Clicker assembly
Provided by the ASK Keyboard Dictionary
Also known as: keyboard clicker, keyboard solenoid, operator feedback, simply "solenoid"
A clicker assembly was an internal component known for being present in various Model B and some Model F terminal keyboards. It was typically a solenoid, but speaker-based implementations were also known. When enabled, it would generate considerable feedback whilst keys were being pressed. For IBM's terminal usage, it was used for indicating when the keyboard was enabled by its host terminal/program to its operator, and potentially for other audible cues depending on the exact terminal/terminal family. A typical example of its use for 327X-75 type and 327X-87 type Model Bs would be if the terminal's operator purposely enabled the clicker, it would engage during key presses and remain silent when the keyboard has been disabled by the host terminal/program. If the terminal operator purposely disabled the clicker, the opposite would be true and the clicker would only engage if said operator tried pressing keys whilst the keyboard is disabled by the host terminal/program. It has also been theorised that it was also used to generally enhance audible feedback, in some ways comparable to the sound pollution of a mechanical typewriter.
