> They show a VAX-11/780 with RP06 and TU70 (I
think) and claim its
 > doing the graphics. But I'm curious, what terminal and software is
 > used? Does anyone have a clue? 
  You never really see a closeup of the terminal or any
explanation of how
 the image is being displayed, so its hard to say exactly. 
If you look closely there's a text terminal of some sort, green screen
with the menu, and the graphic display.  The keyboard for the text
terminal looks fairly VT-100ish, though the screen itself doesn't look
quite right to me.  (It is hard to see, so ymmv.)
At a guess, there are two serial lines -- vt100ish terminal, tablet --
and a video link from a graphics card (maybe a VT-30?) in the VAX to the
work area.
Perhaps someone should contact the poster of the video to see if they
have a higher resolution copy which could be studied without the
$deityawful youtube compression.
De