Product manual

SCSI Description
5-142 Maxtor Atlas 10K IV
5.49 WRITE LONG Command (3Fh)
The WRITE LONG and READ LONG commands allow the initiator to issue raw
reads and writes of physical sectors addressed as logical blocks with an assumed
sector length of 512 bytes. These commands are used to verify the correction
capability of the drive's ECC and to create defects of a known kind and location to
verify the drive's recovery and bad sector handling policies. The data format and field
descriptions are shown in Table 5-214 and Table 5-215 respectively.
Table 5-214 WRITE LONG Command Descriptor Block-Data Format
Table 5-215 WRITE LONG Command-Field Descriptions
Bit
Byte
765 4 3210
0 Operation Code (3Fh)
1 Reserved RelAdr
2 - 5 Logical Block Address
6 Reserved
7 - 8 Byte Transfer Length (562)
9Control
Field Description
RelAdr Relative Address. This drive does not support this feature; the field must be 0.
Logical Block
Address
The address of the first logical sector where the Write operation will occur.
Byte Transfer
Length
Must be 562. This value reflects the number of bytes spanned by the ECC, including
the ECC itself, rounded up to the next word (this is easiest understood in bits: 4096
data bits + 1 force error bit + 15 Logical Block Address bits + 16 cross check bits + 2
pad bits + 360 ECC bits + 6 pad bits that are not written to media but are only needed
for transfer = 4496 bits or 562 bytes). Any other value in this field results in a CHECK
CONDITION status and the appropriate sense data.
The initiator should first issue a READ LONG, then modify the data portion only, and
then issue a WRITE LONG. It is also recommended that the drive be reformatted after
these commands are used.