Help with SCSI tape on PDP-11 with RT-11

From: Jerome Fine <jhfine_at_idirect.com>
Date: Sat Jul 10 23:56:27 1999

Well, I need some help with a SCSI tape drive!!

ENVIRONMENT:
Hardware: CQD 220/TM set both ways for W3-6
                                          W2 is out, standard CSR
                                          for tape
                  TZK12-AA with jumpers OOOOOCCOOC
                                          = Parity, SCSI ID =4, TPWR
                                          (at least the SCSI ID seems to be 4
                                          since that is what the CQD 220/TM
                                          says to use for MU0: and MU0: exists)
                  DC 6250
Software: RT-11 V5.6

Symptoms:

I can do both an INIT MU0:
and a RUN BUP MU0:/Z
followed by: DIR MU0: for the simple INIT
                           BACKUP/DIR MU0: for the RUN BUP MU0:/Z
and for either DUMP/TERM MU0:
I get the correct stuff (which is somewhat different)
in each case, so I know I am writing to the tape drive
which stops and starts and rewinds, etc. the appropriate
number of times for these successful operations.

At first I had a SCSI hard drive on the 50 pin cable as
well (not at end of daisy chain - i.e. in the middle)
which made no difference to MU0: and the SCSI
hard drive works just fine at 160334 with or without
the tape drive powered on or off.

BUT, when I try to do a COPY DU0:a.b MU0:a.b
the system hangs without having written anything to MU0:
When I try to do a BACKUP DU0:a.b MU0:a.b
I get 2 error messages saying it couldn't do the BACKUP
and quits, again without writing anything to MU0:

Note that when I substitute a TQ50/TK50, everything
is OK with respect to PIP and BUP.

Please, any suggestions would be helpful.

Sincerely yours,

Jerome Fine
Received on Sat Jul 10 1999 - 23:56:27 BST