DSD 4140 Qbus floppy controller

While searching through my collection of old Qbus cards I just discovered that I have a DSD 4140, which appears to be an RX02 compatible interface to Shugart SA800 or SA850 drives. The only documentation that I have is a small reference card which has the jumper configuration and a summary of the commands (from which it appears that the controller also supports formatting drives with a write sector command followed by a couple of magic values written to the data register). Does anyone have any more information / documentation for this controller? Since I don't have any 8" Shugart interface drives available I'm probably going to have to hook this thing up to a 5.25" or a 3.5" drive in order to try it out. I seem to recall that constructing a suitable 50 way to 34 way cable adaptor is relatively simple, but again I would appreciate references or more information from anyone who has done this kind of thing recently. Michael