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From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: net.micro,net.arch
Subject: Re: 386 Family Products
Message-ID: <6112@utzoo.UUCP>
Date: Mon, 4-Nov-85 19:24:34 EST
Article-I.D.: utzoo.6112
Posted: Mon Nov  4 19:24:34 1985
Date-Received: Mon, 4-Nov-85 19:24:34 EST
References: <129@intelca.UUCP> <392@aum.UUCP> <225@l5.uucp> <533@scirtp.UUCP>, <2353@ukma.UUCP>
Organization: U of Toronto Zoology
Lines: 33

> >...  What can it [the 386] do that the 68020 can't do better?	
> 
> Run several MS-DOS programs simultaneously with full 8086 compatibility,
> with each program in its very own 1 MByte address space.

Running old software is best done by recompiling portable source.  Or, in
the case of much MSDOS software, throwing it out and reimplementing.  The
parts about "simultaneous" and "very own address space" are nothing special.

If one really wants to make a decent machine [stipulating that the 386 is
such, I haven't got full specs yet] act like a bunch of brain-damaged ones,
consider the awesome inefficiency of emulating things like screen updates
one instruction at a time.  (Or does the 386 have some better hooks for
emulating memory-mapped virtual i/o devices?)  Yes, Virginia, there are
MSDOS programs that do their own screen updates.  Lots of them.

> Or how about running a program that requires 64 terabytes of memory?

Name one.  Name one disk with enough space to serve as backing store, too.
Note that you can't exploit that space without resorting to the disastrously
inefficient "large model" code, either.  Practically all real 386 programs
are going to run "small model", which fortunately isn't much of a problem
when that means 32-bit addresses.

> By the way, do I note a bit of unwillingness to listen to someone (or
> something) just because he (it) is black?

No, you detect a strong note of skepticism about Intel processors, after
four (five if you count the 432) botches in a row.  Maybe the skepticism
is unjustified in this case; I reserve judgement until I see spec sheets.
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry