Simon / Relay clock rates / was Re: Computer in 1900,

Brent Hilpert hilpert at
Sat Feb 16 16:17:18 CST 2008

woodelf wrote:
> Gavin Melville wrote:
> > I've seen the stuff on the relay computer, and I suspect that simply
> > would not have worked in 1900, but works due to modern relays.

> We are talking high speed of  5? Hz for  relay computers.
> I am guessing a 1 HZ might practial for that era.

Just for a (partial) example, a year or two ago I breadboarded a 10-stage ring
counter from relays of late-40s/50s vintage while working on a completed design
of Simon*. Going purely by ear, I could clock it up to about 18Hz before it
started to falter.

* After the mention of Simon on the list a couple of years ago I set out to do
a completed design. This was done ( ) and
a simulator written, but I haven't built a complete physical implementation
(not enough relays on hand). The relay ring counter was a test of the timing

I've been meaning to mention this here for ages, but speaking of relay
computers, Simon, and machines with minimal instruction sets, if anybody feels
like a masochistic, tear-your-hair-out exercise in programming frustration, I'd
like to solicit programs to run in the Simon simulator (see link above).

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