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

A method for performing error correction code operations on data to be read from a hard disk drive, comprising:

• applying a first error correction code algorithm to a first set of data to be written to said hard disk drive;
• applying a second error correction code algorithm, different from said first error correction code algorithm, to a second set of data to be written to said hard disk drive;
• wherein said applying said first and second error correction code algorithms further comprises selecting which of said algorithms is to be applied in dependence upon the type of said data to be written to said hard disk drive;
• and
• wherein said selecting which of said algorithms is to be applied in dependence upon the type of said data to be written comprises selecting an algorithm that associates fewer error correction code bits with data that has a data time delivery priority and selecting an algorithm that associates more error correction code bits with data that has an accuracy delivery priority.

A method for operating a hard disk drive comprising:

• applying first a first error correction code to data of a first type to be written to said hard disk drive;
• and
• applying a second error correction code, different from said first error correction code, to data of a second type to be written to said hard disk drive,
• wherein said applying said first and second error correction code comprises selecting an algorithm that associates fewer error correction code bits with data that has a data time delivery priority and selecting an algorithm that associates more error correction code bits with data that has an accuracy delivery priority.

A hard disk drive system, comprising:

• a first circuit for applying a first error correction code algorithm to a first set of data to be written to a disk of said hard disk drive;
• a circuit for recording on said hard disk drive said first set of data after said first error correction code algorithm has been applied;
• a second circuit for applying a second error correction code algorithm, different from said first error correction code algorithm, to a second set of data to be written to said disk;
• a circuit for recording on said hard disk drive said second set of data after said second error correction code algorithm has been applied;
• and
• a circuit for selecting between said first and second circuits in dependence upon a predetermined error correction code selection criterion,
• wherein said selection criterion selects a first number of error correction code bits for association with data at first locations a disk of said hard disk drive at locations closer to an inner radius of said disk from a selection boundary, and selects a second number, larger than said first number, of error correction code bits to associate with data at locations closer to an outer radius of said disk from said selection boundary.

A hard disk drive system, comprising:

• a first circuit for applying a first error correction code algorithm to a first set of data to be written to a disk of said hard disk drive;
• a second circuit for applying a second error correction code algorithm, different from said first error correction code algorithm, to a second set of data to be written to said disk;
• and a circuit for selecting between said first and second circuits in dependence upon a predetermined error correction code selection criterion,
• wherein said selection criterion selects between said first and second error correction code algorithms in dependence upon the type of said data to be written to said disk, and
• wherein said selection criterion selects an algorithm that associates fewer error correction code bits with data that has a data time delivery priority and selects an algorithm that associates more error correction code bits with data that has an accuracy delivery priority.