problems with tape drive

[Dana Holland]

I'm having problems accessing the tape drive on our Dell box.  We're 
running AS 4.  It's a Seagate DAT-72 SCSI drive.  It appears that the 
system is recognizing the drive during bootup, and that it's being 
assigned the name of st0.  But none of the "mt" commmands work - I get 
"device not found".  I've googled it, but can't seem to find any 
information on the next step to take.  Any ideas?