Optical Drive and Library SCSI-2 Command Reference

SCSI-2 Drive Command Set
Read (Group 0) Command (08H)
Chapter 2 2-21
SCSI-2 Drive Commands
Read (Group 0) Command (08H)
This command reads data from the specified logical block address. A
maximum length of 256 logical blocks can be read using the Group 0
Read Command. If the number of logical blocks exceeds 256, use the
Group 1 Read command.
NOTE The Mode Select Commands (15H or 55H) impact all read, write, format
and erase commands.
Transfer
Length The Transfer Length field specifies the number of
contiguous logical blocks of data to be read. A Transfer
Length of 0 specifies that 256 logical blocks are to be
read. Any other value specifies the number of logical
blocks to be read.
PBA A Physical Block Address bit of 1 indicates that physical
block addressing is used. A PBA bit of 0 indicates that
logical block addressing is used.
Table 2-17 Read (Group 0) Command CDB
Byte 7 6 5 4 3 2 1 0
0 Operation Code (08H)
1 Logical Unit Number (0) Starting Logical Block Address (MSByte)
2 Starting Logical Block Address
3 Starting Logical Block Address (LSByte)
4 Transfer Length
5 PBA Reserved (0) Flag Link