News for hackers. Stuff that matters.

A comment on Raster CRT Typography According to DEC. Parent comment

Re:Raster CRT Typography According to DEC by ch_123 on Saturday March 30, 2019 @04:03PM (#19531470)
The solenoid on the one which I have (a 3278 keyboard) is separate to the keys. It is true that the solenoid will not operate when the terminal is unable to accept any key press, but it does not impede the operation of the keys themselves.

To the best of my knowledge, the only IBM keyboards that could flat out prevent the keys from being pressed were ones based on the Selectric typewriter mechanism, such as the 2741

[ Parent | on HN ]
Re:Raster CRT Typography According to DEC by kps on Saturday March 30, 2019 @08:00PM (#19532784)
In order to prevent two keys being active simultaneously, the Selectric had a linear track full of steel balls running from side to side, with just enough free space to allow a metal tab from a single key to enter. So locking the keyboard was just a matter of having a solenoid occupy the free space.
[ Parent | on HN ]