Abstract: The invention is directed to a head positioning servo system for disk drives employing a dedicated servo surface. A plurality of servo cells are recorded on the servo surface each including a sync field for storing multiple magnetic flux transitions. Each sync field consists of multiple unit areas wherein each of said transitions is selectively stored in one or more of said unit areas. In the preferred embodiment, each sync field includes double frequency (2f) transitions which are stored in a single unit area and single frequency (1f) transitions which are stored in two adjacent unit areas. The two types of transitions are used to encode each sync field to define either a valid ("1") sync or a nonvalid ("0") sync. Valid syncs are detected to generate sync pulses for timing control to derive both rotational and radial position information from the servo surface.