Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!ucsd!ucrmath!rhyde
From: rhyde@ucrmath.ucr.edu (randy hyde)
Newsgroups: comp.sys.apple2
Subject: Re: RISC Machines
Message-ID: <8977@ucrmath.ucr.edu>
Date: 30 Sep 90 05:14:56 GMT
References: <8139.apple.net@pro-angmar> <13963@smoke.BRL.MIL> <8971@ucrmath.ucr.edu> <13969@smoke.BRL.MIL>
Organization: University of California, Riverside
Lines: 40

I don't want to get started on a flame thrower war here, but a few of your
comments deserve response:

>> This history is bogus..
What is bogus about it?  Of course the 6800 was a knock-off of the 6800.
The designers who formed MOS Technologies defected from Motorola.  But the
6502 introduced many new memory addressing modes  (including true indexed
addressing modes) which made it easier to program.

>> RISC architectures are specifically designed to facilitate compiler code
generation...

Talk about bogus!  RISC instruction sets are designed to execute fast. Period.
Yes, they threw out addressing modes and instructions which have no need in
HLL processing.  They did not make the instruction sets easier to deal with
for compiler designers.  The National 32000 family is much easier to write
compilers for than any RISC architecture I know of, yet it is the epitome of
CISC.  If you don't have a highly optimizing compiler, RISC performance is
not very good.

>> The term "RISC" has more specific meaning...

To you, obviously.  If you ask 100 different people what RISC means, you'll
get 100 different answers.  No one really has a good definition concerning
RISC.  I generally stick to many registers and a load/store architecture.
That's the only definition that covers everything currently being called
RISC.  The 65xxx is definitely not a RISC chip under this definition.

>> At the time the labels "RISC" and "CISC" where not yet introduced.

No, back then "similar to the PDP-11" was what people used when they wanted
to describe what we call a CISC chip today.  The 6800 and 6502 were definitely
referred to as "PDP-11 like" as opposed to the 8080 which most people called
brain-dead.

As an aside, Bill Mensch, designer of the 65c816 is attempting to market his
new chips as Mr. RISC  (maximum/minimum register RISC).  This is total
hyperbole.  The '816 and '832 chips are not RISC by anyone's definition.
Simple, yes.  RISC, no.
*** Randy Hyde O-)