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Read attribute 8ch, Pre-execution checks, Command descriptor block – HP Q153090901 User Manual

Page 111: Cdb fields, Read attribute ch 111, Command descriptor block: cdb fields

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READ ATTRIBUTE 8Ch

C

omm

an

ds

111

READ ATTRIBUTE

8Ch

The

READ ATTRIBUTE

command allows an application client to read attribute values to MAM

(Medium Auxiliary Memory). It should be executed before sending a

WRITE ATTRIBUTE

command.

Pre-execution checks:

In order to execute a

READ ATTRIBUTE

command, there must be a cartridge in the drive, even if it is

only partially loaded, so that the MAM can be read.

Command descriptor block:

CDB fields:

Illegal Field

Deferred Error

Unit Attention

Media Access

7

6

5

4

3

2

1

0

0

Operation Code (8Ch)

1

Reserved (0)

Service Action

2

Reserved (0)

4
5

Volume Number (0)

6

Reserved (0)

7

Partition Number (0)

8

(MSB)

First Attribute ID

9

(LSB)

10

(MSB)

Allocation Length

13

(LSB)

14

Reserved (0)

15

Control

Service Action

Service actions are defined as follows. The data returned for each Service Action is

described below.

Code Name

Description

00h

Attribute Values

Returns the attribute values.

01h

Attribute List

Returns a list of attribute IDs that are available (both

supported and existing IDs)

02h

Volume List

Returns a list of known volume numbers. For Ultrium

drives, there is only a single volume, Volume 0.

03h

Partition List

Returns a list of known partition numbers. For Ultrium

drives, there is only a single partition, Partition 0.

04h–1Fh Reserved