Track-on-data technique and associated system involving di-bit recording

Abstract

Techniques and associated apparatus for positioning a magnetic transducer system relative to a selected recording track on a magnetic recording disk. Record information (computer data bits) is recorded along one or more information zones (tracks) of the disk and head-positioning information is derived from this according to a novel 'track-on-data' scheme. This scheme uses a 'di-gap' transducer system comprising at least one related pair of transducer gaps aligned to register and sense information along a common record track, with the gaps being skewed oblique to the track direction, and aligned transverse to one another. 'Servo-bits' (providing head positioning information) and 'work-bits' may both be recorded along a given track, these bits, like the mentioned gaps, being skewed relative to the track direction and aligned transverse to one another; the servo-bits in any one track thus being aligned parallel to one of the gaps while the companion work-bits are parallel to the other gap -- these gaps however being functionally interchangeable, with neither gap being dedicated to servo data or work data. Thus, once the di-gap head is moved along a given track, one gap will be aligned with the servo-bits and the other with the work-bits -- the two gaps being adapted to generate respective servo signals and data signals, the servo signal values (phase) automatically indicating the degree of head registration. Preferably, a related data encoding scheme establishes, for each track, the orientation of work-bits and servo-bits.