Info Catalog edt: GNU/Linux edt: Platform-specific notes

edt: Unix

 
 4.4 General Notes on Using <NumLock> for the <PF1> Key on Unix Systems
 ======================================================================
 
 Making the physical <NumLock> key available for use in the EDT Emulation
 requires some modification to the default X Window settings.  Since the
 keycode assignments vary from system to system, some investigation is
 needed to see how to do this on a particular system.
 
    You will need to look at the output generated by ‘xmodmap’ invoked
 with the "-pm" switch.  For example, on RedHat GNU/Linux 5.2 on a PC, we
 get the following output when running ‘xmodmap -pm’:
 
      xmodmap:  up to 2 keys per modifier, (keycodes in parentheses):
 
      shift       Shift_L (0x32),  Shift_R (0x3e)
      lock        Caps_Lock (0x42)
      control     Control_L (0x25),  Control_R (0x6d)
      mod1        Alt_L (0x40),  Alt_R (0x71)
      mod2        Num_Lock (0x4d)
      mod3
      mod4
      mod5        Scroll_Lock (0x4e)
 
 Note that Num_Lock is assigned to the modifier ‘mod2’.  This is what
 hides Num_Lock from being seen by Emacs.
 
    Now, ‘xmodmap -pke’ yields:
 
         .
         .
         .
      keycode  77 = Num_Lock Pointer_EnableKeys
         .
         .
         .
      keycode  96 = F12
         .
         .
         .
 
 So, in RedHat GNU/Linux 5.2 on a PC, Num_Lock generates keycode 77.  The
 following steps are taken:
 
   1. clear the assignment of Num_Lock to mod2;
   2. swap the keycodes assigned to F12 and Num_Lock;
   3. assign Num_Lock back to mod2.
 
 The ‘.xmodmaprc’ file looks like this:
 
      ! 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
 
    So, after executing ‘xmodmap .xmodmaprc’, a press of the physical
 <F12> key looks like a Num_Lock keypress to X.  Also, a press of the
 physical <NumLock> key looks like a press of the <F12> key to X.
 
    Now, ‘edt-mapper.el’ will see ‘f12’ when the physical <NumLock> key
 is pressed, allowing the <NumLock> key to be used as the EDT <PF1>
 (<GOLD>) key.
 

Info Catalog edt: GNU/Linux edt: Platform-specific notes