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Chapter 4 SCSI Commands
READ Command (08h)
DLT-S4 Interface Reference Guide
233
Table 128
PREVENT /
ALLOW MEDIUM REMOVAL
Command Descriptor Block —
Field Descriptions
READ Command (08h)
4
The
READ
command transfers one or more data blocks from the medium
to the initiator starting with the next block on the tape.
Figure 117
READ
Command
Descriptor Block — Data
Format
Field
Value
Description
Preven
t
0
Clears the Prevent state corresponding to the initiator. When all initiators have
cleared their Prevent states, the Eject button and
UNLOAD
commands are enabled
both for the drive and for any attached tape automation system, library, or loader.
By default after power-on or a logical unit reset, the
PREVENT MEDIUM REMOVAL
function is cleared.
1
Effectively disables the Eject button on the drive’s front panel or a
LOAD UNLOAD
command from unloading the medium. If the drive is in a tape automation system,
any
MOVE MEDIUM
command is prevented from removing a data cartridge.
Bit
7
6
5
4
3
2
1
0
Byte
0
Operation Code (08h)
1
Reserved
SILI
Fixed
2 — 4
(MSB)
Transfer Length
(LSB)