro model? Really? My W530 can hold 32GB ram. OK the W530 costs more, but also includes an nvidia quadro kepler GPU, not just intel graphics. With just their touchpad, I am not sure they they are doing the 3 button mouse X requires. Thinkpads of course have a 3 button pointer stick, as well as the 2 button touchpad which makes that easy. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Fri Aug 23 14:41:28 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Fri, 23 Aug 2013 10:41:28 -0400 (EDT) Subject: laptop advice time... In-Reply-To: <20130823142229.GR12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130821222407.GM12618@csclub.uwaterloo.ca> <20130823142229.GR12618@csclub.uwaterloo.ca> Message-ID: | From: Jamon Camisso | I have a fully luks encrypted disk with TRIM support running Debian. It | takes 3 things: | | 1) add these options to GRUB_CMDLINE_LINUX: allow-discards root_trim=yes | 2) add "discard" to relevant partitions in /etc/crypttab | 3) issue periodic fstrim commands. I do this once a day with cron I would have thought that 2 and 3 do the same job in different ways. 2 acts earlier, so 3 would be redundant. I admit that I don't really understand the subtleties of TRIM on different abstraction layers (real disk vs virtual decrypted disk). With luks, is there a simple one-to-one correspondence between encrypted and decrypted blocks? I would be surprised if discard and fstrim are both useful: one or the other should do the job. I don't know which is better, but some advocate fstrim over discard and I don't remember any advocating discard over fstrim. | From: Lennart Sorensen | TRIM helps performance, but other than that should not actually affect | the lifespan of the device. I don't think that that is correct. TRIM avoids useless copying, and all writes are likely to cause SSD wear. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Fri Aug 23 14:48:47 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Fri, 23 Aug 2013 10:48:47 -0400 Subject: laptop advice time... In-Reply-To: References: <20130821194039.21abcd73259588080827b59d@eol.ca> Message-ID: <20130823144847.GU12618@csclub.uwaterloo.ca> On Fri, Aug 23, 2013 at 10:06:21AM -0400, Randy Jonasz wrote: > If you're looking for a desktop replacement I'd recommend the asus > g75vw. I use one at work with Ubuntu and Windows 8. It can take 2 > hard drives and has 4 slots for ram. Ubuntu just works with it. But windows 8 is unusable without some add ons to restore a sane UI. And what a monster in size. Also appears to use Atheros wifi which is nowhere near as good as intel wifi. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Fri Aug 23 14:49:16 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Fri, 23 Aug 2013 10:49:16 -0400 Subject: laptop advice time... In-Reply-To: <20130823144847.GU12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130821194039.21abcd73259588080827b59d@eol.ca> <20130823144847.GU12618@csclub.uwaterloo.ca> Message-ID: <20130823144916.GV12618@csclub.uwaterloo.ca> On Fri, Aug 23, 2013 at 10:48:47AM -0400, Lennart Sorensen wrote: > On Fri, Aug 23, 2013 at 10:06:21AM -0400, Randy Jonasz wrote: > > If you're looking for a desktop replacement I'd recommend the asus > > g75vw. I use one at work with Ubuntu and Windows 8. It can take 2 > > hard drives and has 4 slots for ram. Ubuntu just works with it. > > But windows 8 is unusable without some add ons to restore a sane UI. > > And what a monster in size. > > Also appears to use Atheros wifi which is nowhere near as good as > intel wifi. You can buy it with windows 7 though. :) -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org Fri Aug 23 14:48:23 2013 From: jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org (Jamon Camisso) Date: Fri, 23 Aug 2013 10:48:23 -0400 Subject: laptop advice time... In-Reply-To: References: <20130821222407.GM12618@csclub.uwaterloo.ca> <20130823142229.GR12618@csclub.uwaterloo.ca> Message-ID: <52177637.2000805@utoronto.ca> On 23/08/13 10:41 AM, D. Hugh Redelmeier wrote: > | From: Jamon Camisso > > | I have a fully luks encrypted disk with TRIM support running Debian. It > | takes 3 things: > | > | 1) add these options to GRUB_CMDLINE_LINUX: allow-discards root_trim=yes > | 2) add "discard" to relevant partitions in /etc/crypttab > | 3) issue periodic fstrim commands. I do this once a day with cron > > I would have thought that 2 and 3 do the same job in different ways. > 2 acts earlier, so 3 would be redundant. > > I admit that I don't really understand the subtleties of TRIM on > different abstraction layers (real disk vs virtual decrypted disk). > > With luks, is there a simple one-to-one correspondence between encrypted > and decrypted blocks? > > I would be surprised if discard and fstrim are both useful: one or the > other should do the job. I don't know which is better, but some > advocate fstrim over discard and I don't remember any advocating > discard over fstrim. > > | From: Lennart Sorensen > > | TRIM helps performance, but other than that should not actually affect > | the lifespan of the device. > > I don't think that that is correct. TRIM avoids useless copying, and > all writes are likely to cause SSD wear. TRIM in /etc/fstab is generally considered a bad idea as it can run as many times as the filesystem does writes. Manually running fstrim requires that discards be allowed by both the kernel, and by the dm-crypt driver is my understanding. So all three options make for robust TRIM support, though you could do away with part 3 if you wanted to increase wear on the drive a bit. Lifespan ratings for SSDs are pretty high these days, I'd expect one to last just as long as spinning disks. I've had a 60GB for 3 years and it is still going strong. Cheers, Jamon -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Fri Aug 23 14:57:26 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Fri, 23 Aug 2013 10:57:26 -0400 Subject: laptop advice time... In-Reply-To: References: <20130821222407.GM12618@csclub.uwaterloo.ca> <20130823142229.GR12618@csclub.uwaterloo.ca> Message-ID: <20130823145726.GW12618@csclub.uwaterloo.ca> On Fri, Aug 23, 2013 at 10:41:28AM -0400, D. Hugh Redelmeier wrote: > I would have thought that 2 and 3 do the same job in different ways. > 2 acts earlier, so 3 would be redundant. > > I admit that I don't really understand the subtleties of TRIM on > different abstraction layers (real disk vs virtual decrypted disk). > > With luks, is there a simple one-to-one correspondence between encrypted > and decrypted blocks? > > I would be surprised if discard and fstrim are both useful: one or the > other should do the job. I don't know which is better, but some > advocate fstrim over discard and I don't remember any advocating > discard over fstrim. My understanding is that using fstrim from cron regularly is more efficient since you just scan the filesystem for free space and do large trim operations. Using discard means every time a block is erased that block is also trimmed, which on some SSDs cause the SSD to do a garbage collection sweep which can take a while. At least that's how I understood it. > | From: Lennart Sorensen > > | TRIM helps performance, but other than that should not actually affect > | the lifespan of the device. > > I don't think that that is correct. TRIM avoids useless copying, and > all writes are likely to cause SSD wear. TRIM tells the SSD that this block is deleted, and can be erased and put in the free pool. After all when you delete a file, the blocks are marked free in the filesystem, but you don't go overwriting with zeroes or anything in general, and the disk has no idea that the block is never going to be read again. That is what TRIM is for. Let the disk know that you will never want to read this block's data again and that it can be erased. If you do ever read it, you don't care what the contents is (so it will probably be all zeroes or all ones), until you actually write to it again. Having more erased blocks around makes it easier for the SSD to write new data, since new data must be written to an erased block (perhaps after reading some of the existing data in the old block that is being "updated"). Once the data is written to a new block and it is mapped to the logical block number, then the old block is added to the blocks to be erased and placed in the free pool. So by telling the SSD that the block can be erased and placed in the free pool, you give the SSD more space to do writes to, before it must go and spend time erasing blocks that have old data in them. SSD's use NAND flash in general, which can only be written to after the whole block is erased. Erasing sets all the bits to 1, and writing clears some of those bits to 0. So you can only set bits to 1 if you do the whole block, while you can set bits to 0 individually. TRIM does not eliminate the read/modify/write cycle that writes smaller than a flash block require, it simply allows it to happen faster because the pool of already erased blocks is likely to be larger so bigger writes can be done in a row, before garbage collection and erasing must be done. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From thoriumbr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 23 15:07:19 2013 From: thoriumbr-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Mauro Souza) Date: Fri, 23 Aug 2013 12:07:19 -0300 Subject: OT war story / whine: more Windows 8 adventures (fwd) In-Reply-To: References: Message-ID: When Ubuntu natty came out with Unity, I left Ubuntu. I was using Ubuntu since dapper, when they used to deliver CDs to your door. I switched to Mint, and Cinnamon is great. Now I installed Ubuntu 13.10 again, installed Cinnamon on it, and was happy with the results. Until I changed jobs, got a dumbed down Dell, got mandatory Windows apps to run all the time... Now I run Ubuntu 13.04 on a Virtualbox inside Win7, and Cinnamon don't work as it should. It consumes up to 90% CPU doing nothing, and I discovered that the 3D driver from VirtualBox and Cinnamon don't talk friendly between them. So back to Unity... I kinda liked it, after getting used to it. I am thinking on installing Xfce or Fluxbox (from my old RedHat 5 days), but I don't have much time now... Mauro http://mauro.limeiratem.com - registered Linux User: 294521 Scripture is both history, and a love letter from God. 2013/8/22 D. Hugh Redelmeier > [more censored communicatino from DCB] > > ---------- Forwarded message ---------- > From: David Collier-Brown > To: tlug-lxSQFCZeNF4 at public.gmane.org > Cc: James Knott > Date: Thu, 22 Aug 2013 14:53:35 -0400 > Subject: Re: [TLUG]: OT war story / whine: more Windows 8 adventures > Reply-To: davecb-0XdUWXLQalXR7s880joybQ at public.gmane.org > > On 08/22/2013 02:30 PM, James Knott wrote: > > D. Hugh Redelmeier wrote: > >> PS: maybe there is a disease going around. I find Ubuntu 13.04 and > >> Fedora 19 update GUIs much worse than their predecessors'. So I just > >> use the text-base commands. > > I run openSUSE and run KDE4 in KDE3 mode. I hate that new desktop > > that's default in KDE4. I guess the developers think fluff is more > > important than function. > > > Everyone wanted to try an user interface experiment at the same time, > thereby losing a LOVELY opportunity to move disgusted Windows users to > one of the more GUI-friendly Linuxes. > > Thus far I'm using none of them, waiting for the market to shake out the > no-hopers. > > --dave > > -- > David Collier-Brown, | Always do right. This will gratify > System Programmer and Author | some people and astonish the rest > davecb-0XdUWXLQalXR7s880joybQ at public.gmane.org | -- Mark Twain > (416) 223-8968 > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -------------- next part -------------- An HTML attachment was scrubbed... URL: From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Fri Aug 23 15:53:15 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Fri, 23 Aug 2013 11:53:15 -0400 Subject: laptop advice time... In-Reply-To: <20130823142514.GS12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130821222407.GM12618@csclub.uwaterloo.ca> <52174F43.50204@rogers.com> <20130823142514.GS12618@csclub.uwaterloo.ca> Message-ID: <5217856B.6030501@rogers.com> Lennart Sorensen wrote: > My wife once spilled soy sauce in her old compaq laptop. It didn't like > that at all. It did come back to life after I spent a couple of days > cleaning every piece of the keyboard and mainboard and drying it all. > i had to tae apart all the layers of the keyboard to clean out everything. > What a mess. Back when I was a computer tech, I often washed off circuit boards with hot water and then dried them with compressed nitrogen. Never a problem. You can also use alcohol to flush out the water. Water will not harm electronic devices, though it's a good idea to keep is away from some mechanical devices.. In fact, circuit boards are often washed with steam and hot water on the production line. If you spill something corrosive, such as juice or soft drinks you want to rinse it off as quickly as possible. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Fri Aug 23 15:55:30 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Fri, 23 Aug 2013 11:55:30 -0400 Subject: laptop advice time... In-Reply-To: <20130823143428.GT12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130821194039.21abcd73259588080827b59d@eol.ca> <20130823143428.GT12618@csclub.uwaterloo.ca> Message-ID: <521785F2.3020001@rogers.com> Lennart Sorensen wrote: > With just their touchpad, I am not sure they they are doing the 3 button > mouse X requires. Thinkpads of course have a 3 button pointer stick, > as well as the 2 button touchpad which makes that easy. One reason I go with ThinkPads (my current one is an E520) is because they still come with a "TrackPoint" pointer. I hate those touch pads that so many computers come with. There's also one of those on my E520, but I have it disabled. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Fri Aug 23 16:03:51 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Fri, 23 Aug 2013 12:03:51 -0400 Subject: laptop advice time... In-Reply-To: <521785F2.3020001-bJEeYj9oJeDQT0dZR+AlfA@public.gmane.org> References: <20130821194039.21abcd73259588080827b59d@eol.ca> <20130823143428.GT12618@csclub.uwaterloo.ca> <521785F2.3020001@rogers.com> Message-ID: <20130823160351.GX12618@csclub.uwaterloo.ca> On Fri, Aug 23, 2013 at 11:55:30AM -0400, James Knott wrote: > One reason I go with ThinkPads (my current one is an E520) is because > they still come with a "TrackPoint" pointer. I hate those touch pads > that so many computers come with. There's also one of those on my E520, > but I have it disabled. Some Dell business oriented laptops now have a pointy stick in addition to the touchpad. They don't work anywhere close to as well as the thinkpad ones. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Fri Aug 23 16:17:21 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Fri, 23 Aug 2013 12:17:21 -0400 Subject: laptop advice time... In-Reply-To: <20130823160351.GX12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130821194039.21abcd73259588080827b59d@eol.ca> <20130823143428.GT12618@csclub.uwaterloo.ca> <521785F2.3020001@rogers.com> <20130823160351.GX12618@csclub.uwaterloo.ca> Message-ID: <52178B11.3070109@rogers.com> Lennart Sorensen wrote: > Some Dell business oriented laptops now have a pointy stick in addition > to the touchpad. They don't work anywhere close to as well as the > thinkpad ones. Yes, I know. I used to have to endure using a Dell notebook at work, a few years ago. I started using ThinkPads when I was working at IBM, back in the late '90s and have never bought other for myself. On the other hand, I have since had to work with other makes, including in support roles. The more I work with them, the more I appreciate ThinkPads. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From moptop99-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 23 21:57:25 2013 From: moptop99-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Matt Price) Date: Fri, 23 Aug 2013 17:57:25 -0400 Subject: Optimus vs. Iris vs. old-fashioned Intel Graphics (WAS: : laptop advice time...) Message-ID: Hey Folks, OK, so I feel I've narrowed it down to a Thinpad T430 or a System76 Galago Pro (very different machines). Before ordering I wanted to as what kind of experiences folks have had with the following graphics cards: - Intel HD 4000 (the default choice on the T430) - NVidia NVS 5400M (fancy choice on the T430, uses Optimus, which I guess requires bumblebee to work properly) - Intel Iris Pro 5200, the only choice on the Galago I'm not a gamer, and while I enoy watching movies on the laptop that's a very secondary funciton. However, my son has been playing a lot of minecraft and is 10 years old, so will be 13 or so before this laptop dies. He often asks to borrow my computer to play games, and I would lie him to be able to play at least a little. What do you thin? Do you have any of these cards, are you satisfied with them, are they well supported under linux? Thanks! Matt -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From rjonasz-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Sat Aug 24 00:06:24 2013 From: rjonasz-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Randy Jonasz) Date: Fri, 23 Aug 2013 20:06:24 -0400 Subject: laptop advice time... In-Reply-To: <20130823144847.GU12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130821194039.21abcd73259588080827b59d@eol.ca> <20130823144847.GU12618@csclub.uwaterloo.ca> Message-ID: On Fri, Aug 23, 2013 at 10:48 AM, Lennart Sorensen wrote: > On Fri, Aug 23, 2013 at 10:06:21AM -0400, Randy Jonasz wrote: >> If you're looking for a desktop replacement I'd recommend the asus >> g75vw. I use one at work with Ubuntu and Windows 8. It can take 2 >> hard drives and has 4 slots for ram. Ubuntu just works with it. > > But windows 8 is unusable without some add ons to restore a sane UI. > > And what a monster in size. > > Also appears to use Atheros wifi which is nowhere near as good as > intel wifi. Yeah it's funny. Ubuntu drives the Atheros wireless without a problem. The driver for windows 8 written by qualcom connects to wireless routers at work but my dd-wrt router at home is a no go. I have a usb wireless adapter so I can connect at home. :( -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hgibson-MwcKTmeKVNQ at public.gmane.org Sat Aug 24 15:30:32 2013 From: hgibson-MwcKTmeKVNQ at public.gmane.org (Howard Gibson) Date: Sat, 24 Aug 2013 11:30:32 -0400 Subject: laptop advice time... In-Reply-To: References: <20130821194039.21abcd73259588080827b59d@eol.ca> Message-ID: <20130824113032.08e799a50ca8649f48d6f376@eol.ca> On Thu, 22 Aug 2013 17:31:02 -0400 Matt Price wrote: > so, sounds like a whole raft of endorsements for another thinkpad! > Does anyone out there have a system76 laptop? After some surfing, I'm > wondering whether to give them a try this time around. One more thought about my Lenovo. I tried using it to convert some LPs to MP3 files, using Audacity. I did not work. I am not sure what the problem was. It may have been using the microphone, rather than the microphone jack. I had to resurrect my old laptop to do the recording. -- Howard Gibson hgibson-MwcKTmeKVNQ at public.gmane.org howard.gibson-PadmjKOQAFnQT0dZR+AlfA at public.gmane.org jhowardgibson-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org http://home.eol.ca/~hgibson -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Sat Aug 24 16:09:03 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Sat, 24 Aug 2013 12:09:03 -0400 (EDT) Subject: forcing lower refresh rate? Message-ID: The Seiki monitor with "4k" resolution is inexpensive. But it can only refresh a full resolution signal at 30Hz. I want to see whether a 30Hz desktop is OK. So I'd like to try 30Hz with a current monitor. The Xorg.0.log says "Ranges: V min: 56 V max: 76 Hz, H min: 30 H max: 81 kHz, PixClock max 175 MHz". This is from the monitors EDID data. But it can take an analog TV signal, surely at 60i and maybe 30p. I don't want to use analog for this test: too yucky resolution (even VGA isn't as clean as DVI). Is there a way to force X to ignore EDID data on DVI? Would 30Hz DVI likely work with the monitor? Oh: is 30Hz unpleasant for desktop use? The Seiki screen itself refresses at 60 or 120Hz, but the image can only be changed at 30Hz. I assume that 60i might be possible but not be better for the viewer than 30p. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Sat Aug 24 20:59:45 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Sat, 24 Aug 2013 16:59:45 -0400 Subject: laptop advice time... In-Reply-To: <20130824113032.08e799a50ca8649f48d6f376-MwcKTmeKVNQ@public.gmane.org> References: <20130821194039.21abcd73259588080827b59d@eol.ca> <20130824113032.08e799a50ca8649f48d6f376@eol.ca> Message-ID: <52191EC1.6030402@rogers.com> Howard Gibson wrote: > I did not work. No doubt. That's the worst way to do it. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From thomas.bruce.milne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Sun Aug 25 21:42:23 2013 From: thomas.bruce.milne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Thomas Milne) Date: Sun, 25 Aug 2013 17:42:23 -0400 Subject: Linux hackers rebuild internet from their Silicon Valley garage (Wired UK) Message-ID: http://www.wired.co.uk/news/archive/2013-08/22/coreos-new-linux -------------- next part -------------- An HTML attachment was scrubbed... URL: From thomas.bruce.milne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Sun Aug 25 21:46:00 2013 From: thomas.bruce.milne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Thomas Milne) Date: Sun, 25 Aug 2013 17:46:00 -0400 Subject: 4K TVs anyone? In-Reply-To: <20130822142447.GQ12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130822142447.GQ12618@csclub.uwaterloo.ca> Message-ID: On 2013-08-22 10:23 AM, "Lennart Sorensen" wrote: > > On Thu, Aug 22, 2013 at 07:56:12AM -0400, Giles Orr wrote: > > There was some talk of these earlier. Tiger Direct is selling the 39" and > > 50" Seiki 4K TVs for $700 and $1050 respectively: > > > > http://www.redflagdeals.com/deal/televisions/tigerdirectca-seiki-39-class-led-4k-ultra-hdtv-700-seiki-50-class-4k-led-hdtv-1050-cash-back/ > > > > I don't have a video card that could drive the damn thing, so I'm going to > > pass. Too bad. > > Could pick up a GTX 650 card for about $90 that could drive it. Is there even anything to watch with that resolution? > > -- > Len Sorensen > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -------------- next part -------------- An HTML attachment was scrubbed... URL: From colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Sun Aug 25 23:23:02 2013 From: colin.mc151-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Colin McGregor) Date: Sun, 25 Aug 2013 19:23:02 -0400 Subject: 4K TVs anyone? In-Reply-To: References: <20130822142447.GQ12618@csclub.uwaterloo.ca> Message-ID: On Sun, Aug 25, 2013 at 5:46 PM, Thomas Milne wrote: > > On 2013-08-22 10:23 AM, "Lennart Sorensen" > wrote: >> >> On Thu, Aug 22, 2013 at 07:56:12AM -0400, Giles Orr wrote: >> > There was some talk of these earlier. Tiger Direct is selling the 39" >> > and >> > 50" Seiki 4K TVs for $700 and $1050 respectively: >> > >> > >> > http://www.redflagdeals.com/deal/televisions/tigerdirectca-seiki-39-class-led-4k-ultra-hdtv-700-seiki-50-class-4k-led-hdtv-1050-cash-back/ >> > >> > I don't have a video card that could drive the damn thing, so I'm going >> > to >> > pass. Too bad. >> >> Could pick up a GTX 650 card for about $90 that could drive it. > > Is there even anything to watch with that resolution? Some of the computer game writers write for resolutions a bit higher than anything available at the time they are writing their games. But other than some games I would be (pleasantly) surprised if there is any "content" that we as normal civilians (ie: not employed by he content producers (TV/Movie studios) or various three/four letter government agencies) that could take full advantage of that resolution. Next question, how many xterms could one put on on screens like the above :-) . Colin McGregor -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Sun Aug 25 23:49:31 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Sun, 25 Aug 2013 19:49:31 -0400 (EDT) Subject: 4K TVs anyone? In-Reply-To: References: <20130822142447.GQ12618@csclub.uwaterloo.ca> Message-ID: | From: Thomas Milne | Is there even anything to watch with that resolution? My desktop. It's crowded at 2560x1600. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From stimur-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Mon Aug 26 02:20:40 2013 From: stimur-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Tim Sattarov) Date: Sun, 25 Aug 2013 22:20:40 -0400 Subject: 4K TVs anyone? In-Reply-To: References: <20130822142447.GQ12618@csclub.uwaterloo.ca> Message-ID: <521ABB78.9090605@gmail.com> On 25/08/13 05:46 PM, Thomas Milne wrote: > > > Is there even anything to watch with that resolution? > > Sure, http://www.youtube.com/results?search_query=4k+video&oq=4k+video&gs_l=youtube.3..0l10.1318.2991.0.3369.8.5.0.3.3.0.134.501.3j2.5.0...0.0...1ac.1.11.youtube.xIXKutXsU5A Tim -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Mon Aug 26 14:17:02 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Mon, 26 Aug 2013 10:17:02 -0400 Subject: 4K TVs anyone? In-Reply-To: References: <20130822142447.GQ12618@csclub.uwaterloo.ca> Message-ID: <20130826141702.GY12618@csclub.uwaterloo.ca> On Sun, Aug 25, 2013 at 05:46:00PM -0400, Thomas Milne wrote: > Is there even anything to watch with that resolution? Digital photographs? Your desktop? I don't know. :) -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Mon Aug 26 14:24:44 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Mon, 26 Aug 2013 10:24:44 -0400 Subject: Linux hackers rebuild internet from their Silicon Valley garage (Wired UK) In-Reply-To: References: Message-ID: <20130826142444.GZ12618@csclub.uwaterloo.ca> On Sun, Aug 25, 2013 at 05:42:23PM -0400, Thomas Milne wrote: > http://www.wired.co.uk/news/archive/2013-08/22/coreos-new-linux That headline is rather off the mark. They want to deal with a common but specific type of server use. That hardly qualifies as rebuilding the internet. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Mon Aug 26 14:41:25 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Mon, 26 Aug 2013 10:41:25 -0400 Subject: forcing lower refresh rate? In-Reply-To: References: Message-ID: <20130826144125.GA12618@csclub.uwaterloo.ca> On Sat, Aug 24, 2013 at 12:09:03PM -0400, D. Hugh Redelmeier wrote: > The Seiki monitor with "4k" resolution is inexpensive. But it can > only refresh a full resolution signal at 30Hz. > > I want to see whether a 30Hz desktop is OK. So I'd like to try 30Hz > with a current monitor. > > The Xorg.0.log says "Ranges: V min: 56 V max: 76 Hz, H min: 30 H max: > 81 kHz, PixClock max 175 MHz". This is from the monitors EDID data. > But it can take an analog TV signal, surely at 60i and maybe 30p. > I don't want to use analog for this test: too yucky resolution (even > VGA isn't as clean as DVI). Analog is handled through in internal scaler, which also takes care of the refresh rate. It is telling you that it will only accept refresh rates of 56 to 76Hz. So 30 isn't an option. > Is there a way to force X to ignore EDID data on DVI? Would 30Hz DVI > likely work with the monitor? In this case no. > Oh: is 30Hz unpleasant for desktop use? The Seiki screen itself > refresses at 60 or 120Hz, but the image can only be changed at 30Hz. > I assume that 60i might be possible but not be better for the viewer > than 30p. No idea if it would be unpleasant. Certainly LCD screens don't have the flicker issue that lower refresh rates caused on CRTs, so really the only thing should be more sluggish reponse to input and changes on the screen. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From thomas.bruce.milne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Mon Aug 26 15:45:07 2013 From: thomas.bruce.milne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Thomas Milne) Date: Mon, 26 Aug 2013 11:45:07 -0400 Subject: 4K TVs anyone? In-Reply-To: <20130826141702.GY12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130822142447.GQ12618@csclub.uwaterloo.ca> <20130826141702.GY12618@csclub.uwaterloo.ca> Message-ID: On Aug 26, 2013 10:14 AM, "Lennart Sorensen" wrote: > > On Sun, Aug 25, 2013 at 05:46:00PM -0400, Thomas Milne wrote: > > Is there even anything to watch with that resolution? > > Digital photographs? Your desktop? I don't know. :) Good point, I always think of just TV and gaming. > > -- > Len Sorensen > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -------------- next part -------------- An HTML attachment was scrubbed... URL: From thomas.bruce.milne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Mon Aug 26 15:49:37 2013 From: thomas.bruce.milne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Thomas Milne) Date: Mon, 26 Aug 2013 11:49:37 -0400 Subject: Linux hackers rebuild internet from their Silicon Valley garage (Wired UK) In-Reply-To: <20130826142444.GZ12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130826142444.GZ12618@csclub.uwaterloo.ca> Message-ID: On Aug 26, 2013 10:22 AM, "Lennart Sorensen" wrote: > > On Sun, Aug 25, 2013 at 05:42:23PM -0400, Thomas Milne wrote: > > http://www.wired.co.uk/news/archive/2013-08/22/coreos-new-linux > > That headline is rather off the mark. They want to deal with a common > but specific type of server use. > > That hardly qualifies as rebuilding the internet. > Oh ya, don't get me started on tech journalists and their misleading headlines. A lot of it really qualifies as trolling. Still worth reading in this case I think tho. > -- > Len Sorensen > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -------------- next part -------------- An HTML attachment was scrubbed... URL: From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Mon Aug 26 16:19:00 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Mon, 26 Aug 2013 12:19:00 -0400 Subject: Optimus vs. Iris vs. old-fashioned Intel Graphics (WAS: [TLUG]: laptop advice time...) In-Reply-To: References: Message-ID: <20130826161900.GB12618@csclub.uwaterloo.ca> On Fri, Aug 23, 2013 at 05:57:25PM -0400, Matt Price wrote: > so I feel I've narrowed it down to a Thinpad T430 or a System76 > Galago Pro (very different machines). Before ordering I wanted to as > what kind of experiences folks have had with the following graphics > cards: > > - Intel HD 4000 (the default choice on the T430) > - NVidia NVS 5400M (fancy choice on the T430, uses Optimus, which I > guess requires bumblebee to work properly) Most of the systems have a BIOS option to force one or the other to be active, so you could run linux using the nvidia all the time as far as I know. To save power using bumblebee or whatever replaced it some day to switch to the nvidia only when there is a reason to would be more efficient for sure. I still haven't had time to try it out on mine. > - Intel Iris Pro 5200, the only choice on the Galago It's probably a bit faster than the HD4000. Not sure how they compare. > I'm not a gamer, and while I enoy watching movies on the laptop that's > a very secondary funciton. However, my son has been playing a lot of > minecraft and is 10 years old, so will be 13 or so before this laptop > dies. He often asks to borrow my computer to play games, and I would > lie him to be able to play at least a little. > > What do you thin? Do you have any of these cards, are you satisfied > with them, are they well supported under linux? Well I still haven't tried linux on my new thinkpad, but I would expect it to do reasonable well. of course mine uses a quadro K2000M, which is about twice as powerful as the NVS 5400M. That was one of the reasons I went with a W530 rather than a T530. Of course anything is vastly better for gaming than intel video. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org Mon Aug 26 19:28:19 2013 From: kevin-4dS5u2o1hCn3fQ9qLvQP4Q at public.gmane.org (Kevin Cozens) Date: Mon, 26 Aug 2013 15:28:19 -0400 Subject: Linux hackers rebuild internet from their Silicon Valley garage (Wired UK) In-Reply-To: References: Message-ID: <521BAC53.1070102@ve3syb.ca> On 13-08-25 05:42 PM, Thomas Milne wrote: > http://www.wired.co.uk/news/archive/2013-08/22/coreos-new-linux Hm... they are stripping the OS down to a bare minimum. That make me think of QnX. -- Cheers! Kevin. http://www.ve3syb.ca/ |"Nerds make the shiny things that distract Owner of Elecraft K2 #2172 | the mouth-breathers, and that's why we're | powerful!" #include | --Chris Hardwick -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Mon Aug 26 19:51:19 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Mon, 26 Aug 2013 15:51:19 -0400 Subject: Linux hackers rebuild internet from their Silicon Valley garage (Wired UK) In-Reply-To: <521BAC53.1070102-4dS5u2o1hCn3fQ9qLvQP4Q@public.gmane.org> References: <521BAC53.1070102@ve3syb.ca> Message-ID: <20130826195119.GC12618@csclub.uwaterloo.ca> On Mon, Aug 26, 2013 at 03:28:19PM -0400, Kevin Cozens wrote: > On 13-08-25 05:42 PM, Thomas Milne wrote: > >http://www.wired.co.uk/news/archive/2013-08/22/coreos-new-linux > > Hm... they are stripping the OS down to a bare minimum. That make me > think of QnX. There is no amount of stripping down of Linux that will make it like QNX. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Mon Aug 26 20:18:41 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Mon, 26 Aug 2013 16:18:41 -0400 (EDT) Subject: war story: another disk problem Message-ID: Last night I was reading slashdot on a MythTV server (it was handy at the time). I followed a link from slashdot to an unknown site, and my browser started acting odd: unresponsive, dimming. Of course I thought: malware attacking Firefox. I soon figured out the real cause: disk problems. These were made visible by the dmesg command. I tried to shut the machine down for a refreshing reboot, but the shutdown didn't work. A long press on the power button did. On the way back up, grub complained and stopped. So rebooting didn't work. I booted a live Ubuntu 12.04.2 dvd. The first hard drive was misbehaving. Not 100%: the kernel still read the partitioning Recognizing the drive: [ 3.886635] ata1.00: ATA-8: WDC WD20EARS-00MVWB0, 51.0AB51, max UDMA/133 [ 3.886639] ata1.00: 3907029168 sectors, multi 0: LBA48 NCQ (depth 31/32), AA [ 3.890606] ata1.00: configured for UDMA/133 [ 3.890699] scsi 0:0:0:0: Direct-Access ATA WDC WD20EARS-00M 51.0 PQ: 0 ANSI: 5 [ 3.890775] sd 0:0:0:0: [sda] 3907029168 512-byte logical blocks: (2.00 TB/1.81 TiB) [ 3.890799] sd 0:0:0:0: Attached scsi generic sg0 type 0 [ 3.890815] sd 0:0:0:0: [sda] Write Protect is off [ 3.890817] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00 [ 3.890832] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 3.956719] sda: sda1 sda2 sda3 sda4 < sda5 sda6 > [ 3.957070] sd 0:0:0:0: [sda] Attached SCSI disk Here's the first error, about 2 seconds later: [ 5.998775] ata1.00: exception Emask 0x50 SAct 0x1 SErr 0x280900 action 0x6 frozen [ 5.998778] ata1.00: irq_stat 0x08000000, interface fatal error [ 5.998780] ata1: SError: { UnrecovData HostInt 10B8B BadCRC } [ 5.998783] ata1.00: failed command: READ FPDMA QUEUED [ 5.998786] ata1.00: cmd 60/08:00:90:03:00/00:00:00:00:00/40 tag 0 ncq 4096 in [ 5.998786] res 40/00:04:90:03:00/00:00:00:00:00/40 Emask 0x50 (ATA bus error) [ 5.998788] ata1.00: status: { DRDY } [ 5.998791] ata1: hard resetting link Here's where the disk wakes (and gets another error): [ 6.497059] ata1.00: configured for UDMA/133 [ 6.497070] sd 0:0:0:0: [sda] [ 6.497071] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [ 6.497072] sd 0:0:0:0: [sda] [ 6.497073] Sense Key : Aborted Command [current] [descriptor] [ 6.497074] Descriptor sense data with sense descriptors (in hex): [ 6.497075] 72 0b 00 00 00 00 00 0c 00 0a 80 00 00 00 00 00 [ 6.497080] 00 00 03 90 [ 6.497082] sd 0:0:0:0: [sda] [ 6.497083] Add. Sense: No additional sense information [ 6.497084] sd 0:0:0:0: [sda] CDB: [ 6.497085] Read(10): 28 00 00 00 03 90 00 00 08 00 [ 6.497089] end_request: I/O error, dev sda, sector 912 [ 6.497092] Buffer I/O error on device sda, logical block 114 [ 6.497102] ata1: EH complete A moment later, a bunch of errors get logged. Here's the first bit: [ 6.511086] ata1.00: exception Emask 0x10 SAct 0x1 SErr 0x280100 action 0x6 frozen [ 6.511091] ata1.00: irq_stat 0x08000000, interface fatal error [ 6.511094] ata1: SError: { UnrecovData 10B8B BadCRC } [ 6.511098] ata1.00: failed command: READ FPDMA QUEUED [ 6.511105] ata1.00: cmd 60/08:00:90:03:00/00:00:00:00:00/40 tag 0 ncq 4096 in [ 6.511105] res 40/00:04:90:03:00/00:00:00:00:00/40 Emask 0x10 (ATA bus error) [ 6.511108] ata1.00: status: { DRDY } [ 6.511113] ata1: hard resetting link [ 7.000015] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300) [ 7.008673] ata1.00: configured for UDMA/133 [ 7.008689] sd 0:0:0:0: [sda] [ 7.008691] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [ 7.008692] sd 0:0:0:0: [sda] [ 7.008693] Sense Key : Aborted Command [current] [descriptor] [ 7.008695] Descriptor sense data with sense descriptors (in hex): [ 7.008697] 72 0b 00 00 00 00 00 0c 00 0a 80 00 00 00 00 00 [ 7.008702] 00 00 03 90 [ 7.008705] sd 0:0:0:0: [sda] [ 7.008707] Add. Sense: No additional sense information [ 7.008708] sd 0:0:0:0: [sda] CDB: [ 7.008709] Read(10): 28 00 00 00 03 90 00 00 08 00 [ 7.008715] end_request: I/O error, dev sda, sector 912 [ 7.008717] Buffer I/O error on device sda, logical block 114 [ 7.008725] ata1: EH complete [ 7.088674] ata1.00: exception Emask 0x10 SAct 0x3f SErr 0x280100 action 0x6 frozen [ 7.088679] ata1.00: irq_stat 0x08000000, interface fatal error [ 7.088683] ata1: SError: { UnrecovData 10B8B BadCRC } [ 7.088687] ata1.00: failed command: READ FPDMA QUEUED [ 7.088694] ata1.00: cmd 60/08:00:f8:06:e2/00:00:04:00:00/40 tag 0 ncq 4096 in [ 7.088694] res 40/00:1c:f8:07:53/00:00:07:00:00/40 Emask 0x10 (ATA bus error) [ 7.088697] ata1.00: status: { DRDY } [ 7.088700] ata1.00: failed command: READ FPDMA QUEUED [ 7.088706] ata1.00: cmd 60/02:08:fe:0f:53/00:00:07:00:00/40 tag 1 ncq 1024 in [ 7.088706] res 40/00:1c:f8:07:53/00:00:07:00:00/40 Emask 0x10 (ATA bus error) [ 7.088709] ata1.00: status: { DRDY } I powered off, wiggled the disk cables, and rebooted. The result wasn't different. I powered off, moved the SATA cable to another SATA socket on the motherboard. The live CD booted, saw the disk behaving and proceeded to fsck (all without my asking -- scary). I powered off, moved the SATA cable back to the original SATA socket on the motherboard. The live CD booted, saw the disk behaving. So: I declared victory, rebooted from the formerly bad disk, and left the field of battle. I hope that the problem doesn't reappear. What happened? - not software: pretty up-to-date Ubuntu 12.04 on the disk didn't even get to booting once the system was busted. - not heat: I left the machine off while I slept. The problem was still there when I booted the live CD in the morning. - possibly the disk drive had an intermittent fault - perhaps a marginal power supply. Symptoms of power supply problems can be subtle and intermittent. - perhaps a crappy motherboard (Gigabyte GA-P43T-ES3G). Another datapoint on the motherboard: a few months ago the on-board ethernet interface became unreliable and then reliably broken. - my best guess: some kind of SATA cable or connector failure. Perhaps corrosion that was cleared up by plugging and unplugging. -->> your theory goes here <<-- -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Mon Aug 26 20:28:55 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Mon, 26 Aug 2013 16:28:55 -0400 (EDT) Subject: Linux hackers rebuild internet from their Silicon Valley garage (Wired UK) In-Reply-To: <20130826195119.GC12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <521BAC53.1070102@ve3syb.ca> <20130826195119.GC12618@csclub.uwaterloo.ca> Message-ID: | From: Lennart Sorensen | On Mon, Aug 26, 2013 at 03:28:19PM -0400, Kevin Cozens wrote: | > On 13-08-25 05:42 PM, Thomas Milne wrote: | > >http://www.wired.co.uk/news/archive/2013-08/22/coreos-new-linux | > | > Hm... they are stripping the OS down to a bare minimum. That make me | > think of QnX. | | There is no amount of stripping down of Linux that will make it like QNX. I don't remember a single thing in the article that let me know what they were actually doing or thinking. The article is one of those "not even wrong" things. The only intriguing thing was that they seem to drop Greg K-H's name. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Wed Aug 28 01:48:02 2013 From: william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (William Muriithi) Date: Tue, 27 Aug 2013 21:48:02 -0400 Subject: Java multi CPU capabilities Message-ID: Evening, Just curious if anyone here has ever looked at getting Java to run on more than one CPU. I have looked around and concluded that's not possible natively. Posting more or less for confirmation. Would I have missed anything? Found it an odd problem for a application to have at this time, really its 2013 http://www.datadisk.co.uk/html_docs/java_app/jboss5/jboss5_tuning.htm Came across this and petty the best article I have seen about Java. Good evening. William -------------- next part -------------- An HTML attachment was scrubbed... URL: From ted.leslie-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Wed Aug 28 02:40:22 2013 From: ted.leslie-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (ted leslie) Date: Tue, 27 Aug 2013 22:40:22 -0400 Subject: Java multi CPU capabilities In-Reply-To: References: Message-ID: I know c# (ms, or mono), have concurrent garbage collection, so in this sense c# has some multiple processing running below it, I assume Java would too. There are many things in a CIL runtime or java JVM that can be concurrent, and I think where they get the best bang for the buck they do it. But they obviously have to worry about breaking legacy apps, in that the legacy app. may have a bug but it never gets exploited because the VM has done it serial, now its trying it concurrent. Plus, aside from concurrent GC, you will not get much more improvement really, as with java or c# you are generating close to the assembly/binary you do with C/C++, in some cases you are actually generating even faster code then c/c++, and you don't run c/c++ on "more then one cpu"(as its not a lang vm) unless you program it or use libs that do. So I guess, aside from rephrasing your question to be, why does Java not use more then one CPU for GC, I can only speak for c#, where it DOES, but I would have to say Java does to? if they don't, that's a shame. You could say the same type of question for : why doesn't C/C++ lib XYZ do more stuff concurrently (of course some do), or why X11/gnome/KDE doesn't do more concurrently ..... they should, but in many cases its old legacy stuff, with concurrency improvements bring about new bugs, and like gnome/kde etc doesn't have enough of those? :) For small tasks, sometimes one arch. may allow concurrent to be faster, another, its faster serialized. Or its faster if spread over 2 concurrent jobs, but divide it to 8, and its slower then if divided to 2. Raytracing, for example, a super concurrent able job, if you had a cpu with 1M+ cores, you would think it would raytrace well, but the overhead (on existing tech.) to assign all those jobs, then memory contention .... so it may be better with 256 cores. Its all very tricky stuff, especially when intel/amd/nvidia etc are improving on multicore tech currently. -tl On Tue, Aug 27, 2013 at 9:48 PM, William Muriithi wrote: > Evening, > > Just curious if anyone here has ever looked at getting Java to run on more > than one CPU. > > I have looked around and concluded that's not possible natively. Posting > more or less for confirmation. Would I have missed anything? > > Found it an odd problem for a application to have at this time, really its > 2013 > > http://www.datadisk.co.uk/html_docs/java_app/jboss5/jboss5_tuning.htm > > Came across this and petty the best article I have seen about Java. > > Good evening. > > William -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org Wed Aug 28 12:41:30 2013 From: jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org (Jamon Camisso) Date: Wed, 28 Aug 2013 08:41:30 -0400 Subject: Java multi CPU capabilities In-Reply-To: References: Message-ID: <521DEFFA.2010001@utoronto.ca> On 13-08-27 10:40 PM, ted leslie wrote: > So I guess, aside from rephrasing your question to be, why does Java > not use more then one CPU for GC, I can only speak for c#, > where it DOES, but I would have to say Java does to? if they don't, > that's a shame. http://www.oracle.com/technetwork/java/javase/gc-tuning-6-140523.html#available_collectors Parallel GC uses multiple CPUs: "On a machine with N processors the parallel collector uses N garbage collector threads; however, this number can be adjusted with a command line option (see below). On a host with one processor, the parallel collector will likely not perform as well as the serial collector because of the overhead required for parallel execution.... and usually performs significantly better than the serial collector when more than two processors are available." -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Wed Aug 28 13:55:12 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Wed, 28 Aug 2013 09:55:12 -0400 (EDT) Subject: Java multi CPU capabilities In-Reply-To: References: Message-ID: | From: William Muriithi | Just curious if anyone here has ever looked at getting Java to run on more | than one CPU. | | I have looked around and concluded that's not possible natively. What do you mean by "natively"? | Posting | more or less for confirmation. Would I have missed anything? | | Found it an odd problem for a application to have at this time, really its | 2013 | | http://www.datadisk.co.uk/html_docs/java_app/jboss5/jboss5_tuning.htm I don't know what you mean. Here's a sentence from this article that says Java can exploit mutiple CPUs: Having multiple CPU's works well with Java threads, as they don't have to wait for long before getting onto a CPU, however there can be a problem by using too many CPU's for a thread this is called processor affinity -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Wed Aug 28 14:50:49 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Wed, 28 Aug 2013 10:50:49 -0400 Subject: Java multi CPU capabilities In-Reply-To: References: Message-ID: <20130828145049.GD12618@csclub.uwaterloo.ca> On Tue, Aug 27, 2013 at 09:48:02PM -0400, William Muriithi wrote: > Just curious if anyone here has ever looked at getting Java to run on more > than one CPU. > > I have looked around and concluded that's not possible natively. Posting > more or less for confirmation. Would I have missed anything? > > Found it an odd problem for a application to have at this time, really its > 2013 > > http://www.datadisk.co.uk/html_docs/java_app/jboss5/jboss5_tuning.htm > > Came across this and petty the best article I have seen about Java. > > Good evening. java is NOT the application. It is the language and runtime for the application. If an application wants to use multiple CPUs, then the author of the application should write a threaded application. There is certainly research into making runtimes and languages that can automatically make some parts of the code run in parallel, but that isn't something you are likely to see in current production systems. So if your application written in java creates multiple threads, then it will use multiple CPUs just fine. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org Wed Aug 28 16:13:04 2013 From: james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org (James Knott) Date: Wed, 28 Aug 2013 12:13:04 -0400 Subject: Linux for Workgroups Message-ID: <521E2190.3020300@rogers.com> http://www.networkworld.com/news/2013/082613-linus-torvalds-celebrates-22-years-273176.html?source=NWWNLE_nlt_linux_2013-08-28 -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From ted.leslie-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Wed Aug 28 19:53:44 2013 From: ted.leslie-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (ted leslie) Date: Wed, 28 Aug 2013 15:53:44 -0400 Subject: Java multi CPU capabilities In-Reply-To: References: Message-ID: "processor affinity" i think it the term to "fix/improve" the issues, to which you have inefficient processor assignment. -tl On Wed, Aug 28, 2013 at 9:55 AM, D. Hugh Redelmeier wrote: > | From: William Muriithi > > | Just curious if anyone here has ever looked at getting Java to run on more > | than one CPU. > | > | I have looked around and concluded that's not possible natively. > > What do you mean by "natively"? > > | Posting > | more or less for confirmation. Would I have missed anything? > | > | Found it an odd problem for a application to have at this time, really its > | 2013 > | > | http://www.datadisk.co.uk/html_docs/java_app/jboss5/jboss5_tuning.htm > > I don't know what you mean. Here's a sentence from this article that > says Java can exploit mutiple CPUs: > > Having multiple CPU's works well with Java threads, as they don't > have to wait for long before getting onto a CPU, however there can > be a problem by using too many CPU's for a thread this is called > processor affinity > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Wed Aug 28 23:26:59 2013 From: william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (William Muriithi) Date: Wed, 28 Aug 2013 19:26:59 -0400 Subject: Java multi CPU capabilities In-Reply-To: References: Message-ID: > | Just curious if anyone here has ever looked at getting Java to run on more > | than one CPU. > | > | I have looked around and concluded that's not possible natively. > > What do you mean by "natively"? > Apparently Java has two types of switches, the green and native switch. The native can only use one kernel thread which essentially mean one CPU. > | Posting > | more or less for confirmation. Would I have missed anything? > | > | Found it an odd problem for a application to have at this time, really its > | 2013 > | > | http://www.datadisk.co.uk/html_docs/java_app/jboss5/jboss5_tuning.htm > > I don't know what you mean. Here's a sentence from this article that > says Java can exploit mutiple CPUs: > Totally see why I sound lost. I possibly don't what I am taking about but I have checked cacti graphs at work and all seem to max up on one CPU. Google a bit and you will see a lot of people having that problem. Java can use multiple CPU together for garbage collection but the application side, its only one CPU as far as I can tell > Having multiple CPU's works well with Java threads, as they don't > have to wait for long before getting onto a CPU, however there can > be a problem by using too many CPU's for a thread this is called > processor affinity > -- William > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -------------- next part -------------- An HTML attachment was scrubbed... URL: From william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 29 00:03:04 2013 From: william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (William Muriithi) Date: Wed, 28 Aug 2013 20:03:04 -0400 Subject: Java multi CPU capabilities In-Reply-To: <20130828145049.GD12618-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys@public.gmane.org> References: <20130828145049.GD12618@csclub.uwaterloo.ca> Message-ID: > java is NOT the application. It is the language and runtime for the > application. My bad. Agree, that a serious error on my side. >If an application wants to use multiple CPUs, then the > author of the application should write a threaded application. > But how do you achieve that if your application is restricted without a container that is only single kernel threaded? > There is certainly research into making runtimes and languages that > can automatically make some parts of the code run in parallel, but that > isn't something you are likely to see in current production systems. > That seem to be the case > So if your application written in java creates multiple threads, then > it will use multiple CPUs just fine. > Not necessary. Sure, you can have as many threads as you want in the container, but if that container just make a single kernel thread, you wouldn't be able to sprend the thread across more than one CPU. That's what I am observing on both openjdk and sun Java. Casually check any server running Java based system and you will see the whole application look like a single process to the operating system. How do you explain that? > -- > Len Sorensen > -- William > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -------------- next part -------------- An HTML attachment was scrubbed... URL: From ted.leslie-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 29 00:54:54 2013 From: ted.leslie-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (ted leslie) Date: Wed, 28 Aug 2013 20:54:54 -0400 Subject: Java multi CPU capabilities In-Reply-To: References: <20130828145049.GD12618@csclub.uwaterloo.ca> Message-ID: ps and top by default only show process not threads. There is opts to show threads. In mono I have written program that showed many 100s threads on a process and utilizing 4 cores. Maybe there is some reason the hardware you are working on wants to be super thread safe or something. I know gui are usually single threaded to prevent a lot of foot shooting. I would guess Java has been able to do multi thread concurrent on multicores for over 10 years. C# could and back then Java was more powerful in just about every way over c#. Definitely not the case now however. .tl On Aug 28, 2013 8:03 PM, "William Muriithi" wrote: > > > java is NOT the application. It is the language and runtime for the > > application. > My bad. Agree, that a serious error on my side. > > >If an application wants to use multiple CPUs, then the > > author of the application should write a threaded application. > > > But how do you achieve that if your application is restricted without a > container that is only single kernel threaded? > > There is certainly research into making runtimes and languages that > > can automatically make some parts of the code run in parallel, but that > > isn't something you are likely to see in current production systems. > > > That seem to be the case > > > So if your application written in java creates multiple threads, then > > it will use multiple CPUs just fine. > > > Not necessary. Sure, you can have as many threads as you want in the > container, but if that container just make a single kernel thread, you > wouldn't be able to sprend the thread across more than one CPU. > > That's what I am observing on both openjdk and sun Java. > > Casually check any server running Java based system and you will see the > whole application look like a single process to the operating system. How > do you explain that? > > -- > > Len Sorensen > > -- > William > > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -------------- next part -------------- An HTML attachment was scrubbed... URL: From william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 29 01:22:12 2013 From: william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (William Muriithi) Date: Wed, 28 Aug 2013 21:22:12 -0400 Subject: Java multi CPU capabilities In-Reply-To: References: <20130828145049.GD12618@csclub.uwaterloo.ca> Message-ID: > ps and top by default only show process not threads. There is opts to show threads. In mono I have written program that showed many 100s threads on a process and utilizing 4 cores. > Actually you are correct pstree. There even flags on PS to display the threads. That being said, a default Java setup seem to trigger outage if the CPU hit 100%. Since most of the system have 4 CPU that shouldnt be the case till around 400% Isn't this correct or am I wrong here too? > Maybe there is some reason the hardware you are working on wants to be super thread safe or something. I know gui are usually single threaded to prevent a lot of foot shooting. > I would guess Java has been able to do multi thread concurrent on multicores for over 10 years. C# could and back then Java was more powerful in just about every way over c#. Definitely not the case now however. > .tl > Interesting, you are petty lucky then. I don't think that's happening in my case and from what I can tell by extensive Googling, its a problem to a lot of people. Do you mind sharing the Java options you are using please? I could play around with it tomorrow and see what happen William > On Aug 28, 2013 8:03 PM, "William Muriithi" wrote: >> >> >> > java is NOT the application. It is the language and runtime for the >> > application. >> My bad. Agree, that a serious error on my side. >> >> >If an application wants to use multiple CPUs, then the >> > author of the application should write a threaded application. >> > >> But how do you achieve that if your application is restricted without a container that is only single kernel threaded? >> > There is certainly research into making runtimes and languages that >> > can automatically make some parts of the code run in parallel, but that >> > isn't something you are likely to see in current production systems. >> > >> That seem to be the case >> >> > So if your application written in java creates multiple threads, then >> > it will use multiple CPUs just fine. >> > >> Not necessary. Sure, you can have as many threads as you want in the container, but if that container just make a single kernel thread, you wouldn't be able to sprend the thread across more than one CPU. >> >> That's what I am observing on both openjdk and sun Java. >> >> Casually check any server running Java based system and you will see the whole application look like a single process to the operating system. How do you explain that? >> > -- >> > Len Sorensen >> > -- >> William >> > The Toronto Linux Users Group. Meetings: http://gtalug.org/ >> > TLUG requests: Linux topics, No HTML, wrap text below 80 columns >> > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -------------- next part -------------- An HTML attachment was scrubbed... URL: From ted.leslie-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 29 03:55:31 2013 From: ted.leslie-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (ted leslie) Date: Wed, 28 Aug 2013 23:55:31 -0400 Subject: Java multi CPU capabilities In-Reply-To: References: <20130828145049.GD12618@csclub.uwaterloo.ca> Message-ID: Don't use Java, just c# now a days. Do you have a small test program or something you can post? -tl On Wed, Aug 28, 2013 at 9:22 PM, William Muriithi wrote: > >> ps and top by default only show process not threads. There is opts to show >> threads. In mono I have written program that showed many 100s threads on a >> process and utilizing 4 cores. >> > Actually you are correct pstree. There even flags on PS to display the > threads. > > That being said, a default Java setup seem to trigger outage if the CPU hit > 100%. Since most of the system have 4 CPU that shouldnt be the case till > around 400% > > Isn't this correct or am I wrong here too? > > >> Maybe there is some reason the hardware you are working on wants to be >> super thread safe or something. I know gui are usually single threaded to >> prevent a lot of foot shooting. >> I would guess Java has been able to do multi thread concurrent on >> multicores for over 10 years. C# could and back then Java was more powerful >> in just about every way over c#. Definitely not the case now however. >> .tl >> > Interesting, you are petty lucky then. I don't think that's happening in my > case and from what I can tell by extensive Googling, its a problem to a lot > of people. > > Do you mind sharing the Java options you are using please? I could play > around with it tomorrow and see what happen > > William > >> On Aug 28, 2013 8:03 PM, "William Muriithi" >> wrote: >>> >>> >>> > java is NOT the application. It is the language and runtime for the >>> > application. >>> My bad. Agree, that a serious error on my side. >>> >>> >If an application wants to use multiple CPUs, then the >>> > author of the application should write a threaded application. >>> > >>> But how do you achieve that if your application is restricted without a >>> container that is only single kernel threaded? >>> > There is certainly research into making runtimes and languages that >>> > can automatically make some parts of the code run in parallel, but that >>> > isn't something you are likely to see in current production systems. >>> > >>> That seem to be the case >>> >>> > So if your application written in java creates multiple threads, then >>> > it will use multiple CPUs just fine. >>> > >>> Not necessary. Sure, you can have as many threads as you want in the >>> container, but if that container just make a single kernel thread, you >>> wouldn't be able to sprend the thread across more than one CPU. >>> >>> That's what I am observing on both openjdk and sun Java. >>> >>> Casually check any server running Java based system and you will see the >>> whole application look like a single process to the operating system. How >>> do you explain that? >>> > -- >>> > Len Sorensen >>> > -- >>> William >>> > The Toronto Linux Users Group. Meetings: http://gtalug.org/ >>> > TLUG requests: Linux topics, No HTML, wrap text below 80 columns >>> > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org Thu Aug 29 04:07:28 2013 From: hugh-pmF8o41NoarQT0dZR+AlfA at public.gmane.org (D. Hugh Redelmeier) Date: Thu, 29 Aug 2013 00:07:28 -0400 (EDT) Subject: Java multi CPU capabilities In-Reply-To: References: <20130828145049.GD12618@csclub.uwaterloo.ca> Message-ID: I don't use Java. Ted doesn't use Java. I think Lennart must have used Java but has been trying to expunge the memory ever since. So what we say is unreliable in that sense. But we each know a bunch of things about coumputer systems in general. | From: William Muriithi | > What do you mean by "natively"? | > | Apparently Java has two types of switches, the green and native switch. The | native can only use one kernel thread which essentially mean one CPU. I don't know why switches would be green or native. I hope that this is an irrelevant detail. | Totally see why I sound lost. I possibly don't what I am taking about but I | have checked cacti graphs at work and all seem to max up on one CPU. What do you mean by a cacti graph? A pretty presentation of performance monitoring? | Google a bit and you will see a lot of people having that problem. Java | can use multiple CPU together for garbage collection but the application | side, its only one CPU as far as I can tell What's "that problem"? Wack of exploitation of more than one core? As I google, I find more evidence of Java concurrency exploiting "multicore". See | From: William Muriithi | But how do you achieve that if your application is restricted without a | container that is only single kernel threaded? What do you mean by "container"? That has several quite different meanings in the Java world. As it is, I cannot understand your question. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org Thu Aug 29 04:12:59 2013 From: jamon.camisso-H217xnMUJC0sA/PxXw9srA at public.gmane.org (Jamon Camisso) Date: Thu, 29 Aug 2013 00:12:59 -0400 Subject: Java multi CPU capabilities In-Reply-To: References: <20130828145049.GD12618@csclub.uwaterloo.ca> Message-ID: <521ECA4B.5070905@utoronto.ca> On 13-08-29 12:07 AM, D. Hugh Redelmeier wrote: > What's "that problem"? Wack of exploitation of more than one core? This question is the most relevant thusfar. Without a description of a problem or an explanation of what led to this reasoning (about Java's multi-cpu capabilities) and this thread, all the original link entails is a foregone conclusion to a problem that none of us can characterize or help troubleshoot. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 29 04:46:48 2013 From: cbbrowne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Christopher Browne) Date: Thu, 29 Aug 2013 00:46:48 -0400 Subject: Java multi CPU capabilities In-Reply-To: References: Message-ID: The fact that the common JVMs are expected to behave properly on Certain Operating Systems that don't much like forking processes puts a certain amount of "crimp" in this, although I don't see people complaining too much that you need to use fork() in order to get the average C application to use multiple CPUs... In practice, I'm not sure that many users terribly much *care* if a single Java application harnesses all the CPUs on their systems; that tends to get covered nicely by such additional factors as: a) Composing a broader service using multiple Java applications; b) Making the system easier to scale up by having multiple instances of interesting Java applications As soon as you do those things, you spatter the system with a bunch of processes, and harness as many CPUs as you want to. It's a pretty common strategy to attain parallelism by partitioning problems so that you can throw it against multiple physical servers; that strategy works perfectly well at splitting across CPUs. If you choose a supremely monolithic implementation strategy for your system that makes that nearly impossible, I'm not sure I'd consider that Gosling's problem. -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Thu Aug 29 12:25:09 2013 From: william.muriithi-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (William Muriithi) Date: Thu, 29 Aug 2013 08:25:09 -0400 Subject: Java multi CPU capabilities In-Reply-To: References: <20130828145049.GD12618@csclub.uwaterloo.ca> Message-ID: On Aug 29, 2013 12:08 AM, "D. Hugh Redelmeier" wrote: > > I don't use Java. Ted doesn't use Java. I think Lennart must have > used Java but has been trying to expunge the memory ever since. > > So what we say is unreliable in that sense. But we each know a bunch > of things about coumputer systems in general. > Okay, I understand. > | > What do you mean by "natively"? > | > > | Apparently Java has two types of switches, the green and native switch. The > | native can only use one kernel thread which essentially mean one CPU. > > I don't know why switches would be green or native. I hope that this > is an irrelevant detail. > Hope so too. I may read more about it when I get a chance purely for curiosity. > > | Totally see why I sound lost. I possibly don't what I am taking about but I > | have checked cacti graphs at work and all seem to max up on one CPU. > > What do you mean by a cacti graph? A pretty presentation of > performance monitoring? > Petty much. Have set it up to monitor all kind of statistics. I usually look at it when a system get a problem in an attempt to find the root cause. It current monitor all CPU in a system > | Google a bit and you will see a lot of people having that problem. Java > | can use multiple CPU together for garbage collection but the application > | side, its only one CPU as far as I can tell > > What's "that problem"? Wack of exploitation of more than one core? > That was what initially lead me to investigate a bit. Not really a problem in that nothing is broken but a curious part of me wanted to make sense of the observations > As I google, I find more evidence of Java concurrency exploiting > "multicore". See > < http://docs.oracle.com/javase/tutorial/essential/concurrency/highlevel.html> > Interesting, I admit I am missing something here. Its really possible we have some setting wrong. If I ever find a solution, will update the list. > > | From: William Muriithi > > | But how do you achieve that if your application is restricted without a > | container that is only single kernel threaded? > > What do you mean by "container"? That has several quite different > meanings in the Java world. > Hmm, I didn't know that. Will read on all the meaning and clarify. > As it is, I cannot understand your question. > -- Okay my bad. Ya, with the links you shared, its more likely something inherent to our setup than the Java. Or even a misunderstanding of the statistics I correct from the systems. William > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -------------- next part -------------- An HTML attachment was scrubbed... URL: From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Thu Aug 29 13:26:44 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Thu, 29 Aug 2013 09:26:44 -0400 Subject: Java multi CPU capabilities In-Reply-To: References: Message-ID: <20130829132644.GE12618@csclub.uwaterloo.ca> On Thu, Aug 29, 2013 at 12:46:48AM -0400, Christopher Browne wrote: > The fact that the common JVMs are expected to behave properly on > Certain Operating Systems that don't much like forking processes puts > a certain amount of "crimp" in this, although I don't see people > complaining too much that you need to use fork() in order to get the > average C application to use multiple CPUs... Of course we don't complain, because we don't use fork. We use pthread_create of course. And even windows that doesn't have fork, does support creating threads. > In practice, I'm not sure that many users terribly much *care* if a > single Java application harnesses all the CPUs on their systems; that > tends to get covered nicely by such additional factors as: > > a) Composing a broader service using multiple Java applications; > b) Making the system easier to scale up by having multiple instances > of interesting Java applications > > As soon as you do those things, you spatter the system with a bunch of > processes, and harness as many CPUs as you want to. > > It's a pretty common strategy to attain parallelism by partitioning > problems so that you can throw it against multiple physical servers; > that strategy works perfectly well at splitting across CPUs. > > If you choose a supremely monolithic implementation strategy for your > system that makes that nearly impossible, I'm not sure I'd consider > that Gosling's problem. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Thu Aug 29 13:40:38 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Thu, 29 Aug 2013 09:40:38 -0400 Subject: Java multi CPU capabilities In-Reply-To: References: <20130828145049.GD12618@csclub.uwaterloo.ca> Message-ID: <20130829134038.GF12618@csclub.uwaterloo.ca> On Wed, Aug 28, 2013 at 08:03:04PM -0400, William Muriithi wrote: > My bad. Agree, that a serious error on my side. > > But how do you achieve that if your application is restricted without a > container that is only single kernel threaded? I so far can't find anything on google saying JVMs only support running threads on one CPU. I can only find things that say the opposite. > That seem to be the case > > Not necessary. Sure, you can have as many threads as you want in the > container, but if that container just make a single kernel thread, you > wouldn't be able to spread the thread across more than one CPU. > > That's what I am observing on both openjdk and sun Java. Are you telling me java is even dumber that I had thought it was? Really? That's pathetic. >From what I can find, there is supposed to be java thread pools and such that claim they work with the host CPUs to take advantage of them. > Casually check any server running Java based system and you will see the > whole application look like a single process to the operating system. How > do you explain that? I don't think I have any such thing around. Java is a 4 letter word after all. :) -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org Thu Aug 29 13:49:53 2013 From: lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org (Lennart Sorensen) Date: Thu, 29 Aug 2013 09:49:53 -0400 Subject: Java multi CPU capabilities In-Reply-To: References: <20130828145049.GD12618@csclub.uwaterloo.ca> Message-ID: <20130829134953.GG12618@csclub.uwaterloo.ca> On Thu, Aug 29, 2013 at 12:07:28AM -0400, D. Hugh Redelmeier wrote: > I don't use Java. Ted doesn't use Java. I think Lennart must have > used Java but has been trying to expunge the memory ever since. No I have tried being a sysadmin in the past trying to help developers install a version of java that would work with a given piece of shit java class provided by some third party that as usual (for java class developers) couldn't botehr to specify which revision of java they required. Add to that my serious dislike of object oriented code, and java has no hope of being appreciated by me. The existence and bizarre popularity of the garbage named eclipse hasn't helped the situation. > So what we say is unreliable in that sense. But we each know a bunch > of things about coumputer systems in general. I certainly know how it ought to work, and what my quick google searches say java does or should do. It all says it should work for multithreaded code. As long as more than one thread is actually trying to do something of course. Obviously having 200 threads with only one trying to do any work will only get you one cpu core busy. > I don't know why switches would be green or native. I hope that this > is an irrelevant detail. I don't even think I want to know what it means. -- Len Sorensen -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists From thomas.bruce.milne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 30 21:17:51 2013 From: thomas.bruce.milne-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Thomas Milne) Date: Fri, 30 Aug 2013 17:17:51 -0400 Subject: Slashdot: Linux: Netflix Comes To Linux Web Browsers Via 'Pipelight' Message-ID: Slashdot: Linux: Netflix Comes To Linux Web Browsers Via 'Pipelight' http://google.com/producer/s/CBIwl5OLigM -------------- next part -------------- An HTML attachment was scrubbed... URL: From psema4-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 30 21:55:48 2013 From: psema4-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Scott Elcomb) Date: Fri, 30 Aug 2013 17:55:48 -0400 Subject: Slashdot: Linux: Netflix Comes To Linux Web Browsers Via 'Pipelight' In-Reply-To: References: Message-ID: On Fri, Aug 30, 2013 at 5:17 PM, Thomas Milne wrote: > Slashdot: Linux: Netflix Comes To Linux Web Browsers Via 'Pipelight' > http://google.com/producer/s/CBIwl5OLigM > Meanwhile the FSF is asking investors to divest their stock: < http://www.defectivebydesign.org/divest-from-netflix> -- Scott Elcomb @psema4 on Twitter / Identi.ca / Github & more Atomic OS: Self Contained Microsystems http://code.google.com/p/atomos/ Member of the Pirate Party of Canada http://www.pirateparty.ca/ -------------- next part -------------- An HTML attachment was scrubbed... URL: From tjaviss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 30 22:14:40 2013 From: tjaviss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Tyler Aviss) Date: Fri, 30 Aug 2013 15:14:40 -0700 Subject: bargain? 13.3" ultrabook with 1920x1080 for $600 (today only) In-Reply-To: <52138F28.1070804-biY6FKoJMRdBDgjK7y7TUQ@public.gmane.org> References: <52138F28.1070804@dinamis.com> Message-ID: 1.4GB is actually pretty high for win7. Probably had some Mcafee/Norton security suite and other starts-on-boot crap as well... On Aug 20, 2013 8:47 AM, "CLIFFORD ILKAY" wrote: > On 13-08-19 01:19 , D. Hugh Redelmeier wrote: > >> >> > >> > [snip] > > - 4G RAM is a bit low these days and in the future. Probably not >> expandable. >> > I overheard a Canada Computers employee who was helping a mom and daughter > who had come in to purchase a notebook that even though the 4GB of RAM was > soldered on the motherboard and couldn't be upgraded, 4GB was more than > enough for Windows 7. He said, "Look, it's only using 1.4GB for Windows so > you have plenty more memory." Ouch! > > -- > Regards, > > Clifford Ilkay > > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/**Mailing_lists > -------------- next part -------------- An HTML attachment was scrubbed... URL: From tjaviss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org Fri Aug 30 22:21:12 2013 From: tjaviss-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Tyler Aviss) Date: Fri, 30 Aug 2013 15:21:12 -0700 Subject: Barely functioning HD, and seeking advice re: how to successfully record in blu-ray In-Reply-To: References: <000301ce9c8b$80112ec0$80338c40$@net> Message-ID: Yeah the freezing thing works (did for me many times), but mostly for something where the drive is stuck. If either the needle on the read head or the spindle hands, the contraction can help free it. Just be sure to put it in a ziplock etc when freezing, as condensation is not your friend! On Aug 19, 2013 9:06 AM, "Tim Sattarov" wrote: > On Mon, Aug 19, 2013 at 11:48 AM, D. Hugh Redelmeier > wrote: > > Interesting. > > actually, I found better explanation why could it help: > > http://superuser.com/questions/353910/why-does-freezing-your-hard-drive-sometimes-help-to-recover-data-technical-deta > > Tim > -- > The Toronto Linux Users Group. Meetings: http://gtalug.org/ > TLUG requests: Linux topics, No HTML, wrap text below 80 columns > How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists > -------------- next part -------------- An HTML attachment was scrubbed... URL: