Droid issues - Legacy Bash IFS var clobbering VLIW offset?

Lennart Sorensen lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org
Fri Nov 25 15:28:59 UTC 2011


On Fri, Nov 25, 2011 at 08:30:58AM -0500, Russell Reiter wrote:
> The man who founded MS said who needs more than 640k or did he?
> 
> http://www.computerworld.com/s/article/9101699/The_640K_quote_won_t_go_away_but_did_Gates_really_say_it_

Ah the old 640k issue.  Yet another stupidity of the x86 design by intel.

The reset address is F...F0 on x86 processors.  That meant rom had to be
at the end of address space.  So that meant ram had to be somewhere else,
so might as well be at the begining, although actually IO is at the very
begining overlapping a few KB of the ram.

When you later increase the address space, having your rom at the end
of what used to be your address space is pretty inconvinient.

Intel designs before the x86 had selectable reset addresses and often
used 0.  This does make it harder to catch accesses to address zero
(which of often what NULL is defined to be after all).

I believe 68k based systems all had rom much earlier in the address space
which made it easier when the memory space went from 24 to 32bit since you
could just expand ram.  Of course many of those machines also had multiple
types of ram in different ranges and the OS knew how to work with that,
although most I have looked at had the generic memory at the end of
address space so it was easy to expand later when the address space grew.

Of course the 640k value was simply because of where the graphics card
rom was places.  Text only monochrome systems could have 704k or sometimes
even more since they didn't have a rom right after 640k.

> Retrograde or cornerstone of a plain language type? Like latin
> languages as opposed to English, French or German and then there's
> this french language signs only thing.
> 
> If people have a right to agree to disagree, they should have the
> right for that message to get through.
> 
> Hell if I can ever get my matter transmitter working, I'll be pitching
> lineotype slugs at this list.

-- 
Len Sorensen
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