Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!gem.mps.ohio-state.edu!samsung!aplcen!haven!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn)
Newsgroups: comp.sys.apple
Subject: Re: Apple's committment to the // line
Message-ID: <11434@smoke.BRL.MIL>
Date: 27 Oct 89 20:10:18 GMT
References: <8910161138.AA10844@trout.nosc.mil> <11322@smoke.BRL.MIL> <8192@microsoft.UUCP>
Reply-To: gwyn@brl.arpa (Doug Gwyn)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 24

In article <8192@microsoft.UUCP> brianw@microsoft.UUCP (Brian Willoughby) writes:
>The fact that [the 486 etc.] is based on old technology, and doesn't
>have true general purpose registers is only a small limiting factor
>- mostly the machine is so fast you don't notice the many restrictions.

>... why do you think that a 6502 ... couldn't run UNIX?

I didn't say it couldn't, although I do think the result would not be
worth the effort.  However, it DOESN'T run UNIX, and that is important
when you compare the value of different processor architectures.

In fact, I happen to think the 6502/65816 architecture is not really
better than the 8086 family's.  It is page-oriented, uses absolute
page 0 for special purposes, has only one register that really
qualifies as "general-purpose" (although you can't index with it),
and has a wildly nonorthogonal coupling between opcodes and addressing
modes.

There are sensible computer architectures, but the 65816 is not one
of them.  Check out MIPS or SPARC for typical examples of architectures
with all the structural advantages of the 6502 (actually, its only one
is its single-cycle execution) while avoiding its problems.

I own a IIGS, but not because I think it's a great CPU design.