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From: jthomas@nmsu.edu (James Thomas)
Newsgroups: comp.arch
Subject: Re: 1620 (Was Odd word size?  Word size?  Word?  Definitely Odd.)
Message-ID: <214@opus.NMSU.Edu>
Date: 8 Oct 90 19:50:23 GMT
References: <270CB430.21156@ics.uci.edu>
	<GOTTLIEB.90Oct5150853@allan.ultra.nyu.edu> <38885@cos.com>
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In-reply-to: fetter@cos.com's message of 8 Oct 90 05:39:04 GMT

In article <38885@cos.com> fetter@cos.com (Bob Fetter) writes:

bob>   Weren't the add tables provided as an extra feature, this feature named
bob> CADET?  If memory serves me, the 1620 itself had no add hardware (which, it
bob> being decimal based, makes some kind of sense), so CADET was described as
bob> a "feature".  CADET itself, of course, standing for Can't Add, Doesn't Even
bob> Try.

I suppose one might call the add and multiply tables an "extra feature".
But they were standard.  The add was done by tacking the two source digits
onto the address 003nm.  The digit at that address was the sum, with a flag
bit indicating carry (requiring an extra add cycle next digit).
Recomplement cycles were painful :-)

Jim