A keyboard controller is a chip on a computer’s motherboard that communicates with the keyboard. Within the keyboard, an encoder chip detects keypresses and reports them to the computer. Within the computer, the controller chip receives this information, and performs other tasks such as updating the LED status. The computer communicates with the keyboard via the keyboard controller. For PS/2 computers, the keyboard controller may also handle all communication with the mouse; prior to PS/2, the mouse connection used different protocols.
A keyboard controller was historically a standard component of an IBM PC motherboard (an Intel 8042 chip, part of their MCS-48 family of microcontrollers), and likewise it was found in IBM-compatible computers. With the complete adoption of USB for peripheral connections, modern computers do not need this component.
Exactly which makes, models and eras of computers used such a chip remains to be determined.
Manufacturers and vendors of keyboard controller chips include:
- "8042" PS/2 Controller — OSDev Wiki