On January 10, you wrote:
> How are your drives connected? Note that you must have a extra
> black cable between the disk and the controller, otherwise it won't
> work at all. I'll try to show it graphically:

  SUCCESS!!!

  My RA90 drives came from an SA600 disk array, and as such are bare
drives.  The bulkhead connectors are still in the rack, which is not
here.  I was connecting the cable from the controller distribution
panel directly to its identical mating connector on the back of the
drive, which would have worked fine if DEC hadn't stopped making sense
about ten years ago.  Well, they did, so it didn't.

  I have an Emulex SM80 controller here, which is a rackmount box with
SDI connectors on one side and SMD connectors on the other.  It has
little jumper cables on it, with big SDI bulkhead connectors similar
to that of the SA600 disk array.  I yanked one out of the SM80
assembly, plugged my SDI cable into it, and plugged it into the
drive.  Viola!  The ka640 saw it, NetBSD booted from an RD54 as dub0
saw it, and I'm currently copying files onto the darned thing.

  Thanks very much to all who offered helpful suggestions on this; in
this process I have learned a great deal about the kda50 and SDI in
general, with which I hadn't worked before.

                         Best regards,
                          -Dave McGuire