Path: utzoo!attcan!uunet!husc6!rutgers!apple!baum
From: baum@Apple.COM (Allen J. Baum)
Newsgroups: comp.arch
Subject: Re: non-binary hardware
Message-ID: <17234@apple.Apple.COM>
Date: 16 Sep 88 04:33:30 GMT
References: <1285@mcgill-vision.UUCP> <3473@phri.UUCP> <5718@utah-cs.UUCP> <655@calvin.EE.CORNELL.EDU> <2997@pt.cs.cmu.edu>
Reply-To: baum@apple.UUCP (Allen Baum)
Organization: Apple Computer, Inc.
Lines: 23

[]
>In article <2997@pt.cs.cmu.edu> lindsay@k.gp.cs.cmu.edu (Donald Lindsay) writes:
>
>There have been conferences on "multiple valued logic" for years.
>

There is some sort of proof, which I've seen, but don't remember details of,
that the optimal base for computation is e (2.71828...). The proof wasn't
very complicated, and I've forgotten what the measure is of 'best'. Anyway,
bay in the 50's and early 60's, it was believed by some that 3 was closer to 
'e' than 2, so the up and built some base 3 computers. There are some articles
about techniques in some of the very early 'Computer Design' magazines c.1960.

One of the techniques used was transformer coupled phase logic (called
parametrons??: Logic 'level's were not some voltage level, but the phase of an 
AC signal (in 120 degree increments). You could get some interesting logic
functions just by how you wired up a transformer (two input windings, one
output winding). I think the Russians may have built a beast like this.

Well, what goes around comes around. Someone recently posted a note in this
group about a patent filed by Seymour Cray recently, which is a GaAs gate
structure using 'phase' logic. (who says history is useless?)
--
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