SCSI Commands
Page
85
Byte
Bits
7
6
5
4
3
2
1
0
0
BOP
EOP
Reserved
BPU
Reserved
1
Partition Number (0)
2
Reserved
3
Reserved
4
First Block Location, MSB
5
First Block Location
6
First Block Location
7
First Block Location, LSB
8
Last Block Location, MSB
9
Last Block Location
10
Last Block Location
11
Last Block Location, LSB
12
Reserved
13
Number of blocks in buffer, MSB
14
Number of blocks in buffer
15
Number of blocks in buffer, LSB
16
Number of bytes in buffer, MSB
17
Number of bytes in buffer
18
Number of bytes in buffer
19
Number of bytes in buffer, LSB
Field Descriptions
Field
Bytes
Bits
Description
BOP
0
7
0 = The current logical position is not at BOT.
1 = The current logical position is at Beginning-of-Partition (BOT).
EOP
0
6
0 = The current logical position is not between early-warning and
end-of-tape.
1 = The current logical position is between early-warning and end-
of-tape.
BPU
0
2
0 = First Block Location and Last Block Location fields are valid.
1 = First Block Location and Last Block Location fields are invalid.
Partition
Number
1
This field is always 0.
First Block
Location
4-7
The block address of the current logical position.
Last Block
Location
8-11
The block address of the current logical position. Always the same
as First Block Location.
Number of
blocks in
buffer
13-15
This field is not supported and is always 0.
Number of
bytes in
buffer
16-19
This field is not supported and is always 0.
Reserved
All bits are 0.
The First Block Location and the Last Block Location are both set to the number of
blocks and file marks between BOT and current logical position. If the tape is at BOT,
0 is returned in these fields. The Beginning of Partition (BOP) flag is set if the Block
Location fields are zero.
