Control unit of external storage, method for substituting defective block, and storage medium wherein control program for substituting defective block has been stored

摘要

For controlling an external storage having a block in which a datum is recorded, a control unit includes a read monitoring arrangement for monitoring whether or not failure occurs in reading the datum from the block in a data reading section. When the data reading section succeeds in reading the datum after occurrence of the failure, a data control arrangement controls the datum to be recorded in a substitute block.