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From: johnw@astroatc.UUCP (John F. Wardale)
Newsgroups: comp.arch
Subject: Re: The 360 was a design landmark  (360 vs vax)
Message-ID: <418@astroatc.UUCP>
Date: Wed, 31-Dec-69 18:59:59 EDT
Article-I.D.: astroatc.418
Posted: Wed Dec 31 18:59:59 1969
Date-Received: Tue, 25-Aug-87 06:05:20 EDT
References: <855@tjalk.cs.vu.nl> <2683@hoptoad.uucp> <916@haddock.ISC.COM> <1035@bsu-cs.UUCP> <26312@sun.uucp> <1044@bsu-cs.UUCP> <1193@k.gp.cs.cmu.edu>
Reply-To: johnw@astroatc.UUCP (John F. Wardale)
Organization: Astronautics Technology Cntr, Madison, WI
Lines: 43
Summary: 360/370 designed to become faster than vaxen are

In article <1193@k.gp.cs.cmu.edu> lindsay@k.gp.cs.cmu.edu (Donald Lindsay) writes:
>you want. In fact, the 360 is something of a RISC machine by latter
>standards.
Whoooooo!!!!!   The 360/370 has some instructions that almost
define the limits for a "CISC"

On your side...see below

>As for 12 bit offsets: ...increased code density.
>...  The VAX carried this same idea further.

>To reiterate, it (the 360) changed the world, for the better. Be kind.

So...What did the Vax get for all its architectual contortions.
Dare I start a 370-vs-Vax debate??

The 360 designers saw fit (or did they just guet luckie...I don't
think so!) to design *PIPELINING-CAPABILITY* into the 360.
12-bit offsets, EBCDIC, and IBM-marketing asside, THE *MAJOR*
reason the ancint 360/370 stuff is still alive, while DEC's vaxen
are falling by the wayside (despite DES's best efforts) is that
360's *CAN* be pipelined (tho not necessarily real easily) and
VAXen can't!  

The 1st byte of each 370 instruction tells you the length of the
instruction!  On a VAX, you have to gather *ALL* the operands
(0, 1, 2, or 3!) before you can find the start of the next
instruction!

Top 370 designes top out at 20 MIPS (or is it more now?)
Top Vax design is maybe 8 MIPS.

The point is that despite moderate-size misteakes, the 360 is a
relatively OK design, and was fanaminally excellent for the early
1960's!!!!!!!!

(And I'm definataly a non-IBM type person!)

-- 
					John Wardale
... {seismo | harvard | ihnp4} ! {uwvax | cs.wisc.edu} ! astroatc!johnw

To err is human, to really foul up world news requires the net!