6.Command Specification
LOAD/UNLOAD
6-8
SONY AIT-5 drive SDX-1100V series Ver.1.0
6.3.
LOAD/UNLOAD 1Bh
Bit
Byte
7 6 5 4 3 2 1 0
0
Operation Code (1Bh)
1
Reserved IMMED
2
Reserved
3
Reserved
4
Reserved HOLD
EOT
(0)
RETEN LOAD
5
Control
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 retension 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 will 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 will
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 will be moved in but not positioned for access. The EOT and RETEN bits will be set to zero. Following
successful completion, the drive will return GOOD STATUS. If both the medium and drive support MAM, the drive
will generate a unit attention condition for all initiators with the ASC and ASCQ 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 will be unthreaded
but will not be ejected. Following successful completion, the drive will return GOOD STATUS. If both the medium
and drive support MAM, the drive will generate a unit attention condition for all initiators with the ASC and ASCQ
set to MEDIUM AUXILIARY MEMORY ACCESSIBLE.
RETEN:
A RETEN bit of one indicates that the drive unit will perform a retension function on the current medium.
A RETEN bit of zero indicates that the drive will not perform a retension function on the current medium.
EOT:
An end-of-tape (EOT) bit of one and a Load bit of ZERO indicates that the medium will 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 will be transferred to the medium. An EOT bit of ZERO and Load bit of ZERO indicates that the
medium will be positioned at beginning-of-medium for removal etc. This drive does not support this bit. EOT bit of
one will cause the target to return CHECK CONDITION status. The sense key will be set to ILLEGAL REQUEST
and the ASC will be set to ILLEGAL FIELD IN CDB. This field is not supported. This field will be set to 0.
HOLD:
A HOLD bit of one indicates MAM will be accessible upon completion of the command but the medium will
not be positioned for access. A HOLD bit of zero and a LOAD bit of one indicates the medium will be positioned for
access. A HOLD bit of zero and a LOAD bit of zero indicates MAM will 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.
