I seem to
recall that HP used a D-shell connector with only three
larger round pins for video on some of their stuff (possibly DE
sized, but I have a feeling it might be slightly larger).
3W3, I forgot about that. I have an Alpha (from the days when DEC was
still DEC) that has 3W3 video. It's a DA-size shell.
Not just DEC. IBM uses it too.
Peace... Sridhar