Sony SDX-1100V/R Computer Drive User Manual


 
6.Command Specification PREVENT ALLOW MEDIUM REMOVAL
6-62 SONY AIT-5 drive SDX-1100V series Ver.1.0
6.11. PREVENT ALLOW MEDIUM REMOVAL 1Eh
Bit
Byte
7 6 5 4 3 2 1 0
0 Operation Code (1Eh)
1 Reserved
2 Reserved
3 Reserved
4 Reserved Prevent
5 Control
The PREVENT ALLOW MEDIUM REMOVAL command requests that the target enable or disable the removal of
the medium in the drive. This mechanism is independent of device reservations and the drive will not allow
medium removal if any initiator currently has medium removal prevented.
The prevention of medium removal will begin when any initiator issues a PREVENT ALLOW MEDIUM REMOVAL
command with a prevent bit of one (medium removal prevented). The prevention of medium removal for the logical
unit will terminate:
1. Upon a hard RESET condition.
2. Upon the receipt of a BUS DEVICE RESET message from any initiator
3. After all initiators that have medium removal prevented issue PREVENT ALLOW MEDIUM REMOVAL
commands with a prevent bit of ZERO, and the target has successfully performed a synchronize cache
operation.
While a prevention of medium removal condition is in effect the target will inhibit mechanisms that normally allow
removal of the medium by an operator.
Prevent: When this bit is set, the drive will not eject the tape following an UNLOAD. When it receives the
UNLOAD, the drive writes any buffered data to tape, rewind, then unthreads the tape from the mechanism. The
drive does not eject the tape. Setting this bit also completely disables the Eject button on the front panel (except
emergency eject). This situation remains until the Prevent bit is set to ZERO.
When this bit is set to ZERO, the drive ejects the cassette following completion of an UNLOAD. The Eject button is
also re-enabled.