I have a Tandberg 3800 QIC-525 tapd drive hooked to a 486 box 
running 1.3. I ran 'mt status'  and this is what I got:

st0: cannot set selected mode
SCSI tape drive, residual=0
ds=0
er=0
blocksize: 512 (512, 0, 0, 0)
density: 0 (0, 17, 16, 15)

	Then the kernel reports:

st0(ncr0:4:0): Check Condition on opcode 0x15
SENSE KEY: Illegal Request
COMMAND INFO: 524288 (0x80000)
ASC/ASCQ: Illegal Field in CDB
FRU CODE: 0x2
st0: cannot set selected mode.

What must I tell mt to select a valid mode? Termination and cabling are OK.

P.S.A