That's still an electrical keyboard; it just has switches that click.<p>As I've mentioned previously, I restore pre-WWII Teletype machines, so I often type on real mechanical keyboards with electrical outputs. A Teletype keyboard is a motor-driven mechanism where, when you push a key, a clutch is released, a shaft revolves one turn, and, via levers and cams, contacts close and open and the bits are encoded and sent. During this time, which is about 200ms on the older machines, you cannot press another key - the keys won't move. You can't press two keys at once. Everything is mechanically interlocked. The best way to use one is to type at a steady 5 characters per second, like playing a piano.<p>Key travel is about half an inch, and the newer (1930 and later) models have spring-loaded green keytops with a nice cushioned spring mechanism. This provides about 0.100 inch of travel before the key lever starts to move. So if you type a little too fast, you don't blunt your fingers. The 1924 model doesn't have that; it has hard Underwood typewriter keys.<p>That huge key travel, combined with a low key pressure (the motor is doing all the work, unlike a manual typewriter) is rather relaxing. Teletype operators were expected to type with few errors; there is no way to backspace or correct. Full-time Western Union operators often typed "blind" on a machine with a keyboard and tape punch, but no printer or display. That's a lost art today.