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From: pkr@maddog.sgi.com (Phil Ronzone)
Newsgroups: comp.arch
Subject: Re: IBM 370 Operand Alignment
Message-ID: <3520@odin.SGI.COM>
Date: 2 Feb 90 19:15:32 GMT
References: <9001250026.AA00720@ucbvax.Berkeley.EDU> <35102@mips.mips.COM> <3204@aimt.UU.NET> <3427@odin.SGI.COM> <35321@mips.mips.COM>
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In article <35321@mips.mips.COM> mash@mips.COM (John Mashey) writes:
>A relevant analysis can be found inGordon Bell & Allen Newell's "Computer
>Structures: Readings and Examples", McGraw-Hill, 1971.  In particular,
>pages 561-587 look at the S/360 family, and examine tradeoffs and
>cost/performance comparisons.  In particular, the hardwired 360/91
>had  good cost/performance characteristics, but the best of all was the 
>(hardwired) 360/44, which also lacked the variable-length instructions.
>ALso, the 360/91 (which had REAL scoreboarding, and was extermely complex,
>was shortly withdrawn from the market in favor of the 360/85, which if
>not the first, was certainly one of the earliest systems to use
>a cache memory.  This is a very useful chapter in many ways, as it also
>shows the methods used at the time to scale the same ISA across
>technologies.


They also really liked the 360/25, which was a double-microcode machine.
It had a "nano-code" engine which drove the microcode which implemented
the 360 instruction set. As I recall, they proposed a 360 family line
of 360/25's (MPs) and 360/44's as the best in terms of P/P.


------Me and my dyslexic keyboard----------------------------------------------
Phil Ronzone   Manager Secure UNIX           pkr@sgi.COM   {decwrl,sun}!sgi!pkr
Silicon Graphics, Inc.               "I never vote, it only encourages 'em ..."
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