HP Surestore 80fx Optical Drive and Library SCSI-2 Command Reference - Page 58

SCSI-2 Drive Commands SCSI-2 Drive Command Set Read (Group 0) Command (08H) NOTE Table 2-17 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. The Mode Select Commands (15H or 55H) impact all read, write, format and erase commands. 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 Transfer Length PBA 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. 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. Chapter 2 2-21