Using SYSDIAG I have a job stream that I use to put a DDS tape back on line:
 
!JOB,OPERATOR.SYS;INPRI=8;OUTCLASS=LP,1;PRI=CS
!SYSDIAG
SCSIDDS LD 7 SC 50
LOADTAPE
0
E
E
!EOJ
 
 
If you replace the LOADTAPE with UNLOADTAPE it should eject it.
 
>
>HP-supplied utility that will call HPDEVCONTROL, or do I have to write my own?
Gary Jackson
Nevada CSOS
(916) 478-6407 - voice
(916) 478-6410 - fax