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6. COMMAND SPECIFICATION
6. 13 READ POSITION 34h
Bit
7
Byte
0
1
Logical Unit Number
2
3
4
5
6
7
8
9
Unused (00b)
The READ POSITION command reports the current position of the logical unit. No medium movement shall occur as
a result of the command. The position is given in two parts:
TCLP:
The Total Current Logical Position (TCLP) bit of ONE indicates the drive shall return data specifying the partition,
file, and set number with the current logical position. The TCLP bit of ZERO indicates the drive shall return data
specifying the first and last block location with the number of bytes and blocks in buffer.
LONG:
The Long Format (LONG) bit of ONE indicates the drive shall return 32 bytes of data. The LONG bit of ZERO
indicates the drive shall return 20 bytes of data.
The LONG bit and the TCLP bit shall be equal. If the LONG and TCLP bits are not equal, or if both the LONG and the
Block Address Type (BT) bits are ONE, the command is rejected with a CHECK CONDITION status and an ILLEGAL
REQUEST sense key set.
BT: The Block Address type (BT) bit controls the content of the short format data. The BT bit if one requests the drive
to return its current First Block Location shall include data block only. The BT bit of ZERO requests the drive to
return the First Block Location are a SCSI Logical Block Address (data blocks, File-marks and Save Set Marks are
counted.)
6
5
4
Operation Code (34h)
3
2
Reserved
TCLP
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
SONY SDT-10000/SDT-11000 DDS Tape Drive
READ POSITION
1
0
LONG
BT
6 - 61
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