Fujitsu MAP3735NC/NP Computer Drive User Manual


 
C141-E166 3-13
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
cell.
: Unused spare sector
: Defective sector
: n represents a logical data block number