Abstract: The invention is an interleaved electrical cable and a method of manufacture therefor. The cable is manufactured by interleaving the electrical traces of two cable subassemblies. Two cable subassemblies are manufactured and then bonded together with the traces of each subassembly interleaved with each other. The resulting interleaved fine line cable includes traces of a pitch less than that of either subassembly. Interleaved flexible cable subassemblies are also used to create the aforementioned traces of reduced pitch with one or more simple trace crossovers.

Abstract: A tape cartridge having a solid metal mount plate including a plurality of surfaces thereon simultaneously machined to the same plane. Tape reels and tape guides are affixed to the mount plate, thereby ensuring precise alignment to each other. A portion of at least one of the surfaces is exposed to the outside of the tape cartridge by recesses in the tape cartridge cover. Upon seating the tape cartridge in a tape drive, guides are inserted into the recesses, thereby ensuring precise alignment of the tape to a tape head in the tape drive.

Abstract: A first file system to assist in the storage management of a second file system not able to store its own management classes and management attributes. A repository file space in the first file system is used to accomplish the storage of some or all of the management classes or attributes for the files of the second file system. For each file in the second file system an empty file is created in the repository file space of the first file system. The creation of an empty file in the repository file space causes a management class to be selected for the file and stored in the catalog of the first file system as would be done for any file in the first file system. A naming convention is used to link each file in the repository file space with its associated file in the second file system. The additional files in the first file system are left empty as no other information need be stored for storage management purposes.

Abstract: A hydrodynamic tape guide includes a thin metal foil attached to a substrate by a pin inserted into a groove in the substrate. The groove is of a geometry including a first region of a relatively small width and at a relatively shallow depth and a second region of a relatively large width deeper into the substrate. The pin is of a thickness greater than the first width, but less than the second width.

Abstract: A tape reel brake which is mounted in a well in the top of a tape reel hub. The well is inside the tape bearing surface of the hub. The brake is mounted to be compliantly biased away from the base of the well. The hub is seated against a first inside surface of a tape cartridge housing. The hub and brake are seated in the tape cartridge such that teeth on the periphery of the brake are biased against the opposite inside surface of the cartridge housing about the periphery of an opening therein. The biasing of the brake against the opposite inside surface both prevents the rotation of the reel and shields out dust when the tape cartridge is removed from a tape drive. To rotate the reel, a tape drive clutch enters the opening in the opposite inside surface and depresses the brake into the well to mate with a smaller diameter portion of the hub or a recessed portion of the brake.

Abstract: A tape cartridge having a high performance tape path therein. The tape cartridge includes one or more gas bearing tape guides and/or one or more recesses in an edge of a gas/tape bearing surface. The gas bearing assemblies include a plenum having a metal foil gas bearing surface bonded thereto using a die-cut adhesive sheet. The compliant members are each inserted into a recess adjacent the edge of the bearing surface to permit edge guiding while providing lateral support for the tape immediately before and after the recesses in the direction of tape movement.

Abstract: An interleaved bi-directional magnetic tape head for contact recording can have a poletip enhanced by providing a thin film of a soft magnetic material deposited onto a magnetic ferrite substrate. The second pole piece is a thin film of the soft magnetic material. A closure block of a non-magnetic ceramic encloses the layers together with leveling insulation layers and a deposited activating conductor turns. The stripe poletip deposited onto the magnetic ferrite extends for a distance just short of the first conductor turn and provides a balancing of the saturation moment of the pole pieces and provides for better recording capability, especially when operating in a trailing magnetic ferrite mode.

Abstract: A tape cartridge access door includes a body having two flanges and a pseudo-head therebetween. In the open position, the access door permits a tape head to be mated with the tape in the cartridge. In the closed position, the body and flanges close openings in three adjacent walls of the tape cartridge. Also in the closed position, the pseudo-head occupies the space otherwise occupied by the tape head when the tape head is mated with the tape. The pseudo-head thus prevents the tape from being drawn taut straight when the access door is closed. The access door may pivot or slide between the open position and the closed position.

Abstract: The invention is a constrained pivot compound radius tape post guide. The post is mounted on an axle which allows it to pivot when the tape changes direction. The pivoting action serves to peel away all tape which has been in stationary contact with the post, thereby reducing startup stiction. Above a certain rotation angle the post is prevented from further rotation either by a fixed stop or by torque exerted on the post by the tape which is under tension.

Abstract: Access time is improved in a automated library system having sequentially stored data on a recording tape medium. A multiplicity of copies of the data is stored on different tape cartridges. The copies and the original are stored in different areas of the library. Each data segment stored on the tape media copy is stored in different areas of the media length from the original. The multiple copies are created and deleted independent of any user control. The usage of the original and any copies determine the number of copies and their residence times. The library manager selects the tape cartridge that can be retrieved in the shortest response time using the location of the original and the copies, the location on each cartridge of the data requested, the drive and library robot picker availability and the respective queues.

Abstract: A tape path having an implicit squeeze bearing. In such a tape path, one end of the tape is wound upon a first reel, the tape extends around one or more guides, briefly comes into close proximity with itself at the outer wrap of the tape wound upon the first reel, and is wound upon a second reel. By coming within close proximity with itself, the tape forms an implicit squeeze bearing which damps tape tension variation, inhibits the transmission of vibrations from one reel to the other, and eliminates the entrapment of entrained air without any additional rollers or other components. The tape path is suitable for use in a peripheral storage device, such as a magnetic tape drive, and is compatible with a variety of tape cartridge configurations.

Abstract: The invention is a tape guiding post including a tape engaging surface having a longitudinal contour with a compound radius of curvature. In the preferred embodiment, the longitudinal contour has a smoothly varying radius of curvature. The outer portions of the contour have a relatively large radius of curvature and blend smoothly into a central portion which is of a relatively small radius of curvature to allow for any desired bending of the tape in its easy direction. The combination minimizes both friction and stiction between the tape and the guide. The guide is also laterally contoured to accommodate droop at the edges of the tape, caused by low air pressure at the edges.

Abstract: A method for efficiently utilizing data recording media in a data processing system performing data compression beneath the level of the host processor is disclosed. To improve the ability of a recording media to be copied without increasing host processor overhead, the control unit which sees the compressed data is checked only upon recording a predetermined amount of uncompressed data. At such time, a compression ratio is calculated for the current data set and is used to monitor the recording of the remaining data of the current data set in compressed form. When a predetermined amount of compressed data is estimated to be recorded, the predetermined amount being the minimum storage capacity of a recording media, recording begins on a new recording media.

Abstract: A dual sense non-differencing peak detector locates a peak without introducing unwanted noise components, and also corrects for signal asymmetries. This is accomplished by identifying two sequential sets of two successive samples each. The first set includes samples that fall on each side of a threshold voltage on the rising edge of the signal. The second set includes samples that fall on each side of the threshold on the falling edge of the signal. For each of the two sets of samples, the point at which the signal substantially equals the threshold is found by interpolation. The two threshold points, for a symmetrical signal, fall equidistant from the peak, and hence the peak is easily located as being equidistant therebetween.

Abstract: The invention is a magnetic tape subsystem in which dropout can be controllably simulated. Such simulation is accomplished by inserting an electronic filter between the read transducer and a recording channel detector of the magnetic tape subsystem. The filter scales a spacing loss transfer function from a spatial domain to a frequency domain. After selecting an appropriate head-tape spacing, the frequency domain transfer function is computed and the filter is designed. Upon insertion of the filter, dropout is then simulated. Such simulation allows for an assessment of recording channel operation with a particular amount of dropout, including the margin to failure of magnetic tape heads or other components. Because the filter is completely electronic, dropout simulation can be performed in the field for maintenance purposes as well as to test recording channels during their development and manufacture.

Abstract: Disk storage apparatus includes a loading and unloading mechanism for moving a recording disk from an insertion position to a reproduction position within the apparatus. When the disk is in the reproduction position, a locking mechanism is moved out of contact with an actuator which carries a read/write head so that the head can be moved across the surface of the disk by a motor mounted on the actuator. When an eject command is received, the actuator is moved to an inner crash stop and the disk is moved out of the reproduction position causing the locking mechanism to move into mechanical engagement with the actuator. A magnet carried on the locking means is moved adjacent a magnet within the motor so that the mechanical locking engagement is enhanced magnetically.

Abstract: A system uses prevent and detect mechanisms to enable rewritable data storage media to be operated as a written-once-only media. A physical indication of the media casing serves as an indicator of the write-once-only status of the media. A watermark is magnetically recorded on the media at the factory with a portion of the mark detectable by the system and a portion only detectable by returning to an inspection station for verification. This protects against a complete erasure of all data from the media. A segment write status indication serves to indicate the write-once-only status of each segment of the written data. A portion of the written region, such as the preamble or control field of each segment, contains a status mark written randomly within the area as a status indication that the data was written once or multiple times within that segment.

Abstract: The invention is an optical system cleaner for an optical disk drive in which a cleaning member is attached directly to a shutter or a member corresponding to the shutter to eliminate the need for a mechanism for linking the cleaning member with the shutter. An optical disk drive according to the present invention includes an actuator for projecting an optical beam through an optical system and to a desired position on an optical disk loaded at a reproduction position. The optical disk drive also includes a shutter opening means for opening the shutter of a cassette with a built-in optical disk. The body of the optical system cleaner has a substantially similar shape to said cassette and a moving member attached to the body of said optical system cleaner so as to move freely and driven by said shutter opening means. A cleaning member is attached to said moving member for sweeping out said optical system by merely taking the body of said optical system cleaner in or out of said optical disk drive.

Abstract: In this invention, a driving circuit for moving a head in the radial direction on the recording surface of a disk is coupled to a velocity detecting circuit for detecting the velocity at which the head moves. A velocity profile is provided for storing information on the target velocity of the head. A driving signal generating circuit is coupled to the velocity profile and the velocity detecting circuit for comparing a signal from the velocity detecting circuit with a signal from the velocity profile. The driving signal generating circuit outputs a driving signal to the driving circuit based on the result of the comparison. A controller is coupled to the driving circuit for measuring a time required for moving the head a predetermined distance at a predetermined reference value, and modifying the driving signal based on the result of the comparison. Scatter in feedback quantities or fluctuation in the driving signal during velocity control is thereby corrected.

Abstract: A gimbaled compliant guide for tape drives includes two plates mounted adjacent opposite edges of an arcuate tape bearing surface. The plates are pivotably mounted to accommodate variances in the tape path resulting from tape path tolerances and tape distortions. One plate is also mounted to a leaf spring to accommodate variations in tape width. The combination of simple compliancy and the ability to pivot eliminates the concentration of the stress at a single contact point between the tape edge and the guiding mechanism. By evenly distributing the stress along the span of contact between the edge of the tape and the guides, particulate matter generated from such contact is minimized. Such guiding mechanism may be used on any element of the tape path.