Abstract: A runout correction pattern is recorded on the peripheral track of the disk during the initial recording of the data stored thereon. The runout correction pattern comprises an integer number of sequentially recorded groups, each comprised of an increment of full track erasure, a like increment of high transition density automatic gain control information, a first burst of servo control information, and a second burst of servo control information. Previously necessary clock tracks are not incorporated. The bursts of servo control information are recorded "off-track" by one-half of the center line to center line spacing between adjacent tracks so that all first bursts are to one side of the center line of the track and all second bursts are to the opposite side of the center line of the track.

Abstract: A pattern, useful in providing data to a processing scheme to control the fine positioning of a transducer head of a disk drive unit, comprises an erased gap followed by an automative gain control (AGC) information burst followed by a first burst of servo control information followed by a second burst of servo control information. The pattern is written on a disk by the disk drive unit using a mechanical index on an armature associated with the rotation of the disk as a primary time reference, with all other time references being based on a transition between the erased gap and the AGC burst. The first and second servo control information bursts are written alternately off track by one half of the track separation between the track of interest and the next adjacent tracks to each side thereof.