6 - 74
SONY SDT-10000/SDT-11000 DDS Tape Drive
6. COMMAND SPECIFICATION
6. 18 REQUEST BLOCK ADDRESS 02h
Bit
7
6
5
4
3
2
1
0
Byte
0
Operation Code (02h)
1
Logical Unit Number
Reserved
2
Reserved
3
Reserved
4
Allocation Length (03h)
5
Unused (00b)
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 SDT-
10000/SDT-11000 to allow backward compatibility with QIC-104 type devices.
Blocks are numbered sequentially, starting with 0 at BOT. Each SCSI Block, Filemark 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.
Bit
7
6
5
4
3
2
1
0
Byte
0
Logical Block Address (MSB)
1
Logical Block Address
2
Logical Block Address (LSB)
Table 6-46: Request Block Address Data Format
The Logical Block Address fields contain the current tape position block number.
REQUEST BLOCK ADDRESS
Summary of Contents for DDS-4
Page 177: ...3 866 308 03 ...