Vintage PC pages
Home -> Vintage PCs -> IBM 1391406 Keyboard

The IBM 1391406 Keyboard

Note: You need a browser capable of displaying SVG images to see the keyboard layouts.

The IBM 1391406 is the 102-key 'extended' keyboard originally shipped with PS/2 computers. If someone mentions an IBM Model M keyboard, this is usually the one they're talking about.

My particular model uses the UK layout and has a detachable 6-pin PS/2 plug.


When sent an identify command (0xF2), the keyboard returns the byte sequence 0xAB 0x83 (if translation is on, this comes out as 0xAB 0x41).


The keys on the 1391406 are laid out like this:

The keyboard supports all three IBM scancode sets. The scancodes it returns are:

Set 1


Set 1 is not intended to be translated by the keyboard controller. If you do turn translation on, you get these codes:


Set 2


These scancodes are expected to be translated by the keyboard controller, producing the same output that you'd get from (untranslated) Set 1:

Set 3

Set 3 uses the same position-based coding as the 122-key terminal keyboards and the 84-key AT keyboard. It is the only set to distinguish between the key position above Return (where Backslash is on a 101-key keyboard) and the one to the left of Return (where Hash is on a 102-key keyboard).


After translation by the keyboard controller, these codes become:

John Elliott 1 August 2009.