Path: utzoo!attcan!uunet!sco!seanf
From: seanf@sco.COM (Sean Fagan)
Newsgroups: comp.arch
Subject: Re: A simple question on RISC
Message-ID: <1688@scolex>
Date: 10 Nov 88 21:58:31 GMT
References: <76083@sun.uucp> <559@dms.UUCP> <1021@raspail.UUCP> <7819@winchester.mips.COM>
Reply-To: seanf@sco.COM (Sean Fagan)
Organization: The Santa Cruz Operation, Inc.
Lines: 27

In article <7819@winchester.mips.COM> cprice@winchester.UUCP (Charlie Price) writes:
>Saying that the 6600 (or any of the 6000 series) had
>integer multiply without any further explanation and then saying
>that it didn't have integer divide is wrong.
>To quote the "Control Data 6000 Series Computer Systems Reference Manual"
>Revision W (1-15-73):
>
[to multiply integers, convert to floating point, then back]

The CDC Cyber 170 machines (which were, essentially, 7600's) did integer
multiply, in hardware, without having to convert to FP and back.  However,
you could only multiply 48-bit integers (that is, exponent equal to 0).
They still didn't have a divide instruction, although COMPASS *did* provide
one (as a "micro," but it trashed you source registers and a B register or
two (I forget, sorry)).

And, of course, Cray's don't have divides at all.  Does anybody besides me
get the impression that Seymour don't like 'em? 8-)

>Charlie Price    cprice@mips.com        (408) 720-1700
>MIPS Computer Systems / 928 Arques Ave. / Sunnyvale, CA   94086


-- 
Sean Eric Fagan  | "Engineering without management is *ART*"
seanf@sco.UUCP   |     Jeff Johnson (jeffj@sco)
(408) 458-1422   | Any opinions expressed are my own, not my employers'.