I'll add a little something. Since this topic is so open.
I took apart a VS90 a couple of years ago. It was passive
backplane, extremely wide (capacity 30 cards?) separate
data and control busses, multiprocessing '086 architecture.
Neat hidden blinkenlight conbtriool panel.
Will, didn't you get one of those CPU cards, couldit've
been 8086?
John A.
disclaimer: one or more errors possible above (I have a cold)