Optical Drive and Library SCSI-2 Command Reference

SCSI-2 Drive Command Set
Write (Group 1) Command (2AH)
Chapter 2 2-85
SCSI-2 Drive Commands
DPO A Disable Page Out bit of 1 instructs the target not to
store the data in the cache after it has been transferred
to the media.
A DPO bit of 0 instructs the target to store data in the
cache after it has been transferred to the media.
This bit is ignored.
FUA A Force Unit Access bit of 1 indicates that data is
written directly to the disk.
An FUA bit of 0 indicates that write caching is allowed.
Rel Adr A relative address bit of one indicates that logical block
address specified is a two’s complement offset from the
last logical block address accessed.
A value of 0 indicates that the logical block address is an
absolute address.
EBP An Erase By-Pass bit of 0 indicates an erase is
automatically performed before writing the data.
An EBP bit of 1 suppresses the erase operation.
Transfer Length The Transfer Length field specifies the number of
contiguous logical blocks of data to be transferred for
this command.
A value of 0 indicates that no blocks of data will be
transferred and is not considered an error.
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.
ErsCntl The Erase Control bit is identical to the Erase Bypass
bit.
NOTE For write-once optical disks, blank checking is performed before writing
data. If a written block is detected during blank checking, the drive will
return a CHECK CONDITION status. The sense key/additional sense
code will be set to BLANK CHECK/Overwrite Attempted.