Abstract: The present invention is a method and apparatus for rewriting servo information on a disk of a hard disk drive. The old servo data is erased after the new servo data has been written, using a stagger erase method. A disk pack having n sides is provided, where each of the n sides has a plurality of tracks, and each side is divided into a plurality of sectors. A first set of servo information is written on an nth sector of a track on an nth side of said disk pack. This step is repeated for n=1 through n, for every sector of the track for each side of the disk pack. Next, data is erased from one of every n sectors of the track on each side of said disk pack. The entire process is repeated for a predetermined number of tracks on each side of the disk pack. In an alternate embodiment, the data is erased from a first track while the read/write heads of the hard disk drive are being moved from the first track to a second track.

Abstract: The present invention is a method and apparatus for providing positional information of a disk. The disk has at least one side with a plurality of tracks, each having a first burst in a first servo field and a second burst in a second servo field. The first burst provides a first portion of track position information while the second burst provides a second portion of track position information. When combined, the first and second portions provide a position of a corresponding track. Each track further includes a third and a fourth burst that provides a first portion and a second portion of disk side position information. When combined, the first and second portions of disk side position information provide the disk side position of the disk. Each track also includes a burst that provides the quadrant position of the disk.

Abstract: Electronic circuitry is provided to position the read/write heads in a designated landing zone when the electrical power is removed from the drive. When power is removed from the drive, the stored energy of the rotating spindle motor is used as a source of electrical power and timing pulses to the stepper motor which drives the actuator of the disc drive. The power generated by the spindle motor as it spins down is referred to as "back EMF." A sequencer circuit is provided to couple the power and clock pulses to selected windings of the stepper motor to cause the stepper motor to rotate in the direction necessary to move the transducer heads to a predetermined park position at the inner diameter of the disc whenever power is removed from the disc drive.

Abstract: The present invention is a method and apparatus for providing positional information of a disk. The disk has at least one side with a plurality of tracks, each having a first burst in a first servo field and a second burst in a second servo field. The first burst provides a first portion of track position information while the second burst provides a second portion of track position information. When combined, the first and second portions provide a position of a corresponding track. Each track further includes a third and a fourth burst that provides a first portion and a second portion of disk side position information. When combined, the first and second portions of disk side position information provide the disk side position of the disk. Each track also includes a burst that provides the quadrant position of the disk.