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6.Command Specification
6.3. LOAD/UNLOAD 1Bh
Bit
7
Byte
0
1
2
3
4
5
The LOAD UNLOAD command requests that the drive enable or disable the media for further operations. This
command may also be used to request a retention function.
IMMED: If this bit is set, status is returned as soon as the load or unload operation is initiated. Otherwise, the status
is returned after the operation has completed.
LOAD: A LOAD bit of one and a HOLD bit of zero indicates the medium in the drive shall be loaded and positioned
to the beginning-of-partition zero. A LOAD bit of zero and a HOLD bit of zero indicates the medium in the drive shall
be positioned for removal at the extreme position along the medium specified by the EOT bit.
A LOAD bit of one and a HOLD bit of one indicates if the medium has not been moved into the logical unit, the
medium shall be moved in but not positioned for access. The EOT and RETEN bits shall be set to zero. Following
successful completion, the drive shall return GOOD STATUS. If both the medium and drive support MAM, the drive
shall generate a unit attention condition for all initiators with the additional sense code and additional sense code
qualifier set to MEDIUM AUXILIARY MEMORY ACCESSIBLE.
A LOAD bit of zero and a HOLD bit of one indicates if the medium is in the drive, the medium shall be unthreaded but
shall not be ejected. Following successful completion, the drive shall return GOOD STATUS. If both the medium and
drive support MAM, the drive shall generate a unit attention condition for all initiators with the additional sense code
and additional sense code qualifier set to MEDIUM AUXILIARY MEMORY ACCESSIBLE.
RETEN: A RETEN bit of one indicates that the drive unit shall perform a retention function on the current medium. A
RETEN bit of zero indicates that the drive shall not perform a retention function on the current medium.
EOT: An end-of-tape (EOT) bit of one and a Load bit of ZERO indicates that the medium shall be positioned at
end-of-medium for removal from the peripheral device. Prior to performing the unload operation, any buffered data
that is to be written shall be transferred to the medium. An EOT bit of ZERO and Load bit of ZERO indicates that the
medium shall positioned at beginning-of-medium for removal etc. This drive does not support this bit. EOT bit of one
shall cause the target to return CHECK CONDITION status. The sense key shall be set to ILLEGAL REQUEST and
the additional sense code shall be set to ILLEGAL FIELD IN CDB. This field is not supported. This field should be
set to 0.
HOLD: A HOLD bit of one indicates MAM shall be accessible upon completion of the command but the medium shall
not be positioned for access. A HOLD bit of zero and a LOAD bit of one indicates the medium shall be positioned for
access. A HOLD bit of zero and a LOAD bit of zero indicates MAM shall not be accessible upon completion of the
command.
If the drive has received an UNLOAD command with the Immediate bit set and then receives either another
command which would involve tape motion or TEST UNIT READY, the drive will return a CHECK CONDITION
status with a NOT READY sense key set.
6-8
6
5
4
Operation Code (1Bh)
Reserved
Reserved
3
2
Reserved
Reserved
HOLD
EOT (0)
Control
SONY AIT-4 drive SDX-900V series Ver.2.1
LOAD/UNLOAD
1
0
IMMED
RETEN
LOAD
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