HP Compaq dx6100 Series Technical Reference Manual page 203

C.2.6 Scan Codes
The scan codes generated by the keyboard processor are determined by the mode the keyboard is
operating in.
Mode 1: In Mode 1 operation, the keyboard generates scan codes compatible with
8088-/8086-based systems. To enter Mode 1, the scan code translation function of the
keyboard controller must be disabled. Since translation is not performed, the scan codes
generated in Mode 1 are identical to the codes required by BIOS. Mode 1 is initiated by
sending command F0h with the 01h option byte. Applications can obtain system codes and
status information by using BIOS function INT 16h with AH=00h, 01h, and 02h.
Mode 2: Mode 2 is the default mode for keyboard operation. In this mode, the 8042 logic
translates the make codes from the keyboard processor into the codes required by the BIOS.
This mode was made necessary with the development of the Enhanced III keyboard, which
includes additional functions over earlier standard keyboards. Applications should use BIOS
function INT 16h, with AH=10h, 11h, and 12h for obtaining codes and status data. In Mode
2, the keyboard generates the Break code, a two-byte sequence that consists of a Make code
immediately preceded by F0h (i.e., Break code for 0Eh is "F0h 0Eh").
Mode 3: Mode 3 generates a different scan code set from Modes 1 and 2. Code translation
must be disabled since translation for this mode cannot be done.
NOTES:
Key
Pos. Legend Mode 1
1 Esc 01/81
2 F1 3B/BB
3 F2 3C/BC
4 F3 3D/BD
5 F4 3E/BE
6 F5 3F/BF
7 F6 40/C0
8 F7 41/C1
9 F8 42/C2
10 F9 43/C3
11 F10 44/C4
12 F11 57/D7
13 F12 58/D8
Technical Reference Guide
Table C-2.
Keyboard Scan Codes
Make/Break Codes (Hex)
Mode 2
76/F0 76
05/F0 05
06/F0 06
04/F0 04
0C/F0 0C
03/F0 03
0B/F0 0B
83/F0 83
0A/F0 0A
01/FO 01
09/F0 09
78/F0 78
07/F0 07
361834-001
Keyboard
Mode 3
08/na
07/na
0F/na
17/na
1F/na
27/na
2F/na
37/na
3F/na
47/na
4F/na
56/na
5E/na
C-11