KRQ50/RRD40 problems

I've got a KRQ50 (M7552) and a RRD40-DC (the 15 pin LMSI version, not the SCSI version!) drive in a MicroVAX-III, but I can't seem to get them working. VMS sees the KRQ50 as PUB0, but it doesn't see any drives on the controller. Any attempt to access DUB0 just gives device offline errors. I read somewhere that the KRB50 had to have a particular firmware version before it would work with the RRD40 - does anybody know the correct ROMs that I should have on my board? I didn't have a cable to connect the drive and controller, so I made one. Is the cable just supposed to be a DB15M <-> DB15F with all pins wired straight thru? Is there anything special about the cable? Is there any significance to the A and B ports on the KRQ50 (i.e. does it matter which one you use)? Unfortunately this seems to be a really rare device, and online docs are pretty much non-existent. Thanks, Bob Armstrong