Linux

Point value changed by question poster.

I'm not a SCO expert, but running the file command against the /dev entry for the tape device will often provide useful info on some Unix platforms.

Do you have tctl or mt commands, sending an mt rewind to the tape drive will either work, or give you an error if no tape is loaded....

I'm not familiar with SCO either, just Solaris, HP and AIX. If you have mt available that would be good to use, but you probably don't want to rewind the tape (if you plan to store more than one image on a tape the rewind command will put it back to the beginning and your next write will overwrite what was on the tape). Try this syntax -- mt -f /dev/rmt/0n status, assuming /dev/rmt/0 is the location of your tape. The n is for no rewind and status gives you a simple three line status of the tape. If there is no tape then you will get an error when you run this command instead of a three line status output.

Good luck.

now i'm running out of ideas :)
Have you tried http://www.seagate.com/support/tape/utils/inquire.html
or
http://www.unitrends.com/scsitc.html

On SCO systems the "tape" command replaces "mt". I use "tape status" in scripts and grep the output (silently) to check tape status. A while loop is good for this if you need to wait until a tape is loaded.