Error correction codes applied variably by disk zone, track, sector, or content

摘要

A method for performing error correction code operations on data to be read from the disk (12) of a hard disk drive (10) includes applying a first error correction code algorithm to a first set of data to be written to the hard disk drive, and a second error correction code algorithm, different from the first, to a second set of data to be written to the hard disk drive (10). The first and second error correction code algorithms may for example produce a different number of error correction code bits for application to said data. The selection between the first and second algorithms may be made, for instance, in dependence upon the physical locations (76, 78) on the disk, or in dependence upon the type of said data (80) to be written. By reducing the number of ECC bits that need be associated with at least some of the data to be written to the disk (12), the available space on the disk for user data can be increased.