Chapter 4 SCSI Commands
LOCATE Command (2Bh)
DLT-S4 Interface Reference Guide
56
LOCATE Command (2Bh)
4
The
LOCATE
command performs high-speed positioning to a specified
block address. Use the
READ POSITION
command to obtain the block
address associated with the current position on tape. Then use the
LOCATE
command to position the tape at the same logical position for
high-performance restore operations of particular blocks of data.
Figure 21
LOCATE
Command
Descriptor Block
—
Data
Format
Table 32
LOCATE
Command
Descriptor Block
—
Field
Descriptions
Bit
Byte
7
6
5
4
3
2
1
0
0
Operation Code (2Bh)
1
Reserved
BT
CP
Immed
2
Reserved
3 — 6
(MSB)
Logical Object Identifier
(LSB)
7
Reserved
8
Partition
9
Control
Field
Description
BT
Block Type. The drive ignores this bit.
CP
Change Partition. Must set to 0.
Immed
Immediate. When set to 1, the drive returns status as soon as the operation
starts. When set to 0, the drive returns status after the operation has completed.
Logical Object Identifier Specifies the Logical Object Identifier to which the drive positions the medium.
Partition
Not applicable; the drive ignores this bit (see CP field).