What about the program ONLINE by Stan Sieler?  We have found it
to be very reliable letting us know if a tape is mounted and if
it is online.

Documentation from program:

ONLINE  92A   Copyright (c) 1991  Allegro Consultants, Inc.
Written by Stan Sieler

ONLINE is a non-privileged program that tries to put most tapes
and DDS (DAT) cassettes "on-line" again.

Usage:
   run online;info="ldev"
or:
   run online;parm=ldev

For more help information, do:
   run online, help

Examples:        (assuming program is ONLINE.PUB.SYS)
                 (and assuming ldev 7 is a tape drive (or DDS)
                  with a tape (or cassette) mounted, but off-line)
<snip>

Regards,

Sam

Stan Sieler wrote:
>
> Frank writes:
>
> > or, from posix, you can
> >
> > tape status {/dev/Stp0}
>
> I can't:
>
>    /SIELER/HFS: tape status {/dev/Stp0}
>    tape: not found
>
> I.e., there doesn't appear to be a program called "tape" on our 6.0 system.
>
> Even if there is, I'd be surprised to find that it properly detects
> if a tape is in the drive!
>
> Bottom line: AFAIK, there's only *ONE* way to determine if a tape
> is in the drive *RELIABLY*:  look at it.
>
> The next best thing is the SYSDIAG/SCSIDDS solution.
>
> The least accurate approach is the :SHOWDEV solution.
> (Why?  Because if the tape was online and someone manually
> ejects it, it will continue to show as online.  A DOWN/UP command
> pair may cause it to no longer show as online.)
>
> --
> Stan Sieler                                          [log in to unmask]
>                                      http://www.allegro.com/sieler.html