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Oldest computer you've used for "real work"?
03-10-2015, 02:53 AM
Post: #21
RE: Oldest computer you've used for "real work"?
Interesting but would not work on a selectric, but a selectric is even easier you just need to sense either the 6 selection latches or the bails under the keyboard that where moved by the combination of the filter shaft and interposer under the key that was struck. On the first I/O mechanism, since it printed every time you struck a key, a block of contacts under the selection mechanism sensed the latches that where not pulled off the selection bail. The later mechanism that had the keyboard disconnected from the printer used the bails under the keyboard to move magnets over a board with reed switches on it. The selection mechanism in the selectric is essentially a mechanical digital to analog converter that converts the latches selected into 11 positions of rotate and 4 positions of tilt to position the desired character for printing. Upper case shift rotates the ball 180 degrees via a separate cam. Its been over 30 years since I worked on one, but in my early days as a service rep I worked on so many selectric terminals, the way they operate is permanently burned into my brain.
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RE: Oldest computer you've used for "real work"? - Paul Berger (Canada) - 03-10-2015 02:53 AM

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