Abstract: In a salient embodiment, an improved fine-positioning arrangement for mounting a recording transducer arm, comprising one or several pairs of "opposed" "piezo-flexures".

Abstract: Improved flexible disk pack magnetic storage systems and associated sub-assemblies and media are illustrated as combined with improved partition means in the embodiments, these involving a pack of flexible magnetic according disks stacked for co-rotation at high rpm on a manipulator assembly which includes a pneumatic separator-hub as the partitioner, being adapted to be shifted axially along the disk array so as to direct an air jet between selected disks and thereby selectable split the stack for entry of a transducer assembly.

Abstract: Disk drive characterized by improved means for partitioning flexible magnetic recording disks with "external" pneumatic director means for selecting a partitioning jet stream and directing it into the pack-hub, and beyond into the gap between any two disks--this means constituting rotationally-stabilized jet-select apparatus and associated jet-distributor structure.The invention avoids the problems and inconvenience of such alternate techniques as axially positioning a distributor piston within a pack-hub or of rotationally positioning (phasing) a jet nozzle relative to the co-rotating pack.

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: Shown and described are paired floppy-disk memory modules advantageously interlaced together and coupled to a CPU to provide a direct-access Mass Store Memory capability, each module comprising a pair of "short-stack" floppy disk files and an associated pair of transducer-actuator assemblies "shared" by the files.

Abstract: A disk pack cartridge opening and partitioning apparatus is described, particularly as adapted for inclusion in disk drive apparatus wherein each cartridge comprises a spreadable jacket containing a pack of compactly stacked, hole-encoded flexible magnetic recording disks. In a preferred embodiment, the apparatus provides means for automatically spreading the jacket followed by partitioning of the stack between a selected pair of adjacent disks.

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.

Abstract: Embodiment illustrates technique for better controlling "head spacing" i.e., spacing of a magnetic transducer from the recording surface of a moving medium, such as a magnetic disk -- this involving impressing signals on the recording surface (along a given track) at two prescribed frequencies, so that, upon detection of this signal, one frequency will be attenuated discriminatorily more than the other at all "erroneous" head spacings whereby a "null-seeking" servo control and associated head elevation system may be monitored to maintain optimum head spacing, (e.g., where two frequencies detected at same amplitude). Better control of head/medium spacing in non-contact magnetic recording systems is achieved, especially where one signal is a very high frequency signal which is significantly attenuated whenever there is significant spacing error, while it is readily detected at the proper spacing; while the other signal is relatively unaffected by head spacing.

Abstract: Improved partitioning subassembly, particularly as adapted for inclusion in disk drive apparatus for handling flexible disk packs, these packs preferably comprising flexible hole-encoded, disks compactly stacked in contiguous, superposed registration and packaged in a protective jacket; the subassembly, in a preferred embodiment, constituting a pair of separator-plungers adapted to operate through the encoded hole pattern to selectively and automatically partition the disk pack to enable the associated entry and manipulation of a transducer assembly into the pack.

Abstract: Improved disk drive apparatus for driving and selectively partitioning a flexible disk pack. Each pack contains flexible disks compactly stacked in contiguous, superposed registration and packaged in a protective jacket. The apparatus provides for automatic opening of the disk pack jacket, automatic selective partitioning of the disk pack therewithin, and automatic entry and manipulation of a transducer assembly into the pack for the performance of a transducing operation with respect to a surface of a selected disk.

Abstract: An improved cartridge is described comprising a jacket especially adapted for containing a pack of flexible disks compactly stacked in superposed registration. Each disk is "hole-encoded" and the jacket cooperates with the pack to permit convenient insertion and withdrawal of a disk pack while also permitting selective partitioning of the pack as well as the performance of a transducing operation on a selected disk, all while contained within the jacket.

Abstract: Improved for subassembly partitioning, particularly as adapted for inclusion in disk drive apparatus for handling flexible disk packs, these packs preferably comprising flexible hole-encoded, disks compactly stacked in contiguous, superposed registration and packaged in a protective jacket; the subassembly, in one preferred embodiment, comprising a pair of double, nested separator-plungers, each pair being adapted to operate through the encoded hole pattern to selectively and automatically partition the disk pack as well as "center" a selected disk, thereby enabling the associated entry and manipulation of a double-opposed transducer assembly into the pack, enveloping the so-centered disk.

Abstract: Disclosed is a technique for error checking in one channel or a pair of channels of a binary system in which communications is serial-by-character and parallel-by-bit, such as in digital computer-controlled magnetic tape peripherals. The system is shown as applied to the group coded recording (GCR) format and standard for half-inch, nine-track magnetic tape used for interchange among information processing systems (the USA Standard Code for Information Interchange). The technique employs equipment which generates and records on the tape, together with a set of information characters, a check (i.e., redundant) character and parity bits, the former resulting from the employment of a cyclic code and the latter being based on odd modulo 2 addition.