Sam Calvert ([log in to unmask]) wrote:
:      On our 928RX, running with MPE/iX 5.0, we have an HPC1503B DDS drive
:      on ldev 7 which has been configured for autoreply mode and a 7978 on
:      ldev 9 which is not configured for autoreply.
 
:      After loading either a DDS cartridge or 9-track tape, a console
:      message reports the volume which has been mounted and SHOWDEV reports
:      appropriate information.  If however the tape is manually ejected or
:      removed from the drive without being accessed, SHOWDEV still reports
:      the old VOLID and DEN which might be seen as indicating that the tape
:      is still available.
 
:      Any ideas on how to disable this 'feature' or suggestions on how to
:      remotely determine the actual status of a tape drive will be greatly
:      appreciated.
 
Back in ancient days when I worked with tape drives, the wizards at the
divisions that made the drives decreed (in their infinite wisdom) that
only on-line events caused host interrupts.  Off-line events did not.
 
If this is still the case, it explains why SHOWDEV doesn't change when
you remove the tape.  It doesn't know you did.
 
-Larry "supported serial disc in another life" Byler-