In reply to Alan Fletcher's message of Wed, 31 May 2017 17:18:20 -0700: Hi,
It would have been a lot simpler to have just removed the enter key requirement from the program and operated it in a loop. >On Wed, 31 May 2017 18:04:23 -0400 >Jed Rothwell <[email protected]> wrote: > >> Data General and the early microcomputers had toggle switches and LED >> readouts of processor states. I never saw anyone use these controls, or read >> them for any purpose. > >My boss, Milt Meinck, back in the early seventies did! When designing the >chips for the first Singer electonic sewing machine. They had a very early >Calma graphics system (Serial #5 or so), based on a DG Nova. > >The needed to queue up a lot of plots overnight. But the system would pause, >waiting for the operator to press the "Enter" key to confirm the next plot. > >They realized that the LED lights would settle to a particular state. > >So they rigged a set of photodiodes over the lights, and a bit of logic >circuitry to recognise that light configuration and activate a solenoid which >depressed the "Enter" key. > >When we bought a Calma system years later, the specification included an >"Electronic finger" capability, for queing plots with no operator intervention. Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
