Article View: comp.arch
Article #1762Re: Flash! 16 not power of 2! [really, CISC-to-the-max]
From: John Mashey
Date: Sun, 06 Aug 1989 23:40
Date: Sun, 06 Aug 1989 23:40
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In article <38139@stellar.UUCP> wright@sol.UUCP () writes:
....
>Honeywells were basically IBM ripoffs with a special Gray-to-binary
>instruction added so they could work on radars on the DEW line.
>They had some interesting features; not only did they have an
>execute (XEC) instruction that would execute the instruction at the
>effective address, they had execute double (XED) that would execute
>the two instructions starting at the effective address. Since the
....
>
>The other feature I've not seen elsewhere was the repeat instruction.
>This had the effect of repeatedly executing the instruction following
>the repeat (RPT), or the two instructions following (RPD) up to 256
>times. You could specify condition code settings that would end
>the iteration before the count ran out. There was even repeat-link,
....
This is really great stuff for placing the usual RISC-vs-CISC
wars in better context: compared to some of the older mainframe
architectures, 80386s, 68Ks, even S/360s and VAXen are about as RISCy as
they come.
In fact, this leads to an interesting question for the old-timers:
how about more reminiscing of instruction-set-architecture features of the
machines designed in the 50s and 60s, that have essentially
disapeared in those designed in the 70s and 80s...?
--
-john mashey DISCLAIMER: <generic disclaimer, I speak for me only, etc>
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!bu-cs!oliveb!apple!vsi1!wyse!mips!mash From: mash@mips.COM (John Mashey) Newsgroups: comp.arch Subject: Re: Flash! 16 not power of 2! [really, CISC-to-the-max] Message-ID: <24889@winchester.mips.COM> Date: 6 Aug 89 23:40:33 GMT References: <38139@stellar.UUCP> Reply-To: mash@mips.COM (John Mashey) Distribution: usa Organization: MIPS Computer Systems, Inc. Lines: 30