Fujitsu MAG3182LC Computer Drive User Manual


 
C141-E064-03EN3 - 14
Figure 3.7 Alternate block allocation by FORMAT UNIT command
If the data block verifying operation (certification) is not permitted (DCRT flag = 0) in the
FORMAT UNIT command, the IDD checks all initialized logical data blocks by reading them
out after the above alternate block allocation is made to initialize (format) the disk. If a
defective data block is detected during the check, the IDD allocates the alternate block to the
defective data block. This alternate block allocation is made by means of alternate sector
treatment only like processing by the REASSIGN BLOCKS command even if unused spare
sectors exists in the same cylinder.
: Unused spare sector
: Defective sector
: n represents a logical data block number