3.3 Defect Management
*1 Certification is permitted when DCRT flag is cleared (DCRT flag=0) in 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.
(2)Alternate block allocation by REASSIGN BLOCKS command
When the REASSIGN BLOCKS command is specified, the alternate block is allocated to the defective logical data block specified by the initiator by means of alternate sector treatment. If there are unused spare sectors in the same cell as the specified defective logical data block, the alternate block is allocated to these unused spare sectors. However, the alternate block is allocated to unused spare sectors in the alternate cylinder when all spare sectors in the cell are used up.
: n represents a logical data block number
: Defective sector
: Unused spare sector