Article View: net.arch
Article #2464Re: Re: 68k dbcc
From: kenny
Date: Tue, 06 May 1986 20:35
Date: Tue, 06 May 1986 20:35
34 lines
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1791 bytes
/* Written 9:35 am Apr 28, 1986 by jc@cdx27.UUCP in uiucdcsb:net.arch */
[...]
>Next they're going to make an add instruction that fails when either
>operand is zero, because "It's silly to waste time adding zero to a
>number."
[...]
>--
> John Chambers
[...]
/* End of text from uiucdcsb:net.arch */
I don't know about adds, but early versions of the Honeywell Level 66
mainframe had a character string move instruction that caused a mysterious
machine fault (``illegal instruction,'' if memory serves) if the programmer
attempted to move a zero-length string. Caused a lot of code looking like
if (length isn't zero) move in to out.
all over the system. Also caused some mysterious failures of tested code
(tested, that is, on newer machines) when it was installed on processors
that didn't have the fix for the bug.
Once again, the rationale was that ``nobody in his right mind would ever try
to ...''
Kevin Kenny
University of Illinois at Urbana-Champaign
UUCP: {ihnp4,pur-ee,convex}!uiucdcs!kenny
CSNET: kenny@UIUC.CSNET
ARPA: kenny@B.CS.UIUC.EDU (kenny@UIUC.ARPA)
"Yes, understanding today's complex world is a bit like having bees live in
your head, but there they are."
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxn!ihnp4!inuxc!pur-ee!uiucdcs!uiucdcsb!kenny From: kenny@uiucdcsb.CS.UIUC.EDU Newsgroups: net.arch Subject: Re: Re: 68k dbcc Message-ID: <5600047@uiucdcsb> Date: Tue, 6-May-86 16:35:00 EDT Article-I.D.: uiucdcsb.5600047 Posted: Tue May 6 16:35:00 1986 Date-Received: Thu, 8-May-86 21:45:09 EDT References: <133@cdx27.UUCP> Lines: 34 Nf-ID: #R:cdx27.UUCP:133:uiucdcsb:5600047:000:1194 Nf-From: uiucdcsb.CS.UIUC.EDU!kenny May 6 15:35:00 1986