Command Descriptor Block; Table 10-1: Load/Unload Command Descriptor Block - Tandberg Data SLR7-140 PROGRAMMER Manual

BYTE BIT 7
00 Operation Code 1Bh
01 Logical Unit Number (LUN)
02 RESERVED
03 RESERVED
04 RESERVED
05 Control Byte
Table 10-1:
IMM
RET
Load
EOT
Tandberg Data

10.2. Command Descriptor Block

6 5
LOAD/UNLOAD Command Descriptor Block
An Immediate (IMM) bit of zero indicates that the Drive
will not return status until the LOAD/UNLOAD operation
has completed. An IMM bit of one indicates that the
Drive will return status as soon as the execution of all
previous commands have been completed and the Command
Descriptor Block of the LOAD/UNLOAD command has been
validated.
A Retension (RET) bit of one indicates that the Drive
will perform a retension pass before the load or unload
operation is performed. Retension means moving the tape
one complete pass between EOT and BOT.
A Load bit of one indicates that the tape will be
logically loaded and moved to BOM. The tape is logically
loaded which means that the Drive is able to accept
medium access commands. A Load bit of zero indicates
that the tape is logically unloaded. The Drive will no
longer accept media access commands.
An End Of Tape (EOT) bit of zero indicates that the tape
will be positioned at BOM after the unload operation has
been performed. An EOT bit of one indicates that the
tape will be
operation has
retensioning of the cartridge next time it is used.
Combinations of the EOT, RET and Load bits are shown in
the table below:
EOT RET
0 0
0 0
0 1
0 1
1 0
1 0
1 1
1 1
Table 10-2:
10-2 Tandberg SLR Product Line SCSI Functional Specifications
4 3
RESERVED
positioned at EOT
been performed.
Load Operation Performed
0 Unload, move to BOM
1 Load, move to BOM
0 Retension, Unload, move to BOM
1 Retension, Load, move to BOM
0 Unload, move to EOT
1 Illegal, CHECK CONDITION
0 Retension, Unload, move to EOT
1 Illegal, CHECK CONDITION
LOAD/UNLOAD Operations
Load/Unload
2 1
IMM
EOT RET Load
after the unload
This allows
0
fast