Overnumpad
Provided by the ASK Keyboard Dictionary
Aka/also known as: pressure-based controller
"Overnumpad" is a nickname for a style of controller card used by fourth-generation Model Ms that is pressure-fitted to the host keyboard's membrane assembly. Compared to older Model M controller cards that used Triomate sockets to accept membrane flex cables, "overnumpad" style controller cards are smaller, electrically simpler and typically have lock-light LEDs onboard instead of having them on a separate PCB.
