Any ideas as to what it is, and if it can be made to do something
interesting?
--
Sounds like some variant of the 9817 / 9000/210
http://hpmuseum.net/display_item.php?hw=7
http://hpmuseum.net/display_item.php?hw=120
you'll find some field service manuals hiding under "Product Documentation"
there
googling 50960A turns up "200/SRM Server"
SRM is a 700kbit networking scheme which uses the 5096x DIO-I interfaces
So it was probably the server side box for an SRM network