Abstract: In a method for controlling a repeatable runout (RRO) compensation algorithm in a hard disk drive, it is determined whether to enable or disable an RRO compensation algorithm in a corresponding hard disk drive in a test environment while the drive is fabricated, and in a user environment. A check routine is used to determine whether to execute the RRO compensation algorithm. A determined result is written in a disk of the drive. When a user utilizes the drive, the RRO compensation algorithm is used or not used according to the determined result.

Abstract: In a method for controlling a repeatable runout (RRO) compensation algorithm in a hard disk drive, it is determined whether to enable or disable an RRO compensation algorithm in a corresponding hard disk drive in a test environment while the drive is fabricated, and in a user environment. A check routine is used to determine whether to execute the RRO compensation algorithm. A determined result is written in a disk of the drive. When a user utilizes the drive, the RRO compensation algorithm is used or not used according to the determined result.

Abstract: In a method for controlling a repeatable runout (RRO) compensation algorithm in a hard disk drive, it is determined whether to enable or disable an RRO compensation algorithm in a corresponding hard disk drive in a test environment while the drive is fabricated, and in a user environment. A check routine is used to determine whether to execute the RRO compensation algorithm. A determined result is written in a disk of the drive. When a user utilizes the drive, the RRO compensation algorithm is used or not used according to the determined result.

Abstract: In the sector number counting method of the HDD using a disk as the recording medium having a plurality of servo sectors which are divided into several servo sectors groups, so that the first sector number information of each of the divided sectors groups is recorded on an index region, the inventive method for counting the sector number according to the present invention comprises the steps of checking whether the index bit recorded on the index region is detected every time when a servo interrupt occurs, and counting and saving the sector number according to a count value of an index timer on the basis of the first sector number of the servo sectors group corresponding to the index bit after the index timer is started when the index bit is detected.

Abstract: A hard disk drive (HDD) magnetically reading and writing digital data, and measuring the track pitch of a hard disk drive to detect more accurately the position error signal on each disk. The track pitches are calculated according to heads and zones, and compared with a reference track pitch as measured and averaged over all of the disks. The track pitches corresponding to the calculated track pitches are updated when detecting the calculated track pitches are the same for less than the reference track pitch. The track pitches corresponding to the calculated track pitches measured in accordance with head number and zone number are updated when detecting that the calculated track pitches are greater than the reference track pitch.

Abstract: A technique for measuring a position error signal of a disk drive, includes measuring the width of a track by sequentially following two adjacent tracks upon turning on power, and updating a percentage of the position error signal according to the measurement of the track width.