Format Unit Command - Adaptec ACB-4525Z User Manual

Step 2: FORMAT UNIT COMMAND
Interleave of 1:1
Three spare sectors per cylinder
Hard-Sectored Drive
FORMAT UNIT command
Hex Description
04 Op code (04h for FORMAT UNIT command)
00 Lun 0 No defect data list, format with known defect
information from primary and grown defect data lists
maintained by drive and controller and do not accept
a defect list from the host.
00 Reserved
00 High byte of interleave (must be 00)
01 Low byte of interleave
00 Reserved
The ACB-4525Z provides true device independence by automatically
formatting out all media defects by reading the manufacturer's
defect map at format time. The user may specify, through the
Mode Select command, the number of sectors per cylinder to be
left available for future use in expectation of field grown
defects. In the event of a grown defect, the Reassign Blocks
Command uses a spare sector in the same cylinder, or on maximum
cylinder - 1, to provide perfectly clean media. This intelligent
defect handling scheme eliminates performance degradation due to
media defects.
The ACB-4525Z allows the user to select the desired interleave
factor with the FORMAT UNIT command. The interleave can range
from one to the number of sectors-per-track. The number
represents the number of physical rotations of the disk which are
necessary to read an entire track of data.
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