* This specification are subject to be changed without notice.

EM83049

KEYBOARD ENCODER

6

5.2.1997

- Responds ACK.

- Clears output buffer.

- Sets all key type (affect only scan code set 3 operation).

F7 : Typematic

F8 : Make/Break

F9 : Make

FA : Typematic/Make/Break

- Returns to previous scanning rate.

Set Key Type ( Hex FB,FC,FD )

- Responds ACK.

- Clears output buffer.

- Receives key ID byte

- Responds ACK.

- Sets key ID type (affect only scan code set 3 operation).

FB : Typematic

FC : Make/Break

FD : Make

- Returns to previous scanning rate.

Resend ( Hex FE )

- Sends the previous output again. If the previous byte is RESEND, the last byte before RESEND shall be sent.

Reset ( Hex FF )

- Responds ACK.

- Checks clock and data lines - Reset in the high state for at least 500 microseconds or receives another command.

- Default to scan code set 2.

Command to the system

The following are the keyboard output commands.

Acknowledge ( Hex FA )

The keyboard sends an acknowledge in response to any valid command from the system except for RESEND

and ECHO.

BAT Completion Code ( Hex AA )

This command is issued after successful completion of keyboard self test.

Echo ( Hex EE )

The keyboard sends this code in response to an ECHO command.