Abstract: A disc drive includes a base and a disc rotatably attached to the base. A controller for a disc drive uses a system for mapping logical block addresses to actual location on a disc drive stores the number of skipped or defective sectors which occur prior to a target cylinder in a cylinder skip table. The system estimates a starting cylinder location for the selected logical block address. After estimating the cylinder location, a number of skipped defective sectors that have occurred prior to a cylinder start is determined. The starting location of the cylinder is slipped by this amount. A target track and associated head is also determined. Information in the track identification field is used to adjust the actual location on the track and to determine if a track seek to another track is needed.