Wangtek Cart tape

[hbo at nobbs.ucsb.edu]

I have a Wangtek 1/4" cartridge tape drive, model 5150ES which I'm trying
to make work on my Sun 4/110 - Sun OS 4.0.1. The drive reads QIC-24
formatted tapes successfully, though we do get some read errors, but fails
12 feet into a dump writing (presumably) QIC-150. My question is: does
SunOS 4.0.1 support writing QIC-150 format? Does any of this ring a bell
with anyone?  Following are the relevant commands and error messages:

The read error:

%tar tf /dev/nrst8
/foo ...
 .
 . (etc. successful reads are taking place)
 .
tar: tape read error: I/O error

The write error:

#dump 0csdtf 590 1200 18 /dev/nrst8 /dev/rsd0a
DUMP: Tape write error 87 feet into tape 1

The dump paramaters above were suggested by Sun. the number of feet before
the error occurs varies considerably from run to run.

Please reply via electronic mail. Thanks very much for any help you can
offer.