One handed UNIX, Emacs for disabled person?

[Dan_Jacobson at ATT.COM]

Hello.  Has anybody got ideas for using mainframe UNIX or computers in
general for a disabled person with use of only the right hand?  I am
thinking of recommending a terminal with two "control" keys (e.g., the
Teletype 4425) instead of the usual one.  [Turning to editors:] Also
making heavy use of GNU Emacs numerical keypad programmability, but
then again perhaps running it in VI emulation to avoid the old
control-key finger stretch.  [Also perhaps having a control key prefix
character, just like ESC means "Meta-" ...]  The mouse also seems
important.  Of course there's the possibility of just using plain VI,
however I have not met the person yet and am not yet aware of their
future customization needs.

[also posted to misc.handicap [hopefully]]
-- 
Dan_Jacobson at ATT.COM  Naperville IL USA  +1 708 979 6364