With IBM compatible computers, the keyboard controller or Intel 8042 keyboard controller is found on the motherboard. The controller handles input received from the computer keyboard, A20 lines, reset, deciphering scan codes, and the PS/2 mouse. With later models of keyboards the 8042 was replaced with the 8742 microcontroller, which had a microprocessor, RAM, and I/O ports.

Keyboard terms, Scan code

  • How to fix A20 error.
  • Keyboard help and support.