Microsoft and Unix/Linux (Myths and IP)

[D. Hugh Redelmeier]

| From: Charles philip Chan <cpchan-rieW9WUcm8FFJ04o6PK0Fg at public.gmane.org>

| On 30 Dec 2006, james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org wrote:
| 
| > http://en.wikipedia.org/wiki/UCSD_p-System
| 
| Yes, I was reading that. It must have been really slow since the CPU
| instructions are expected to be executed in software rather than in
| hardware. I can't imagine running it on a 64k machine.

I never used the UCSD system.  So what I say is theoretical.

- the system was not tied to 8080.  It could run on the Apple II too
  (6502 CPU).  I think also on the PDP-11.  Western Digital also sold
  a system based on its own microprocessor (the same one used by DEC
  to implement the LSI-11).  So the system let you use different
  hardware (something UNIX/Linux users should value).

- on many 64k systems, CPU was not the scarcest resource.  Memory
  might be.  Usable applications might be.  Decent high-level
  languages might be.  Disk I/O might be.  The UCSD system addressed
  each of these to some extent.

- bastardized BASIC was the most widely used "high-level" language on
  micros at that time.  It was usually interpreteted from some kind of
  tokenized source code.  This ought to be much slower than p-code
  interpretation.

It is amazing how little CPU you need to get many tasks done.  I
learned how to program on a machine that could add two numbers in
about 300 microseconds.  I wrote an interpreter for a language much
like BASIC on that machine.  It was reasonable to use it!

We should be startled how we can use up all the CPU on machines like
my desktop (Athlon 64 X2 3800).

Here's a table of my guess at usable minimum CPU requirements
(measured in instructions/second) for some common tasks.  Of course
more is better.

10k	word processing
	programming, compiling
	accounting, games, accounting games
	(eg. IBM 1620)

100k	GUI (eg. GEOS)
	WYSIWYG word processing
	TCP/IP on internet(?)

1M	nicer GUI (68K systems)
	real-time sound processing
	usable photo editing
	web browsing(?)

1G	real-time video processing

10G	Vista(TM) :-) :-)
	software radio/TV tuner?
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