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Re: KA410 Boot Failure With TKZ-50



On 2020-06-14 00:29, Josh Moyer wrote:
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.

The SCSI controller in a uVAX 2000 is just talking plain SCSI. It does not do anything TMSCP like. But if it did, then it would just be a question of the boot code talking TMSCP, and you would be good.

If you had a tape drive talking SCSI, and the computer talked TMSCP, nothing would work at all. It would be a totally pointless setup.

Which is also why the TK50 is a TKZ-50. That "Z" hints that this is a SCSI variant. Admittedly it's SCSI implementation reputedly was a bit odd, but it's still SCSI.

  Johnny

--
Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt%softjar.se@localhost             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol


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