Some folks built logic gates out of Tinkertoys. I don't think they had to add any string, but I'm not certain. They later reproduced their device using Giant Tinkertoys for an audience.
My first computer (when I was very small) was mechanical, a DigiComp I. It was a 3- or 4-bit machine that could add, subtract, count by ones or twos (up or down) ... I don't remember whether it could multiply. It was plastic sliders and metal rods, and was operated by pushing and pulling one tab that served as what I now think of as the clock pin. All but one of the people I know who had one wish they could find another. IIRC, the one exception still has his.
It was a lovely distraction for a little while, but I was soon back to asking my father how one got from vacuum tubes, relays, and levers, to COBOL and the BatComputer. He could explain valves, binary, octal, and IBM punch-card encoding, and he could program COBOL and SOAP, but he couldn't explain the stuff in between.
Mechanical Digital Computing
My first computer (when I was very small) was mechanical, a DigiComp I. It was a 3- or 4-bit machine that could add, subtract, count by ones or twos (up or down) ... I don't remember whether it could multiply. It was plastic sliders and metal rods, and was operated by pushing and pulling one tab that served as what I now think of as the clock pin. All but one of the people I know who had one wish they could find another. IIRC, the one exception still has his.
It was a lovely distraction for a little while, but I was soon back to asking my father how one got from vacuum tubes, relays, and levers, to COBOL and the BatComputer. He could explain valves, binary, octal, and IBM punch-card encoding, and he could program COBOL and SOAP, but he couldn't explain the stuff in between.