Relay computers - OR functionality

From: Joe R. <>
Date: Tue Sep 28 08:57:40 2004

  Speaking of germanium diodes, I have a LOT of DTL logic cards which use
them. If somebody's seriously interested in this stuff contact me off-list
and make me an offer. The cards are in like new condition and I can get
the sockets for them too.


At 02:55 PM 9/27/04 -0700, you wrote:
>On Mon, 2004-09-27 at 14:00, Dwight K. Elvey wrote:
>> You don't need the steering diodes if the lines that provide the
>> terms don't cross talk to other coils. This is pure relay logic
>> and works with AC relays as well as DC. The diodes are only
>> needed when you share complex terms that use the same stack of
>> contact terms but would otherwise cross talk. The diodes allow
>> one to optimize the number of contacts used by sharing common
>> terms.
>You're right, and while diodes would allow you to conjure up arbitrarily
>complex terms of even relay logic, it's also true that solid state
>diodes didn't exist back when relay calculators were The Latest Thing,
>if these questions are leading to 'why didn't they...'
>Though there's always selenium rectifiers, ugh. Besides being toxic,
>huge, hot, they are slow and terrible forward/reverse ratio, though
>likely faster than a relay. They've been around for a long time, I
>wonder how good they' be as a relay signal diode (shudder).
Received on Tue Sep 28 2004 - 08:57:40 BST

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