Abstract: A method for rewriting track packets that fail a check-after-write test onto a track of a storage medium is presented. Local packet address information is included in the track packet itself to allow track packets to be written to the storage medium in any addressing order. This allows a single packet to be rewritten along a later track among other track packets that are being recorded for the first time, thereby reducing rewrite track overhead and eliminating the requirement for a lengthy backhitching sequence.

Abstract: A method for logically rejecting previously recorded track residue from magnetic media is presented. A session ID unique to a given recording session is encoded into track packet error check and error correction codes but is not itself actually written to tape. During a data recovery session, a reference session ID for the original recording session is acquired by reconstructing the packet session ID from the first few track packets and verifying that a predetermined number of consecutive track packets have identical packet session IDs. Once the reference packet session ID is acquired, it is preloaded into error detection and correction hardware. When a residue track encoded with a previously recorded session ID is recovered by the tape drive track packet detection circuitry, it is inherently rejected because the error detection and correction hardware detects an error and it is therefore never allowed into the data buffer.

Abstract: A multi-level error correction technique for maintaining data integrity in a data recording/recovery device is presented. Data is stored in buffer packets in a segment of a data buffer before being recorded to a storage medium. Error correction codes are generated over a plurality of instances of a plurality of buffer packet patterns in the segment, and are recorded along with all of the buffer packets onto a storage medium. During data recovery from the storage medium, recovered error correction code packets are used to perform multi-level segment correction on the recovered data packets.

Abstract: A method and apparatus for simultaneously cleaning and bonding a wire to a bonding surface is presented. In accordance with the invention, a gas is energized to form a plasma, which is then directed in a directional pressurized flow at the wire and bonding surface to form a dynamic plasma cleaning chamber bubble around the portion of the wire and bonding surface that are to be bonded together, and then the respective portions of the wire and bonding surface are bonded together within the plasma cleaning chamber bubble.

Abstract: A method and apparatus for varying track recording speed to maximize host-to-tape data transfer rates is presented. Variable data transfer rates of host systems and networks are accommodated by continually adjusting the tape speed to match the tape drive to the host's actual transfer rate. The speed of the tape is adjusted according to both the level of data present in the tape drive data buffer and whether the current mode of the drive is write mode or read mode. In the preferred embodiment, when the tape speed is accelerated or decelerated while writing a number of data track pairs to tape, a predetermined number of dummy track pairs are first written to tape at the current speed. On the next write head phase after the speed is increased or decreased as appropriate while the read heads are over the track, a predetermined number of dummy track pairs followed by more data track pairs are written to the tape at the new speed.

Abstract: A method and apparatus for reacquiring synchronization of a clock synchronization signal with a data signal in a non-tracking storage device is presented. A packet error detector detects errors in data packets from a data signal and generates a packet error status for each reconstructed packet. A read quality detector monitors the packet error status and determines whether the quality of the data signal is of an acceptable versus unacceptable read quality condition. The read quality condition is based on the number of consecutive packets in which an error is detected. Upon detection of an unacceptable read quality condition, the read channel is disabled and the clock synchronize signal is relocked to a known reference frequency. The read channel is then reenabled and the clock synchronization signal is relocked to the data signal.

Abstract: A helical scan drum design for use in non-tracking tape devices which assures 70% coverage of a track to be read by overscanning with at least two read heads at approximate 1× speed. The present invention further provides a simulation method for evaluating potential drum designs for such overscan applications. The preferred drum design uses pairs of like-azimuth read heads positioned on the rotating drum such that in combination they overlap the scan of a track by 130% the track width. These dimensions assure at least 70% coverage of each track by at least one of the pair of heads at up to 1× speed while assuring no overlap with another like-azimuth recorded track. The simulation method allows for evaluation of potential drum designs by accepting parameters describing the intended drum application and then simulating track read operations over a plurality of simulated tracks to determine the efficacy of the design over a range of tape speeds and gap widths.

Abstract: A device is disclosed for removing the information bearing surface and the data carried thereby from the substrate layer of a compact disc. The device includes a housing which has a first portion having an inner surface defining a first chamber. A second housing portion is selectively securable to the first housing portion to enclose the first chamber. A mechanism is provided for selectively mounting a compact disc within the first chamber. An apparatus is disposed within the chamber for removing the information bearing surface from the substrate layer of a compact disc positioned on the mounting mechanism by physically converting the information bearing surface to particulate material. The removal apparatus is biased against the information-bearing surface of a compact disc positioned on the mounting mechanism as the information-bearing surface is reduced to particulate material. Finally, a mechanism is provided for selectively actuating the physical removal apparatus within the first chamber.