I used to have an IBM M-5 keyboard and used the Alt_R key as the
compose key. When I switched to a Dell Quiet Key keyboard compose
ceased to work.

I find that

  $ nano /etc/default/keyboard
    XKBMODEL="pc105"
    XKBLAYOUT="us"
    XKBVARIANT=""
    XKBOPTIONS="compose:ralt"
    BACKSPACE="guess"

I copied the currrent keyboard map to my home direcory:

$ xmodmap -pke > ~/.Xmodmap

When I go to edit it to define a compose key, they map lacks the
key I need:

  $ xmodmap -pke | grep Alt
    keycode  64 = Alt_L Meta_L Alt_L Meta_L

but no Alt_R or ralt. I could use right Windows but do not see it
in the map either.

Should not both keys be present in a pc105 keyboard regardless of who
made it?

Or must I dispose of the Dell keyboard?

--

     Haines Brown