Read position 34h, Pre-execution checks, Command descriptor block – HP Q153090901 User Manual
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READ POSITION 34h
C
omm
an
ds
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READ POSITION
34h
The
READ POSITION
command returns data representing the current logical position to the host.
The position is the count of all marks and blocks between BOM and the current logical position.
The first block is block 0.
The command causes no tape movement.
The Read Position command is complimented by the
LOCATE
command.
Pre-execution 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 (34h)
1
Reserved(0)
Service Action
2
Reserved (0)
6
7
Allocation Length
8
9
Control
Service Action
The following values are supported:
00h
06h
08h
Short Form Block ID
Long Form
Extended Form
Allocation Length For Service Actions 00h and 06h, must be 0.