Abstract: A read channel of a magnetic data storage device includes a filter to provide equalization of the signal being detected from the magnetic media. The filter utilizes coefficients for the filter response. The filter coefficients may drift sideways over time. The drift is detected and a correction is implemented by imposing a leakage on the coefficients to re-center the filter response. The leakage sign differs depending on the direction of drift detected.

Abstract: A read channel of a magnetic recording apparatus includes a filter that uses filter coefficients to process the data detected by a read head from the magnetic recordable media. The coefficients change with time and circumstances. When data is read and found to pass error detection, the filter coefficient set used for the data is stored in a memory as a last good coefficient set. Upon failure of the filtering process, the coefficient set used is replaced with a coefficient set stored in the memory as the last good coefficient set.

Abstract: A magnetic recording device write channel includes a write equalization encoder for generating a write equalization level signal and a digital to analog converter for converting the write data signal to analog signals for recording. The write equalization level signal from the write equalization encoding device controls an impedance value at an output of said digital-to-analog converter. The output of the digital-to-analog converter is connected to an input of the data transmission line which transmits the write data signal to a write head of the magnetic recording device. Variation in the output impedance of the digital-to-analog converter by comparison to the input impedance of the transmission line controls the level of the equalization transmitted to the write head of the magnetic recording device.

Abstract: For adding on to a tape automation system, a base unit is provided having at least one tape cartridge magazine having a plurality of tape cartridge receiving locations, a tape drive, a tape cartridge pickup which transports the tape cartridge from a tape cartridge receiving location after extraction to a tape drive in a first direction, a tape cartridge pickup guide along which the tape cartridge pickup travels, and an elevator system which moves the cartridge pickup guide in a second direction perpendicular to the first direction. The base unit has a removable cover. An add-on unit is provided having at least one tape cartridge magazine having a plurality of tape cartridge receiving locations. The cover is removed from the base unit and the add-on unit is placed on the base unit. The base unit elevator system is used to retrieve tape cartridges with the cartridge pickup from the add-on unit cartridge magazine and also from the base unit cartridge magazine.

Abstract: A take-up reel for a single reel cartridge magnetic tape recording and playback apparatus includes a reel assembly with upper and lower flanges and a central hub. A leader pin gripper is formed to engage a leader pin at a free end of the magnetic tape on the cartridge and is movable along a tape transport path and into an inserted position in a slot in the central hub of the take-up reel. The leader pin gripper is movable to a fully inserted position within the hub core when engaged with the leader pin of the magnetic tape. When in the fully inserted position, the leader pin gripper is secured in this position by roller arms in the hub that engage a wedge on the gripper and by a magnet mounted either in the hub or the gripper that magnetically engages a magnet or a plate in the other of the gripper or the hub. The gripper is held at reference surfaces defining a predetermined position of the leader pin hook.

Abstract: A take-up reel for a single reel cartridge magnetic tape recording and playback apparatus includes a reel assembly with upper and lower flanges and a central hub. A leader pin gripper is formed to engage a leader pin at a free end of the magnetic tape on the cartridge and is movable along a tape transport path and into an inserted position in a slot in the central hub of the take-up reel. The leader pin gripper is movable to a fully inserted position within the hub core when engaged with the leader pin of the magnetic tape. When in the fully inserted position, the leader pin gripper is secured in this position by roller arms in the hub that engage a wedge on the gripper and by a magnet mounted either in the hub or the gripper that magnetically engages a magnet or a plate in the other of the gripper or the hub. The gripper is held at reference surfaces defining a predetermined position of the leader pin hook.

Abstract: In methods and arrangements for concentrating stray magnetic fields, a pair of permanent magnets is employed in combination with a magnetic flux circuit, the permanent magnets in the pair having respective magnetizations that are oriented oppositely to each other. The permanent magnets produce a stray magnetic field that adds to a magnetic field produced by the magnetic flux circuit.

Abstract: In a system and method for failure analysis of a hardware system having an embedded specialized application computer as a firmware stored in a firmware memory and which controls and is part of the hardware system, with a snapshot dump system associated with the hardware system, detecting for an error. Upon detection of the error, a snapshot dump is initiated from memory locations providing information about conditions occurring during the error. The dumped information is stored in a memory associated with the dump system.

Abstract: In a system and method for multi-byte data compression and decompression, previously received data bytes of uncompressed data are stored. The stored previously received data bytes are compared to currently received data bytes to determine whether at least one or more of the data bytes match at least one or more of the stored data bytes. An address of matching stored data bytes is generated. In data compression, a tree module is used for the storing, comparing and generation of addresses. An optimized operation order with parallel distribution of control and data signals, and a central control word register are used to obtain high speed compression. In data compression, a memory system is provided comprising a first RAM which stores even history buffer positions and a second RAM which stores odd history buffer positions.

Abstract: A tape drive has a take-up reel assembly and a tape guide arrangement that are each selectively actuatable for interchangeable use with magnetic recording tape of a first width or a second width. The take-up reel assembly includes at least one actuatable, retractable element that can be moved between the flanges of the take-up reel assembly, dependent on the width of the tape currently being used in the drive, and the tape guide arrangement includes actuatable guide elements movable to define a width of the tape transport path across the read/write head, also dependent on the width of the magnetic recording tape currently being used.

Abstract: In a tape system and method for guiding a tape from a tape reel to a read/write tape head and then to a take-up reel, the tape is guided along a tape path such that the path surrounds the take-up reel and then begins winding on the take-up reel. With such a long tape guide path, less pressure is required on an edge of the tape for positioning the tape at the tape head.

Abstract: A tape drive has a microswitch, with a microswitch plunger, that interacts with a tape cartridge having a recess therein that is selectively closed or opened by a sliding element movable back and forth in the recess, to detect whether the recess is opened or closed and thus to enable or disenable a data transfer function between the tape drive and the tape cartridge. To protect the plunger against breakage, and to allow changing the position of the sliding element without interference by the plunger, the tape drive has a plunger protector pivotably mounted in that is interposed between the sliding element and the plunger. The plunger protector smoothly transfers forces associated with the back and forth movement of the sliding element to forces in the direction of movement of the plunger.

Abstract: A tape drive has a motor-driven take-up reel therein with a fan assembly mounted to a bottom flange of the take-up reel for co-rotation with the take-up reel. The take-up reel with the fan assembly is mounted in the tape drive so that the fan assembly draws air into the interior of the tape drive through an opening in a wall of the tape drive housing next to the fan assembly.