Hi!
> 
> Don't understand, my TK50 is not working.
> Only tar cannot use it. Can i find other archiver utility?
> 
> With "dd", i can use it, but the: "tar -cvf /dev/mt0 file.ext" is not
> working.

The TK50-driver in NetBSD is a little bit crazy. Perhaps try as -f
/dev/rmt0, or don't specify -f (and no device name). Hmm... Bad Idea. I
have only a FreeBSD/i386 Box over there and here the tar command says:

 --file [hostname:]file  Read or write the specified file (default is
                             /dev/rsa0)

Don't know if it is rmt at the VAX.
But from your /var/log/messages I would say it's a bug in the
NetBSD-TK50-Driver routines.

Regards,
	Freddy