It's probably the SCSI layer. Do I implement TMSCP(sp?)
TMSCP is not SCSI. TMSCP is the tuned-for-tapes version of MSCP, DEC's
Mass Storage Control Protocol. MSCP is a protocol run between hosts and
disks; TMSCP is an adaptation of it designed for tapes.
Given the questions you were asking, I would say it is highly unlikely you
will need to implement TMSCP. The only cases I can see where you have a
need to implement TMSCP are (1) building an emulator of some sort, (2)
writing host code to speak to DEC tapes, or (3) building a glue layer, such
as a board that speaks TMSCP to the host and SCSI to a drive. It does not
strike me as likely that you would be taking on any of those while still
having occasion to ask what you were asking.
I wasn't asking if I should implement TMSCP, but rather whether my hardware
and firmware do. I have a hunch that booting from MUA0 is breaking because
of the SCSI board in the TKZ-50, but I can't be more specific and could
easily be wrong -- it's just a hunch.