User's Guide

Chapter 3 Emulated DLT7000 SCSI Commands
Read Position (34h)
240 Quantum DX-Series Software Interface Guide
Table 191 READ
POSITION Data -
Field Descriptions
Field Name Description
BOP Beginning of Partition. When set to 1, indicates that
the logical unit is at the beginning of partition in the
current partition. When 0, indicates that the current
logical position is not at the beginning of partition.
Since the tape drive does not support more than one
partition, the value of this field will be 1 when at
BOT.
EOP End of Partition. When set to 1, indicates that the
logical unit is positioned between early warning
and the end of partition in the current partition.
When 0, it indicates that the current logical position
is not between early warning and end of partition.
BPU Block Partition Unknown. This bit is never set: the
setting of the Block Type (BT) bit of READ
POSITION CDB does not affect the block address
values returned.
First Block
Location
The block address associated with the current
logical position: the next block to be transferred
between the target and initiator if a READ or
WRITE command is issued.
Last Block
Location
The block address associated with the current
physical position: the next block to be transferred to
tape medium and from the target’s buffer. If the
buffer is empty, or has only a partial block, the same
value as First Block Location is reported. The first
block or filemark written onto the tape medium is at
address 0.
Number of
Bytes in
Buffer
The number of data blocks in the target’s buffer.
Number of
Bytes in
Buffer
The number of data bytes in the buffer that have not
been written to the tape medium.