You might be surprised to learn that electronic analog computers are still being made. Afaik, the only company is Comdyna, <http://www.comdyna.com>. I'm not advertising them, but I do think Ray deserves credit. I do hope his knowledge of how to build good ones is being preserved for posterity...
One class of mechanical devices not widely recognized is mechanical, but their essential operation is binary. It might be fun to discuss such mechanisms.
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The teleprinters (Teletype [tm] in the USA, also Kleinschmidt, Creed in the U.K. (others?)) were, of course, partly binary. Keystrokes...
