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51 write same command (41h) – Quantum 10K II User Manual

Page 292

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SCSI Description

Quantum Atlas 10K II Ultra160/m SCSI Hard Disk Drives

5–225

5.51

WRITE SAME Command (41h)

The WRITE SAME command requests that the drive write the single sector of data
transferred by the initiator to the medium multiple times.

Bit

Byte

7

6

5

4

3

2

1

0

0

Operation Code (41h)

1

Reserved

PBdata

LBdta

RelAdr

2 - 5

Logical Block Address

6

Reserved

7 - 8

Number of Blocks

9

Control

Figure 5–111 WRITE SAME Command Descriptor Block — Data Format

Table 5–105 WRITE SAME Command — Field Descriptions

Field

Description

PBdata

Physical Block Data. – Not supported. This field must be zero.

LBdata

Logical Block Data. – A value of 1 requests that the drive replace the first
four bytes of the data to be written to the current logical sector with the
logical sector address of the sector currently being written.

RelAdr

Relative Address. – Not supported. This field must be zero.

Logical Block Address The address of the first logical sector where the Write operation will occur.

Number of Blocks

This field contains the number of contiguous logical blocks that are to be
written. A value of 0 requests that all the remaining logical blocks on the
medium are to be written.