REQUEST BLOCK ADDRESS
7. ATAPI Packet Command Specification
SONY AIT-1 Turbo drive SDX-470V series Ver.1.0
7-59
7.16. REQUEST BLOCK ADDRESS 02h
Bit
Byte
7 6 5 4 3 2 1 0
0
Operation Code (02h)
1
Reserved
2
Reserved
3
Reserved
4
Allocation Length (03h)
5
Reserved
6
Reserved
7
Reserved
8
Reserved
9
Reserved
10
Reserved
11
Reserved
The REQUEST BLOCK ADDRESS command reports the current position of the logical unit. No medium
movement shall occur as a result of the command. This command is used in conjunction with the SEEK BLOCK
(0Ch) command.
Note:
This command is similar in function to the SCSI-2 READ POSITION command and is supported by the
SDX-470V to allow backward compatibility with QIC-104 type devices.
Blocks are numbered sequentially, starting with 0 at BOT. Each Block, File-mark or Save Set Mark after BOT adds
one to the count.
Allocation Length: Indicates the number of bytes of the Block Address to transfer. A value of ZERO indicates that
the default data Transfer Length of 3 bytes is used.
Table 7-55: REQUEST BLOCK ADDRESS Data Format
Bit
Byte
7 6 5 4 3 2 1 0
0
(MSB)
1
2
Logical Block Address
(LSB)
The Logical Block Address fields contain the current tape position block number.