Vacuum tube logic thing

From: John Lawson <>
Date: Mon Feb 2 22:06:45 2004

On Mon, 2 Feb 2004, William Donzelli wrote:

> I'll give this list a shot a something meat I have had for a while -
> maybe I can get a nice trade.
> I have a big logic trainer that I would like to move on. It is pretty
> neat and unique for three reasons:
> 1) It is based on vacuum tubes. Inside are a number of 12AX7oids that do
> the work. I think this dates to the very late 1950s.
> 2) The logic is really odd. It is binary, but the logic levels are not
> voltage levels, but phases. Hell of a way to run a railroad, in my book.
> 3) Its Japanese. Yes, Japanese. Apparently part of an early minicomputer
> project that came out of Japan called Parametron.

  and a few others, two in Japanese and one that requires some kind of

 Google be yo fren'!

Quite the fascinating device - "based on the EDSAC" so I imagine it's
quite phase-dependent... the ENIAC had 10 seperate clock/buss lines, IIRC.

 There's also a transistor-like device bearing the name, and a Paramistor.
Based on Josephson-junction technology.


Received on Mon Feb 02 2004 - 22:06:45 GMT

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