4-8
Compaq DAT AutoLoader Reference Guide
Compaq Confidential – Need to Know Required
Writer: Debbie McRill Project: Compaq DAT AutoLoader Reference Guide Comments:
Part Number: 326817-003 File Name: e-ch4 Operation.doc Last Saved On: 12/20/99 2:35 PM
If the host sends an UNLOAD command (LOAD/UNLOAD with the LOAD
bit set to 0), the same procedure is completed, but the magazine is not ejected
at the end.
If you press the
Eject
button during the 30 seconds when the DAT
AutoLoader checks magazine positions following insertion of a magazine, the
magazine is ejected immediately, even if Medium Removal Prevention is in
force.
If the host has previously sent a PREVENT MEDIA REMOVAL command,
the unloading action is different in two ways:
■
The
Eject
button is disabled and has no effect. It does not initiate an
unload sequence.
■
An UNLOAD command puts the drive into a semi-loaded state. It takes
the drive offline and unthreads the tape, but does not eject it.
The effects of PREVENT MEDIA REMOVAL continue until an ENABLE
MEDIA REMOVAL command is received, or the drive is reset.
Forcing Cassette Ejection
CAUTION:
You can lose data if you force ejection of a tape. The tape may also
end up invalidly formatted because EOD (End of Data) may not have been
written. Force ejection only as a last resort to recover a cassette. Never use it as
a quick way of ejecting a cassette.
If you press the
Eject
button when the drive is busy, it may be a long time
before the drive responds to the request, because it is finishing the task it is
performing first. This method ensures that the task is terminated in a
controlled manner, and no data is lost.
However, if you need to unload a cassette urgently, even at the risk of losing
data, you must force ejection as follows:
1.
Hold the
Eject
button down for at least 5 seconds. The LCD displays
“Force Eject.”
2.
The DAT AutoLoader waits 35 seconds to give the normal ejection
procedure a chance to occur.
3.
Once this time has elapsed, if there is a tape loaded in the drive, it is
immediately unthreaded and the cassette is ejected, regardless of what
operation the drive was performing. The cassette is then returned to its
position in the magazine, and the drive is reset as though the power has
been cycled.
