Abstract: Initially, from an off-track position at a known side of, and displaced from, a servo track pattern of a tape subject to lateral movement, servo loop logic slews a tape head servo sensor laterally toward the pattern at a rate greater than the maximum rate of lateral movement of the tape. Upon detecting sensed servo signals, the logic decelerates the slewing rate. Upon detecting that the sensed servo signals are within a lock window tolerance, the logic locks a servo loop to a position error signal representing the current lateral position of the servo sensor, thereby acquiring the servo pattern.

Abstract: Directories are provided for data recorded on a magnetic tape in the form of files having data demarcation signals, such as filemarks. Data storage logic arranges a map of the tape in fixed regions; establishes a window at each intersection between fixed regions, the window extending into at least one of the regions; determines whether at least one data demarcation signal is located in a window; if so, selects and identifies the properties and location of one of the data demarcation signals as within the window. If no data demarcation signal is present, the directory indicates an absence of data demarcation signals within the window.

Abstract: Calibration of magnetic tape servo index positions, which are laterally offset from edges and measured by ratios of dissimilar servo signals. A defined signal is injected into the track following servo to modulate the lateral position of the servo sensor, which is detected by an independent position sensor. Logic converts the detected lateral positions and servo signals to frequency components; selects injected signal frequency components; converts the selected frequency components to lateral positions and servo signals, and fits a curve to the converted lateral positions with respect to the converted servo signals to calibrate the index positions.

Abstract: Disclosed is an automated data storage library for storing and retrieving data storage media in a plurality of storage slots, for a host processor. At least one drive unit is coupled to the host processor for reading and/or writing data on the data storage media. A library manager includes a stored table for identifying the data storage media stored in the storage slots, the stored table indicating artificial scaling of the data storage capacity of selected data storage media to selected values less than the actual data storage capacity thereof. The stored table also stores indicators of attributes of the library with respect to ones of the data storage media, such as indicating that the drive unit is to communicate at the drive/host interface in a specific protocol.

Abstract: A data storage drive arranged as a plurality of logical accessors accesses data on a removable random access medium. Upon a write access for a data segment by a logical accessor, a control locks a context comprising at least one data segment of a partition to the logical accessor. The control concurrently allows read access to the data of the removable random access medium, except the locked context, and allows write access, except to the locked partition, by other logical accessors.

Abstract: An automated data storage library accesses data storage media from storage shelves in response to commands from external host(s). The library receives a code update image while continuing to operate. The library is operated to an off-line status at external interface(s) that permit communication with the host(s). Then, and after the image is stored in nonvolatile memory, the processor(s) are reset, thereby activating the code update image, the processor(s) subsequently coming up from the reset to an operational state. Then, the library goes to an on-line status at the external interface(s).

Abstract: A cartridge loading apparatus has at least one movable member with a pin to engage a notch of a cartridge and has a reversible motor. A compliant link has a longitudinal leaf spring resilient beam, and has a laterally extending arm at one end of the beam, forming an “L” shape. The movable member and the motor apparatus are coupled at axes respectively at the other end of the beam and at an end of the arm. Thus, a compression force provides a rotational torque at the arm which flexes the beam outwardly away from a straight line between the axes; and a tension force provides a rotational torque to flex the beam inwardly.

Abstract: Verification system logic operates PWM motor drivers for DC motors of a tape drive, and verifies the on time duty cycle period and offset of the PWM motor drivers; verifies DAC current reference and amplifier sense signals against thresholds; and verifies Hall sensor state sequence of the DC motors during rotation. If the verifications are successful, the logic rotates the DC motors, and, for each motor, verifies the time of acceleration at a desired torque; verifies a computed velocity based on a measured velocity to a reference velocity; and verifies an actual rotation rate to a computed velocity.

Abstract: A tape movement constraint is provided for a tape drive system which moves a tape longitudinally along a tape path across a tape head, the tape having longitudinal tracks. The tape head has a track following servo system for moving the head laterally for following lateral movement of the tracks, where the tape is subject to lateral transient movement. A tape roller bearing closely adjacent the tape head is rotatable about a central axis parallel to the cylindrical peripheral surface, allowing the tape freedom of movement in the longitudinal direction. The tape roller bearing has a frictional cylindrical peripheral surface for contacting and engaging the surface of the tape and constraining movement of the tape in the lateral direction, thereby reducing the rate of the lateral transient movement of the tape to allow the track following servo system to follow the reduced rate lateral transient movement of the longitudinal tracks.

Abstract: A plurality of processing entities of a computer processing system employ messages for communicating with each other, and are updatable to newer versions at each of the processing entities by an initialization process. To maintain continuous availability, compatibility for the messages is established between the processing entities by maintaining, for message types, at each processing entity, identification values of the maximum and of the minimum versions of the message type supported at the entity. An initializing processing entity requests the maximum and minimum version identification values for the message types from other processing entities of the system.

Abstract: An indicator comprises a rotary device in the form of a right cylinder arranged to be rotatable in a chamber of a portable data storage cartridge, which has an exterior wall opening to the chamber. A peripheral surface of the rotary device has an encoded pattern of at least one cylindrical surface and a plurality of facets interrupting the cylindrical surface(s). The facets are located at various axial positions, and at various angularly spaced rotational positions, such that, at differing rotational positions of the rotary device, at least one or none of the facets is positioned at the exterior opening.

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 electrical connection of a transfer station releasably, repeatably electrically couples with respect to a matching connection of a portable cartridge. A substrate in the portable cartridge has electrical contacts on a facing surface. In the transfer station, a matching circuitized flexible substrate has electrical contacts on a facing surface thereof, which are arranged to match the portable cartridge electrical contacts when in a face-to-face relationship. An elastomeric compression element, at the rear of the matching substrate, has individual protruding compression members contacting the rear surface and registered with corresponding individual electrical contacts. Elongated electrical contacts are registered with two adjacent individual compression members.

Abstract: A method and position control for a servo system for positioning a head laterally with respect to defined servo tracks. The servo system comprises a servo sensor and detector for sensing lateral position of the head and a compound actuator having a fine actuator portion and a coarse actuator portion. The position control provides position indications for the coarse actuator portion, which may comprise a table relating predetermined nominal lateral position indications to the defined servo tracks. The position control positions the coarse actuator portion at an estimated position with respect to the defined servo tracks, and responds to the servo sensor to determine which servo track is closest to the estimated position. The position control sets the coarse actuator portion position indication to the predetermined nominal lateral position indication of the closest defined servo track, e.g., by looking it up in the table. This thereby corrects the indication of the position of the coarse actuator portion.

Abstract: Dynamic tension control for tape transported along a tape path between supply and take-up reels, driven by supply and take-up reel motors. Rotational angular velocities of the supply and take-up reels are determined from tachometers, and therefrom a linear speed for the tape at the supply reel, and a linear speed for the tape at the take-up reel are each determined. The tape linear speeds at the reels are compared to determine a delta velocity between the linear speeds. The motors are operated in accordance with a function of the delta velocity to provide a torque to at least one of the reels tending to reduce the delta velocity.

Abstract: A portable data storage drive cartridge has external interfaces positioned respectively at opposite ends of a cartridge shell. They may be arranged to be similar when the cartridge is rotated end over end to a reverse direction with respect to the opposite ends. A data storage drive, such as a magnetic disk drive assembly, having an interface, is positioned in the cartridge shell with the drive interface positioned toward a first end and away from a second end of the opposite ends of the cartridge shell. Flex cables extend from the drive interface, a first extending from the drive interface around the drive to the external interface at the second end of the cartridge shell, and a second extending from the drive interface, initially around the drive toward the second end, and reversing direction and extending back to the external interface at the first end of the cartridge shell.

Abstract: A multi-port adapter and method for scheduling jobs at the adapter input/output ports. A plurality of queues are provided, each associated with one of the input/output ports. A processor arranges the jobs in each of the queues in a normal queued order for selection by the associated port. Upon selecting a next job for one of the ports, the processor determines the number of queued jobs of each of the queues for each of the other ports; and determines whether the number of queued jobs of each queue for the other ports is less than a threshold. If the number of jobs is less than the threshold, the processor selects the next job for the one port from the jobs in the queue for the one port identified as one that may be conducted in out of queue order, e.g., having attached heuristic information; else, selects the next job for the one port from the jobs in the queue for the one port on the normal queued basis.

Abstract: A servo system and method for calibrating servo index positions of a magnetic tape for track following linear servo edges, each servo edge comprising an interface between dissimilar recorded servo signals, the edges on opposite lateral sides of a middle servo signal. A servo loop laterally positions a servo sensor where the servo signals are at estimated ratios representing the locations of the servo edges. An independent position sensor indicates the mechanical lateral position of the servo sensor at the sensed servo edges. The servo loop repositions the servo sensor to a plurality of lateral positions at predetermined displacements from the independent position sensor sensed servo edges, and track follows at each of the predetermined offsets.

Abstract: Messages for processing a database are protected during a termination and restart. An in-process message queue is coupled to a message reader and receives a copy of each read input message. A completion response detector monitors a valid completion response message to each read input message, and, upon detecting the valid completion response message, deletes the copied input message from the in-process message queue. Upon a termination and restart, a startup processor operates the message reader to read the input messages in the in-process message queue, and deletes the copied input message from the in-process message queue. The deletion thereby prevents any re-accessing of the copied input message upon a second restart, preventing a loop. The ease of termination and restart allows a special restart of the affected process of the database, rather than a system-wide termination and reboot.

Abstract: Structures are provided for mapping data of any of various formats, and for storing data of a linear sequential format, on a random access medium, e.g., having equal sized, sequentially numbered logical sectors. A third level construct comprises regions for data, identifies the region in terms specific to the format and to the sectors. A second level construct comprises a global device block map having an element for each region, identifying the format and bounds of the region in terms of the sectors and specific format, and associates related regions into partitions. A first level construct comprises a format identifier having a pointer indicating location and size of the second level construct in terms of the sectors. For data of variable length sequential device blocks, each device block has a header with multiple backwards references to close and distant previous device blocks.