On May 6, 19:25, Daniel A. Seagraves wrote: It's a QBus controller for SMD drives. It will support two physical drives, making them emulate two (or more, if necessary) logical DEC drives. We need to know the suffix (SC03/A, SC03/B, SC03/C) as there are at least three versions, emulating different drives. I have an SC03 which emulates RM03s, but there's an MSCP version as well. I've got the manual for this one, too. QBus communications controller of some sort. I don't know the details on this one, though. -- Pete Peter Turnbull Dept. of Computer Science University of York