On Fri, 15 Jun 2001, NetBSD Bob wrote:

> > I don't know how to get around the retension, but you could probably use
> > the following to erase the tape.
> >
> >   dd if=/dev/zero of=/dev/rmt0 bs=64k
> >
> > I don't know if 64k is the optimal block size or not, but I read a message
> > a few days ago on the list suggesting 64k as a good read size for the
> > TK50.
>
> I will make a note of that.  I ate another TK50 cartridge, again,
> last night, because it stuck.  That retensioning is getting to be
> important.  The tape unrolled itself all over the inside of the
> BA123 case.

Maybe you've already done this, but I'm sure I've read on this list that
is (or are) some optical sensors in the TK50 which tend to get covered in
dust over time.  I don't have a manual, nor a tape drive to look at right
now.  You might take a look at opening and cleaning any dust out of the
drive to see if it'll behave better.

In this case, I'm just not sure that retensioning the tape would solve
your problem.  I'd also be kind of wary about erasing all your tapes
before writing to them.  Given that most of the TK50 media anyone will
come across this days is fairly old, you'll likely end up wearing out
tapes faster and depositing more metal oxide on the TK50 drive's tape
head than necessary.

You didn't happen to cut your teeth with tape drives on something like
one of the PC based Colorado 250 cartridge drives did you?

-brian.