Phil Storrs PC Hardware book

The Auxiliary byte values for the Special Key combinations

Key/s pressed Aux byte Key/s pressed Aux byte Key/s pressed Aux byte
Shift Tab 0F Alt Q 10 Alt W 11
Alt E 12 Alt R 13 Alt T 14
Alt Y 15 Alt U 16 Alt I 17
Alt O 18 Alt P 19 Alt A 1E
Alt S 1F Alt D 20 Alt F 21
Alt G 22 Alt H 23 Alt J 24
Alt K 25 Alt L 26 Alt Z 2C
Alt X 2D Alt C 2E Alt V 2F
Alt B 30 Alt N 31 Alt M 32
F1 3B F2 3C F3 3D
F4 3E F5 3F F6 40
F7 41 F8 42 F9 43
F10 44 Home 47 Up Arrow 48
Page Up 49 Left Arrow 4B Right Arrow 4D
End 4F Down Arrow 50 Page Down 51
Insert 52 Delete 53 Shift F1 54
Shift F2 55 Shift F3 56 Shift F4 57
Shift F5 58 Shift F6 59 Shift F7 5A
Shift F8 5B Shift F9 5C Shift F10 5D
Ctrl F1 5E Ctrl F2 5F Ctrl F3 60
Ctrl F4 61 Ctrl F5 62 Ctrl F6 63
Ctrl F7 64 Ctrl F8 65 Ctrl F9 66
Ctrl F10 67 Alt F1 68 Alt F2 69
Alt F3 6A Alt F4 6B Alt F5 6C
Alt F6 6D Alt F7 6E Alt F8 6F
Alt F9 70 Alt F10 71 Ctrl Prnt Scrn 72
Ctrl Left Arrow 73 Ctrl Right Arrow 74 Ctrl End 75
Ctrl Page Down 76 Ctrl Home 77 Alt 1 78
Alt 2 79 Alt 3 7A Alt 4 7B
Alt 5 7C Alt 6 7D Alt 7 7E
Alt 8 7F Alt 9 80 Alt 0 81
Alt hyphen 82 Alt = 83 Ctrl Page Up 84

When we press a Normal Key (the ASCII Keys) the data stored in the Buffer by the Keyboard Service Routine, has the ASCII code for that key as the first byte, and the Scan Code of the key that produced that ASCII code, as the second byte.

When a Special Key, or Special Key Combination is pressed, the first byte (the Main Byte) is always 00 to indicate a Special Key, and the second byte (Auxiliary Byte) is the value given in the above table.

All byte values in this table are given in Hexadecimal.

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