15 Feb
2008
15 Feb
'08
7:09 a.m.
Hi
I will concede that it wasn't until the 1920's that tubes
were created that would have been useful for a computer.
Direct heated tubes would be difficult to use in any case
because any useful voltage level shifting would be needed
to be done by cathode followers. This would require an
independent supply for each filament.
There is still the option of externally heated filaments using
coal gas.
But I think the only practical computer of that time would
be relays.
The only really difficult part would be what to use for RAM.
Holding relays would reduce the power but cost would be
bad( as I'd suggested by using reed relays with bias magnets ).
Zuess had a mechanical memory but it never worked well.
To run at any speed, it bent or broke push rods.
He did have the best relay ALU I'd ever seen.
Dwight
From: dkelvey at hotmail.com
To: cctalk at classiccmp.org
Date: Fri, 15 Feb 2008 06:45:25 -0800
Subject: RE: Oldest operational computer was Re: cctalk Digest, Vol 54, Issue
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From: cc at informatik.uni-stuttgart.de
On Thu, 14 Feb 2008, dwight elvey wrote:
Hi
Low gain and high capacitance between grid and plate
made them hard to use for RF. Audio amplification
could be used after a diode detector.
Dwight
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Climb to the top of the charts! Play the word scramble challenge with star power.
http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_jan I wish to make a correction. The tubes were
called audions and were
not made until 1906. Low gain made them hard to use for radio uses
"Audion" and "hard to use for radio" is a contradiction...
Christian