beautypg.com

Report density support 44h, Pre-execution checks, Command descriptor block – HP Q153090901 User Manual

Page 137: Cdb fields, Header, Report density support h 137

background image

REPORT DENSITY SUPPORT 44h

C

omm

an

ds

137

REPORT DENSITY SUPPORT

44h

The

Report Density Support

command returns details about the tape formats supported by the drive.

The data is returned as a header and a series of descriptor blocks.

Pre-execution checks

Command descriptor block

CDB fields

Header

The available length gives the total amount of data available to be returned.

Illegal Field

Deferred Error

Unit Attention

7

6

5

4

3

2

1

0

0

Operation Code (44h)

1

Reserved (0)

Media

2

Reserved (0)

6
7

(MSB)

Allocation Length

8

(LSB)

9

Control

Media

0 One descriptor block is returned for each format supported by the drive. The

capacity field in the descriptor block will indicate the capacity of the current

media.

1 One descriptor block is returned with the data for the currently loaded tape. The

capacity field will indicate the maximum for the format. If there is no tape

inserted in the drive, the drive will return CHECK CONDITION with a sense key of

NOT READY and additional sense of 3A 00h (medium not present).

Allocation

Length

This specifies the maximum number of bytes which the drive should return in its data-out

phase. Either the entire available data or allocation length bytes of the page are

returned, whichever is least.

0 No data transfer will occur. This is not considered an error.

7

6

5

4

3

2

1

0

0

(MSB)

Available Density Descriptor Length

1

(LSB)

2

Reserved (0)

3

Reserved (0)