Abstract: A disk drive control system including servo sectors written on a disk, with each sector containing three sets of marker pulses arranged so that three adjacent marker pulses from each of the sets spans two tracks. The pulses each comprise high frequency sinusoidal signals. Servo control depends upon the pulse amplitudes sensed by the read/write head while traversing a servo sector. The system includes an amplifier to rectify and amplify the high frequency signals, a sample-and-hold circuit to hold at least three value representative of the amplified high frequency signals, and synchronizing means to synchronize the sample-and-hold circuit such that the first value sampled and held is representative of the amplitude of the first pulse read in a servo sector, the second value sampled and held is representative of the amplitude of the second pulse read in the servo sector, and so forth. A multiplexing circuit provides multiplexed signals sequentially representative of values sampled.

Abstract: Techniques and associated apparatus for a magnetic disk transducing system adapted to record along spiral tracks in a Herringbone pattern, using a pair of orthogonal skew gaps, operating in tandem.

Abstract: Techniques and associated apparatus for a magnetic disk transducing system adapted to record along spiral tracks in a Herringbone pattern, using a pair of orthogonal skew gaps, operating in tandem.In a preferred embodiment, a pair of commonly mounted heads contemporaneously transduce along two respective spiral oppositely-skewed tracks separated by three (3) track widths.

Abstract: Improved disk drive equipment is illustrated, being characterized by improved partitioning means for partitioning a pack of flexible magnetic recording disks, the partitioning means featuring "pneumatic commutator" means for distributing air streams to various inter-disk gaps in the pack--this commutator means constituting part of an external, rotationally stabilized jet-select apparatus.

Abstract: Techniques and associated apparatus for recording and detecting data; and especially for detecting and processing recorded data with greater accuracy.Recording information (computer data bits) is recorded in "A-form" or "B-form" as oblique parallel marks along adjacent information strips (tracks) on a medium, using 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 to register with respective A-form or B-form marks.One form of mark is preferably recorded along the ODD-number tracks, at a first frequency (f.sub.1) while the other form of mark is recorded along the EVEN-number tracks at a second, different frequency (f.sub.2). Output detect means are arranged to distinguish between these frequencies for improved recording (--e.g., head-position-servo control).

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.

Abstract: Method and apparatus for providing coarse and fine radial positioning of a multiple head assembly relative to the concentric tracks of a rotatable magnetic disk. In addition to a plurality of data heads, the head assembly also includes a pair of position sensing heads having skewed core gaps disposed at an angle with respect to each other. These position sensing heads are used for prerecording concentric position control tracks on the disk as well as for subsequent sensing of position control information during both coarse and fine positioning operations. The position control information prerecorded in the position control tracks is specially chosen so as to provide a pair of pulse trains during position sensing having characteristics such that highly accurate and reliable control of head position can be achieved based upon a detection of the coincidence relationship between predetermined pulses of the respective pulse trains.

Abstract: Techniques and associated apparatus for recording and detecting data; and especially for detecting and processing recorded data with greater accuracy.Record information (computer data bits) is recorded along one or more information zones (tracks) of a medium. Head-positioning information may be derived from this, using 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.