yet another object (Unibus card?) to identify

[Pete Turnbull]

While sorting through some Unibus cards I've had on a dusty shelf for 
years, I came across a strange card (picture at 
https://www.flickr.com/photos/pnt103/17011635052/).

It has no maker's name, but what looks like a zigzag triple S logo near 
the centre of the top edge, and the legends "2010-60", "2010-6001 C835" 
and "EM PC" next to that.

Apart from 74LS series, it has the following noteworthy ICs:
   10 x Texas 74S2472 PROMs on left
   4 x 20-pin and 1 x 16-pin ICs look like PALs at lower right
   2 x 74LS181 (4-bit ALU) near the centre, with
     2 x AMD 27S03 (16x4-bit bipolar RAM) and 4 x AM2907 (quad bus xcvr)
   2 x white ceramic gold-top ICs 93L422-DC (256x4 static RAM)
   12.5MHz crystal
   2 x 7439 (marked "SEL"), 2 x DS8837, 5 x DS8641
   12 x 75452 (high current high speed dual-NAND peripheral drivers)
and a 50-pin 3M IDC connector and a 2x15-way edge connector on the top edge.

Any suggestions as to what it is or who made it?

Being a hex-height card but having only CDEF fingers, it's the exception 
that proves the rule that all Unibus hex cards have all six sets of 
contacts ;-)

-- 
Pete

Pete Turnbull