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They are - I believe they’re electric rather than electronic, and theoretically can be powered by a hand crank. They also use a neat trick of a tube filled with
by implements 4y ago
They are - I believe they’re electric rather than electronic, and theoretically can be powered by a hand crank. They also use a neat trick of a tube filled with ball bearings with a one ball gap so only one key can be pressed at a time (it fills the gap while pressed).
- avidiax 4y agoThis made me curious. Apparently this part of the machine was called the "compensation tube". But it's much more elegant than you've said. When you press 2 keys in quick succession, the 2nd key press is "saved" temporarily by latching a spring, so that as soon as the 1st key is done, the 2nd key is struck. It's essentially a 1 character buffer, which is apparently sufficient to give a very fluid typing feel. https://www.youtube.com/watch?v=xuPduBVGf8g https://www.youtube.com/watch?v=xuPduBVGf8g http://www.bitsavers.org/pdf/ibm/typewriter/selectric/CE_instructionManual.pdf http://www.bitsavers.org/pdf/ibm/typewriter/selectric/CE_ins...
- implements 4y agoThanks very much for the extra info.
- ebruchez 4y agoThat is correct. The Selectric (and Selectric II and III) are entirely electric. Later Selectric variations, like the Mag Card II, introduced electronics in a separate console or in a board fitting at the back of the machine, but the typewriter proper remained electromechanical, where the only electric part is the electric motor. The compensation tube is a cool design.