[NCLUG] obscure(?) xmodmap question

[Alan Silverstein]

Gang, does anyone here know why xmodmap treats "Return" in the Shift
position as ESC-OM?

I'm now typing from a new RH4 system at work, but finding an annoying
problem trying to use it.  If I happen to have SHIFT down while pressing
ENTER, instead of a newline, I get ESC-OM.  This is true even if I do
this:

  /usr/X11R6/bin/xmodmap -e 'keycode 36 = Return Return Return Return Return Return'

Or even try this:

  /usr/X11R6/bin/xmodmap -e 'keycode 36 = Return KP_Enter Return Return Return Return'

But the keypad ENTER key does DOES yield a newline, even when shifted.

If I do this:

  /usr/X11R6/bin/xmodmap -e 'keycode 36 = Return exclam Return Return Return Return'

Then shift-ENTER does give me "!", so it's not completely broken.

And if I do this:

  /usr/X11R6/bin/xmodmap -e 'keycode 10 = 0x0031 Return'

Then shift-1 gives me (you guessed it) ESC-OM.

It appears that Return in the Shift position gets translated no matter
what I do, even if I map the shift-ENTER key to KP_Enter.

This is mystifying, doubly so trying to make sense of the xmodmap manual
entry, which isn't bad, it just isn't very good either.  I'm sure it all
makes sense once you understand keysyms, modifiers, pointers, etc.  And I
can't find anything on the Web to explain it either...

Thanks,
Alan Silverstein