'Home' computer: Definition

From: William Donzelli <william_at_ans.net>
Date: Sun Jun 29 22:50:18 1997

> I remember someone saying in one post about MCMXXX and the response being
> *must have meant MCMLXXX* - why? Triode tubes (valves - I love that word)
> were around - Why couldn't you build a computer using tubes from the 30's.

Simply put, most (nearly 99.9%) toobs really do not like to work in a
digital fashion. They get "sleeping sickness" - when cut-off for a period
of time, electrons bunch up around the cathode (they are always emitted,
but can not get past the grid). This electron cloud, unfortuneately,
takes time to break apart after the grid bias turns the device on -
resulting in a horrible response time for any gate.

I suppose one could make ECL with vacuum techonology - keeping the digital
states between cut-off and saturation, but the price of extra parts
would be very large.

Only in the 1950s did manufacturers start to make toobs that behaved in
digital circuits.

William Donzelli
william_at_ans.net
Received on Sun Jun 29 1997 - 22:50:18 BST