Optical Drive and Library SCSI-2 Command Reference

SCSI-2 Drive Command Set
Mode Select (Group 2) Command (55H)
Chapter 2 2-123
SCSI-2 Drive Commands
Parameter List
Length This field specifies the length in bytes of the MODE
SELECT parameter list that the initiator will transfer
to the drive during the DATA OUT phase. A length of 0
indicates that no data will be transferred. This
condition is not considered an error.
The Mode Select Parameter List contains an 8-byte
header followed by 0 or 1 block descriptors, and followed
by 0 or more pages (see Table 2-117 on page 2-123).
Medium Type The Medium Type field will be set to 00H (default, only
one medium type supported), 02H (write-once optical
disks) or 03H (optical reversible or erasable medium).
Block
Descriptor
Length The Block Descriptor Length specifies the length in
bytes of the block descriptor, equal to 0 or 8. A Block
Descriptor Length of 0 indicates that no block
descriptors are included in the parameter list. This
condition is not considered an error.
Table 2-117 Mode Select Header
Byte 7 6 5 4 3 2 1 0
0 Reserved (0)
1 Reserved (0)
2 Medium Type
3 Reserved (0)
4 Reserved (0)
5 Reserved (0)
6 Block Descriptor Length (MSByte)
7 Block Descriptor Length (LSByte)