Path: utzoo!utgpu!water!watmath!clyde!att!whuts!homxb!houxs!beyer
From: beyer@houxs.UUCP (J.BEYER)
Newsgroups: comp.arch
Subject: Re: phase logic
Summary: Parametrons
Message-ID: <1000@houxs.UUCP>
Date: 28 Sep 88 13:05:14 GMT
References: 
Organization: AT&T Bell Laboratories, Holmdel
Lines: 20

In article , jdr+@andrew.cmu.edu (Jeff Rosenfeld) writes:
> There have recently been posts here concerning ideas involving the use of phase
> logic in digital(?) computers. This concept intrigues me but I am unable to
> locate any articles describing how such a thing might work.
> 

Do you mean parametrons? These were, if memory serves, devices with two magnetic
cores powered by an AC power supply. They  were a resonant circuit with two
stable states: One in one phase with respect to the power supply and one in
the other phase. You could change the phase by suitable inputs. The things
held promise for low-cost before transistors could be made for less than about
$10./each. But they were slow. As I recall, 100000 operations per second was an
upper bound, and 10000 to 20000 were more typical. I imagine they were quite
resistant to nuclear radiation. I believe the Japanese built some computers
using these. I would look them up in literature of the late 1950's or early
1960's.
-- 
Jean-David Beyer
A.T.&T., Holmdel, New Jersey, 07733
houxs!beyer