M2488 PRODUCT GUIDE TAPE UNIT SCSI COMMANDS
April 1997 CG00000-011503 REV. A 4-25
4-3.7 LOAD UNLOAD command 1Bh
The LOAD UNLOAD command performs either a rewind operation or a rewind and unload opera-
tion. Prior to performing either of these operations, any buffered write data and buffered filemarks are
written to the tape. Also, prior to unloading a cartridge the Statistical Log Sense data is cleared.
4-3.7.1 LOAD UNLOAD CDB Description
LOAD UNLOAD is a six-byte command. The bytes are shown below and described in Table 4-
24. Common fields are described in paragraph 4-3.1 on page 4-4.
BITS
BYTES 7 6 5 4 3 2 1 0
00 0 0 1 1 0 1 1
1LUN Reserved Immed
2Reserved
3Reserved
4Reserved Reserved * Reten Load
5Reserved Flag Link
Note: Changeable fields in the CDB are shaded.
* This bit has an ANSI definition other than reserved; however the ANSI definition of the bit is not applicable for this
product. The bit is indicated as reserved since it should always be set to 0 for this product.
Table 4-24. LOAD UNLOAD Field Description
BYTE BIT VALUE DESCRIPTION
0 0-7 1Bh Operation code.
1 0 0 If Immed (Immediate) bit is 0, status is not returned for the LOAD
UNLOAD command until the load or unload operation has completed or
has failed.
1 If Immed is 1, Status is returned for the LOAD UNLOAD command as
soon as the CDB has been validated and any buffered write data and
filemarks have been written to tape. The load or unload operation has been
started but not necessarily completed when status is returned.
4 0 0 If Load is 0, rewind tape and unload tape cartridge.
1If Load is 1, rewind tape.
4 1 0 or 1 The Reten (retension) bit can be set to 0 or 1. The tape unit performs no
extra actions whether or not the bit is set.