Abstract: Provided are techniques for determining a reel motor angle. An estimate of an interval to degrees translation factor that represents a measurement angle interval divided by a first pulse count is calculated, wherein the first pulse count represents format transitions counted during an angular measurement interval. A reel motor angle is determined using the estimate by: receiving an indication that a rotating reference point has crossed a stationary reference point, wherein the indication is recognized as indicating that an angle between a motor rotor and a motor stator is a reference angle; determining a second pulse count, wherein the second pulse count represents format transitions counted since the indication was received to a given point in time; and at the given point in time, multiplying the second pulse count by the estimate to generate a first value and adding the reference angle to the first value to generate the reel motor angle.

Abstract: Provided are techniques for determining an angular position of a tape reel. A first edge of a hall sensor is identified. A number of format transitions on a timing based servo formatted tape are counted until detecting a predetermined edge of the hall sensor. A reel circumference is determined. A radius is determined using the determined reel circumference. A new circumference of a next revolution is determined using the determined radius and a tape thickness. A current angular position is determined using the determined new circumference and the counted format transitions.

Abstract: Provided are techniques for determining an angular position of a tape reel. A first edge of a hall sensor is identified. A number of format transitions on a timing based servo formatted tape are counted until detecting a predetermined edge of the hall sensor. A reel circumference is determined. A radius is determined using the determined reel circumference. A new circumference of a next revolution is determined using the determined radius and a tape thickness. A current angular position is determined using the determined new circumference and the counted format transitions.

Abstract: Provided are techniques for determining a reel motor angle. An estimate of an interval to degrees translation factor that represents a measurement angle interval divided by a first pulse count is calculated, wherein the first pulse count represents format transitions counted during an angular measurement interval. A reel motor angle is determined using the estimate by: receiving an indication that a rotating reference point has crossed a stationary reference point, wherein the indication is recognized as indicating that an angle between a motor rotor and a motor stator is a reference angle; determining a second pulse count, wherein the second pulse count represents format transitions counted since the indication was received to a given point in time; and at the given point in time, multiplying the second pulse count by the estimate to generate a first value and adding the reference angle to the first value to generate the reel motor angle.

Abstract: An apparatus, system, and method are disclosed for formatting a timing-based servo pattern on a magnetic tape. A first write head concurrently writes a base number of stripes to a plurality of first stripe patterns with a first and third element and writes the base number of stripes to a plurality of second stripe patterns with a second and fourth element of a first write head in response to at least one first write signal. A second write head concurrently writes an incremental number of stripes to a specified first stripe pattern to form a first incremental stripe pattern with a fifth write element and writes the incremental number of stripes to a specified second stripe pattern to form a second incremental stripe pattern with a sixth write element.

Abstract: An apparatus, system, and method are disclosed for an “M” servo pattern. A servo pattern write module is included to simultaneously create a first servo mark, a second servo mark, a third servo mark, and a fourth servo mark in an “M” servo pattern on a magnetic tape. The magnetic tape is configured to store data. The first, second, third, and fourth servo marks are substantially linear and are substantially the same length. The first and third servo marks are positioned with a forward slope comprising first and third legs of the “M” pattern. The second and fourth servo marks are positioned with a backward slope comprising second and fourth legs of the “M” pattern. Distances between center points of the first and second servo marks, second and third servo marks, and third and fourth servo marks are substantially the same.

Abstract: An apparatus, system, and method are disclosed for formatting a timing-based servo pattern on a magnetic tape. A first write head concurrently writes a base number of stripes to a plurality of first stripe patterns with a first and third element and writes the base number of stripes to a plurality of second stripe patterns with a second and fourth element of a first write head in response to at least one first write signal. A second write head concurrently writes an incremental number of stripes to a specified first stripe pattern to form a first incremental stripe pattern with a fifth write element and writes the incremental number of stripes to a specified second stripe pattern to form a second incremental stripe pattern with a sixth write element.

Abstract: Multiple servo sensors are laterally displaced over a distance less than the transverse width of timing based servo track laterally extending transitions. The servo sensors are configured to sense the transitions, and servo detection logic detects the relative timings of the laterally extending transitions sensed by the laterally displaced servo sensors as the magnetic tape is moved in the longitudinal direction. Logic is configured to determine from the relative timings of the sensed transitions for at least one known set of laterally extending transitions having differing slants, the lateral position of a servo sensor by employing the relative timing detected from one servo sensor and the relative timing detected from another servo sensor, or determine the longitudinal velocity of the magnetic tape by determining the difference between the relative timing detected from one servo sensor and the relative timing detected from another servo sensor.

Abstract: Multiple servo sensors are laterally displaced over a distance less than the transverse width of timing based servo track laterally extending transitions. The servo sensors are configured to sense the transitions, and servo detection logic detects the relative timings of the laterally extending transitions sensed by the laterally displaced servo sensors as the magnetic tape is moved in the longitudinal direction. Logic is configured to determine from the relative timings of the sensed transitions for at least one known set of laterally extending transitions having differing slants, the lateral position of a servo sensor by employing the relative timing detected from one servo sensor and the relative timing detected from another servo sensor, or determine the longitudinal velocity of the magnetic tape by determining the difference between the relative timing detected from one servo sensor and the relative timing detected from another servo sensor.

Abstract: An apparatus, system, and method are disclosed for the velocity proportional clocking of time base servo tape storage devices. The apparatus, system, and method allow the velocity of time base servo tape storage devices to be adjusted and maintained by adjusting the frequency of a clock. In one embodiment, a velocity command is received and the clock signal frequency is varied in response to the command. A feedback control signal may then be produced to control the velocity of a time base servo device in response to the clock signal frequency, the feedback control signal being used to vary the velocity of a servo motor. In one embodiment, the velocity of the servo motor varies directly proportionate to the clock signal frequency.

Abstract: A planar servo verifier head is provided comprising a plurality of magnetic head elements optimized for the readback process. The plurality of magnetic head elements are fabricated in a planar two-dimensional array in which individual elements can be used to read servo format tracks spaced across the width of a magnetic tape. In one embodiment, the magnetic head element comprises a read transducer formed of one or more turns of a sense wire inductively coupled to a magnetic yoke in a trench formed on the transducing surface of a substrate. In another embodiment, the magnetic head element comprises a read transducer formed of a thin film magnetoresistive sensor coupled to a magnetic flux guide in a trench formed on the transducing surface of a substrate. According to the method for manufacturing an embodiment of the servo verifier read head for magnetic tape recording, a plurality of trenches are formed in a nonmagnetic substrate wafer, preferably, a ceramic wafer.

Abstract: In a tape having separate servo bands of patterns positioned laterally across the tape, the patterns of a separate servo band have at least one differentiating characteristic with respect to patterns of another of the separate servo bands. The differentiating characteristic allows identification of the separate servo bands. For example, the patterns of a separate servo band have differing azimuthal orientations of detectable transitions with respect to another servo band, such as being laterally inverted. In another, variations in the width of gaps of patterns are made with respect to another servo band. In another, variations are made in the number of the detectable transitions of patterns with respect to the patterns of another servo band.

Abstract: In a tape having separate servo bands of patterns positioned laterally across the tape, the patterns of a separate servo band have at least one differentiating characteristic with respect to patterns of another of the separate servo bands. The differentiating characteristic allows identification of the separate servo bands. For example, the patterns of a separate servo band have differing azimuthal orientations of detectable transitions with respect to another servo band, such as being laterally inverted. In another, variations in the width of gaps of patterns are made with respect to another servo band. In another, variations are made in the number of the detectable transitions of patterns with respect to the patterns of another servo band.

Abstract: In a tape having separate servo bands of patterns positioned laterally across the tape, the patterns of a separate servo band have at least one differentiating characteristic with respect to patterns of another of the separate servo bands. The differentiating characteristic allows identification of the separate servo bands. For example, the patterns of a separate servo band have differing azimuthal orientations of detectable transitions with respect to another servo band, such as being laterally inverted. In another, variations in the width of gaps of patterns are made with respect to another servo band. In another, variations are made in the number of the detectable transitions of patterns with respect to the patterns of another servo band.

Abstract: Disclosed are a system, a method, and article of manufacture to provide for filtering a servo signal in a tape drive using a matched filter that is optimized for the operating tape velocity of the tape drive. A servo controller for track following on a tape uses a digital filter implementation of the matched filter to produce a filtered servo signal. The digital filter is optimized for different tape velocities by selecting digital filter coefficients for the digital filter that depend upon the tape velocity presently in use. The filtered servo signal is used by the servo controller to provide improved track following in a tape drive.

Abstract: In magnetic tape having separate longitudinal servo bands of servo information with superimposed data information, the separate servo bands have selected different superimposed data information, to identify the separate servo bands for independent addressability. The servo information comprises non-parallel laterally extending transitions to indicate lateral positioning, and the selected different superimposed data information may comprise a lack thereof in portion(s) of the servo bands. Where the superimposed data information is longitudinal position information of the tape, the selected different superimposed data information may comprise different longitudinal position information of one or more servo band(s). The selected different superimposed data information may comprise a band identifier in the superimposed data information of one or more of the servo bands.

Abstract: An arrangement for sensing the position of a leader pin on a tape which is located within a cartridge shell. The arrangement senses the position of a pin in a tape cartridge through the intermediary of either electromagnetic sensors or electrostatic detection circuitry. Additionally, provided is a method for sensing the position of a pin on a tape inside a cartridge shell by employing either electrostatic detection structure or electromagnetic sensors.

Abstract: To detect alignment and/or absence of a tape leader pin in an opening of a tape cartridge, a light source scans the opening. Detection logic analyzes the detected reflection waveform signal for deviation from a cylindrical surface reflection of the tape leader pin, if any, such as elliptical or conical, representing tilt angle misalignment of the pin. Further, both ends of the pin are scanned for difference in displacement and for difference in amplitude, displacement representing tilt in the direction of scan, and amplitude representing that one end or the other is likely to have been pulled into the cartridge. Low amplitude of both represents absence of the pin.

Abstract: To detect alignment and/or absence of a tape leader pin in an opening of a tape cartridge, a light source scans the opening. Detection logic analyzes the detected reflection waveform signal for deviation from a cylindrical surface reflection of the tape leader pin, if any, such as elliptical or conical, representing tilt angle misalignment of the pin. Further, both ends of the pin are scanned for difference in displacement and for difference in amplitude, displacement representing tilt in the direction of scan, and amplitude representing that one end or the other is likely to have been pulled into the cartridge. Low amplitude of both represents absence of the pin.

Abstract: An arrangement for sensing the position of a leader pin on a tape which is located within a cartridge shell. The arrangement senses the position of a pin in a tape cartridge through the intermediary of either electromagnetic sensors or electrostatic detection circuitry. Additionally, provided is a method for sensing the position of a pin on a tape inside a cartridge shell by employing either electrostatic detection structure or electromagnetic sensors.