3B2 install tape woes (or: Wangtek 5125ES docs/jumper info)

[Josh Dersch]

Hi all--

Had a random desire to get my 3B2/600G running again over the weekend 
(this machine was the first computer I ever used UNIX on, for better or 
for worse...) after finding a working 300MB CDC Wren SCSI drive for it.  
(The UNIX install media for this machine only supports a very limited 
selection of drives -- it's possible to get the machine booting from an 
unsupported drive, but it requires having a running UNIX on a supported 
drive first, as far as I know.)

Unfortunately, disaster struck halfway through the installation -- the 
tape drive's roller turned to mush.  I checked it out before running the 
install and it seemed fine -- it was a solid rubber wheel -- but I guess 
something about actually running it caused it to break down.  I managed 
to fix the roller, but the tape got goo all over it and despite my best 
efforts at cleaning it, that section of tape is unreadable so I can't 
reinstall.

Fortunately, I have backups of the UNIX install tape files on my PC 
(several versions thereof, in fact)-- so you'd think it'd be a simple 
matter of attaching the tape drive to the PC and dd'ing over the 
files... but I'm not having any luck on any of the machines I've tried.  
I can only manage to copy over one file; attempting to write subsequent 
files fails.  I have a failing drive w/a partial UNIX install for the 
3b2 that boots about half the time, so I tried to do the same from the 
3B2 w/this drive installed and it has the same problem writing >1 file, 
so it looks to be an issue with the drive and not the controller/OS.

The drive is a Wangtek 5125ES, a 125MB (or 120MB, if you believe AT&Ts 
docs) drive.  The error I get on from my Linux PC:

dd: writing /dev/nst0: Input/output error
st0: Current: sense key: Medium error
    Additional sense: Filemark detected
Info fld=0x1
st0: Error on write filemark

(I've of course tried different tapes, with the same result.)

This is of course the only drive I have that's capable of writing tapes 
in this format, and of course the 3B2 isn't happy with any other tape 
drive I have... Anyone have any jumper settings for this drive?  Anyone 
experienced this problem?

Thanks,
Josh