My Alt keys don't work!

[Sean Hammond <seanhammond@lavabit.com>]

Could someone help me sort out my keyboard configuration, or send me on 
the right track? I've investigated a little but I really don't know what 
to do. It's a somewhat tricky configuration.

1. I have two keyboards. The built-in one (it's a laptop), and an 
external one that I use. Since the keyboards are different no one 
configuration will work for both. Is it possible to have different 
configs for different keyboards?

2. Since the built-in keyboard has a stuck left alt key (it presses 
itself all the time) I had to disable left alt using an Xmodmap file. 
But this also disables left alt on the external keyboard. Is there a way 
to disable the key on the built-in only?

3. Currently I've tried to get my single keyboard config working for the 
external keyboard, but there are problems. Details follow. I apologise 
for the length of this but, well, it's complicated and I wanted to give 
as many relevant details as I could.

I'm running Debian testing on an OLPC XO-1 via DebXO, a build of Debian 
for the XO-1. The XO-1 has a slightly unusual keyboard ofcourse, but the 
DebXO image comes with a usable configuration for it. My keyboard has 
the 'stuck alt key' problem where the left alt presses itself all the 
time making the XO unusable, so I used an Xmodmap file to disable left 
alt and turn the XO's left 'grab' key into an alt instead:

    remove mod1 = Alt_L
    keycode 64 =
    keycode 115 = Alt_L Meta_L
    add mod1 = Alt_L

This worked. Now I actually use the laptop with an external keyboard, 
currently a UK-layout IBM Model M. I just plugged this keyboard in 
(using a USB-PS2 adapter) and it worked, aside from various details of 
course. The layout was wrong, so I had to press " to get an @ and so on, 
and of course the Xmodmap unnecessarily disabled the left alt on the 
external keyboard as well, although Alt Gr seemed to function as an alt 
key.

When I upgraded from debian stable to testing it asked me various 
questions about my keyboard configuration and the end result was the Alt 
Gr on the external keyboard stopped functioning as well, and now I have 
no alt keys!

I went into the Gnome keyboard prefs and set the keyboard to 'Generic 
102 key (Intl) PC', I could not find IBM Model M in the list of 
keyboards so I chose this generic one after counting the number of keys 
(102). I set the layout to UK. Now all the keys seem to work, they do 
what is shown on the keys themselves, except:

*   Neither Alt key functions. I used the program xev to find that 
    Alt on the external keyboard is keycode 64 and Alt Gr is 108. 
    Obviously my Xmodmap file is still disabling keycode 64. In the 
    Gnome keyboard shortcuts config tool Alt is recognised as "0x40" and 
    not seen as a modifier key, Alt Gr is not recognised at all. I tried 
    to use Xmodmap to remap Alt Gr to an alt instead of remapping the 
    XO's 'grab' key as before: `keycode 108 = Alt_L Meta_L` but this 
    doesn't work (Alt Gr still does nothing), so I changed my Xmodmap 
    back to as before.

*   There is a key in the top-left under Esc which has three labelled 
    functions and I can't use the third one (the pipe character). Maybe 
    cause you have to press Alt to get the third one?
  
*   There is a key near the bottom-left which is broken pipe and backslash, 
    this key doesn't function at all.

So all in all I can't use Alt, pipe or backslash, which makes things 
fairly difficult, and I'm out of ideas.

Thanks in advance for any pointers.