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Space 11h, Space 11h 148, Pre-execution checks – HP C737990900 User Manual

Page 148: Command descriptor block: cdb fields

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148 Commands

SPACE 11h

S

PACE

provides a variety of positioning functions that are determined by Code

and Count fields in the Command Descriptor Block. Both forward (towards

EOM) and reverse (towards BOM) positioning are provided.
Any unwritten data in the buffer is flushed to tape before the space is started.

The logical media position is then modified according to the Code and Count

fields. Once the space has started, it will complete even if the SCSI operation is

aborted for some reason (for example, the host selects and sends an abort

message).

Pre-Execution Checks:

The Code field must be 0, 1 or 3. If it is not then

CHECK CONDITION

status is

reported. Sense data will be as described in the Illegal Field Checks.

Command Descriptor Block:

CDB Fields:

Illegal Field

Reservation

Deferred Error

Unit Attention

Media Access

Diagnostic Status

7

6

5

4

3

2

1

0

0

Operation Code (11h)

1

Reserved (0)

Code

2

(MSB)

Count (n)

3
4

(LSB)

5

Control

Code

The Code field indicates what is to be spaced to:

000 Blocks—The number of blocks crossed is dictated by Count.
001 Filemarks—The number of filemarks crossed is dictated by Count.
011 EOD—Space to the end of data in the current active partition.