Servo and data format for magnetic tape having plural spaced-apart servo

Abstract

A magnetic tape has three evenly spaced-apart longitudinally-extending servo track areas. Four equal-sized longitudinally-extending data track areas are disposed between said servo track areas and between longitudinal edges of the tape and one of said longitudinally-extending data track areas. For track following, all servo track areas are simultaneously sensed for producing one head positioning signal. Data tracks are arranged into four groups of tracks, one-half of the data tracks in each group are concurrently accessed. The data tracks on the tape are arranged in clusters. Each cluster has one track from each of the groups of tracks. Two laterally-adjacent track clusters constitute four data track wraps for serpentine scanning of data tracks. The concurrent track accessing respectively occurs in first and second halves of a data track wrap (there is a number of wraps equal to one half the number of track clusters). Each servo area indicates two lateral positions of the tape to the head. The lateral spacing between the lateral positions is equal to about a data track width. This arrangement makes the servo areas field writable. The magnetic head has a number of data write and read gaps equal to the number of clusters. A set of four servo gaps are interposed between four groups of write and read gaps and positioned to simultaneously sense all three servo track areas.