Patent ID: 6967807

Claim:
A method of selecting physical cylinders in a disc drive having at least one rotatable disc, the disc drive including a first head, which is positionable adjacent a first disc surface, and a second head, which is positionable adjacent a second disc surface, the first disc surface having a first plurality of greycode tracks and the second disc surface having a second plurality of greycode tracks, with each greycode track of the second plurality of greycode tracks corresponding to a different greycode track of the first plurality of greycode tracks, thereby forming a plurality of greycode cylinders, wherein each greycode cylinder of the plurality of greycode cylinders comprising a pair of corresponding greycode tracks, and wherein the physical cylinders are a subset of the plurality of the greycode cylinders, the method comprising: (a) determining whether the first plurality of greycode tracks or the second plurality of greycode tracks demonstrates greater track eccentricity, to thereby obtain a maximum track eccentricity surface and a corresponding maximum eccentricity head, the maximum track eccentricity surface being one of the first and second disc surfaces and the maximum eccentricity head being a corresponding one of the first and second heads; and (b) utilizing the maximum eccentricity head to locate at least one of the physical cylinders.