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 1X 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 read heads having identical azimuth angles and 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 1X speed while assuring no overlap with another recorded track recorded along an identical azimuth angle. 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 helical scan tape recorder (30) comprises a rotatable scanner (84) and a transport system for transporting magnetic tape proximate the rotatable scanner in a manner so that information is recorded during a revolution of the scanner. A controller performs a pause routine (120) for pausing during a recording operation on tape. The pause routine, when executed, performs the steps of: determining a tape pause position reference value indicative of a pre-pause last recording position on the tape; recording an erase signal on the tape after the pre-pause last recording position; rewinding the tape; transporting the tape in a forward direction and obtaining a current tape position value; determining when the current tape position value reaches a predetermined value relative to the tape pause position reference value; and at beginning of a next revolution of the scanner, commencing recording of one or more post-pause stripes on the tape.

Abstract: A method and apparatus for allowing communication between a stationary circuit and circuitry in motion with respect to the stationary circuit is presented. Communication is achieved and verified by transmitting a clock signal and a control signal in synchronization with the clock signal over separate clock and control transformer channels between the stationary circuit and the moving circuitry.

Abstract: A method and apparatus for allowing communication between a stationary circuit and circuitry in motion with respect to the stationary circuit is presented. Communication is achieved and verified by transmitting a clock signal and a control signal in synchronization with the clock signal over separate clock and control transformer channels between the stationary circuit and the moving circuitry.

Abstract: A method and apparatus for allowing communication between a stationary circuit and circuitry in motion with respect to the stationary circuit is presented. Communication is achieved and verified by transmitting a clock signal and a control signal in synchronization with the clock signal over separate clock and control transformer channels between the stationary circuit and the moving circuitry.

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. jThe 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 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 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. jThe 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 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 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 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 resonant frequency control circuit communicates with a head of a disk drive and the preamplifier of a read channel. The resonant frequency control circuit is useful in achieving peaking of a readback signal generated by reading data from a magnetic disk. The read channel also includes an equalizer circuit for enhancing equalization of the readback signal. A controller communicates with the read channel and the resonant frequency control circuit for, in one embodiment, selectively adding capacitance to that capacitance which is present in the read element of the head and the preamplifier. By controlling the resonant frequency, this desired signal peaking can be achieved, which is related to the frequencies of the coded data on the disk.

Abstract: A pulse detection sensing system which provides an output signal only when a maximum voltage peak is detected. The system has a comparator which generates a comparator output signal when an output signal generated by the transducer of the system is equal to or greater than a threshold signal. The comparator is coupled to a peak follower and a sample/hold circuit which increases the voltage of the threshold signal to the level of the head output signal when the output signal attains a zero slope and has equaled or exceeded the set threshold value.