4.3 PC Users Running GNU/Linux

The default X server configuration varies from distribution to distribution and release to release of GNU/Linux. If your system fails to recognize the keypad keys as distinct keys, change the NumLock state, turning it on or off, as the case may be, then try again. If this doesn’t solve your problem, you may have to modify the X keysym mappings with xmodmap.

On one distribution on an Intel PC, the following .xmodmaprc set things up nicely.

! File:  .xmodmaprc
! Set up PC keypad under GNU/Linux for the Emacs EDT Emulation
clear  mod2
keycode  77 = F12
keycode  96 = Num_Lock Pointer_EnableKeys
add mod2 = Num_Lock

In this example, after feeding the file to the xmodmap command, the PC NumLock keypad key will be configurable for the emulation of the PF1 key. The PC keypad can now emulate an LK-201 keypad (less the comma key), the standard keyboard supplied with DEC terminals VT-200 and above. This .xmodmaprc file switches the role of the F12 and NumLock keys. It has been tested on Red Hat GNU/Linux 5.2. Other versions of GNU/Linux may require different keycodes. (General Notes on Using NumLock for the PF1 Key on Unix Systems for further help on how to do this.)

Please note: Remember, it may be necessary to have NumLock in one position (ON) or the other (OFF) for the PC keypad to emulate the LK-201 keypad properly.