HP Vectra Technical Reference Manual page 200

Table 5.22
8041 to 5TO-8105 5cancodes and Commands
Codel
Command Description
OOH
OVERRUN. This code indicates that the 16 character keyboard buffer has
overflowed.
01
H-77H
Keyboard Scancodes. These represent the keys on the 81 H-OF7H keyboard.
The scancodes are listed in table 5.4.
OAAH
The 8041 Controller will report this byte when it completes the 8041
Controller's Self Test. This test is executed at Power on and after receiving
the Keyboard Command OFFH, Reset. Note: any other byte reported at
these times indicates failure.
OEEH
ECHO: this code is sent in response to the keyboard ECHO_COMMAND
command, OEEH.
OFOH Break Prefix code. This code is sent to indicate a key break. This code is
followed by the scancode of the key being released. This code will be sent
only in the AT scancode set mode.
OFAH ACK. this code is sent to acknowledge receipt of a command (except Echo
and Resend).
OFDH Diagnostic Failure. This code is sent if a keyboard failure is detected.
OFEH Resend. This code is sent if the keyboard receives an invalid command or
detects an error in the transmission.
5.4.4 8041 to Logical Keyboard Driver Communication
The 8041 acts as an intelligent bi-directional buffer between the logical keyboard driver (Input
System) and the INT 09H driver and system software. The INT 09H driver and system software
communicate with the 8041 via the command and data ports (1/0 addresses 64H and 60H
respectively). The 8041 has two additional ports which are used to communicate with the logical
keyboard driver.
The output port 068H is used by the logical keyboard driver to transfer data and commands to
the 8041 without overlapping with the industry standard keyboard commands. Data such as
keyboard scancodes and commands are transmitted in this manner. The HP specific commands
are listed in table 5.23.
Keyboard 191