Emulators of Classic Computers

From: Stan Barr <stanb_at_dial.pipex.com>
Date: Wed Jan 21 03:31:07 2004


William Donzelli <aw288_at_osfn.org> said:

> > ...this sounds as though it's the converse; this sounds as though tube
> > transit times are inconveniently _high_.
> >
> > So I don't get it.
> In theory, computing tubes would not use much power at all, so one could
> space the cathode-grid-plate structure very close, and get the super
> speeds due to the very short distances involved. Imagine tubes as small
> today's transistors - the speeds would be fantastic, as the electrons
> would speed right thru the micron of vacuum much faster that a micron of
> silicon.
> However, the real world hits the tubes far before element spacing gets
> this tiny. The breakdown voltage between the cathode and plate probably
> hits first - too close, and the electrons will simply jump over on their
> own, like a spark. Likewise, with very short distances, capacitance will
> become a big issue. The best conventional tubes top out somewhere around 4
> GHz, and these were only good for small amounts of power. They were a
> bastard to build, as well.
> So, in a perfect world, with no capacitance or power problems, tubes
> would be great.

See http://www.triodeel.com/area51.htm - if it still works.

Stan Barr  stanb_at_dial.pipex.com
The future was never like this!
Received on Wed Jan 21 2004 - 03:31:07 GMT

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