A 2,000 track/inch disk file servo system using a magnetoresistive head

A two-sided (split) magnetoresistive head has been developed for use as a position sensor in high track density servo control of recording heads on rigid disk files. The track density achieved with the head in conjunction with a selected disk servo pattern is 80 tracks/mm (2,000 tracks/in). The design of the head, the alternatives for the recorded pattern on the disk, the servo channel and servo performance are discussed.