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