Abstract: A method and system for handling literals in a Lempel-Ziv data compression system. The literals are arranged in a storage array in an MRU/LRU format in a defined sequential MRU/LRU order, with shorter MRU/LRU reference codes assigned to the MRU literals and longer MRU/LRU reference codes to the LRU literals. Upon receiving an input literal, a selector selects the literal and a reference encoder provides the assigned MRU/LRU reference code for the literal as the output. The literals are then rearranged. An incrementor responds to the literal selection, by incrementing downward one location in the sequential order, all the literals in the storage array from the top of the MRU order to the one of the literals in the order immediately preceding the selected literal, and the selector moves the selected literal to the top of the MRU order.

Abstract: A read only input system provides a source of information for a controller of an automated data storage library, separate from the controller stored microcode, and that will be available for use by the controller after the controller microcode has been updated or restored. The read only input system comprises a bar code reader mounted on an accessor of the library and coupled to the controller for providing the output of the bar code reader to the controller, and a bar code label mounted in the automated data storage library, positioned at a predetermined fixed location. The bar code label encodes input control information for the controller, which is read by the bar code reader and supplied to the controller. The bar code label input control information may comprise an offset value for at least one of the X, Y and Z direction coordinates of the accessor in order to align the accessor.

Abstract: Disclosed is a vision system for partitioning an automated data storage library into multiple logical libraries. The system includes a positionable vision indicator having logical library indicia, which is positioned at a location where it is desired to identify storage slots for a logical library. A reader is provided for reading the indicia and for locating the positionable vision indicator. A logical library controller assigns, in response to the indicia and the location, a sequential portion of the storage slots adjacent the location to one of the multiple logical libraries. Data storage drives and I/O slots may also be identified for logical libraries. The positionable vision indicator may comprise a dummy data storage media positionable in the storage slots. Alternatively, holders are at locations adjacent groups of the storage slots and the positionable vision indicator is a label support mountable on the holders. A snap-on label support assembly may be pressed onto and engage the holders.

Abstract: A method, embodiable in computer readable program code, and a SCSI multiport device allow multiple hosts to be coupled to associated device ports of the multiport device. Using standard SCSI signaling, any host port may reserve the multiport device at its one associated device port. In response to a Reservation command, the multiport device is reserved in accordance with standard SCSI protocol. The method implements, at all the device ports other than the one device port, OFFLINE or status signaling which indicates that the multiport device is unavailable or offline. In response to a Device Reset from the one host port, the method operates the multiport device in accordance with standard SCSI protocol, including resetting the reservation of the multiport device, and additionally maintains the implemented OFFLINE or status signaling.

Abstract: A data storage system for use with a tape cartridge storing data in a serpentine pattern on tape media, and having a memory device for storing a device block map for the tape median, comprises tape drive, or a loading mechanism, which first positions the tape cartridge at memory interface for transfering the device block map from the memory device to a processor, and subsequently positions the tape media for reading and/or writing. The processor processes the device block map from the memory device for optimal retrieval of the serpentine pattern data of the tape media. The processing of the device block map occurs while the tape media is positioned for reading and/or writing, so that the processor begins the retrieval reading process immediately upon the positioning of the tape media. In another aspect of the invention, a robotic accessor of an automated data storage library moves the tape cartridge to the tape drive.

Abstract: Disclosed are a switching system and method for a Small Computer System Interface (SCSI). The SCSI has a plurality of ports coupled to devices having differing priorities including a highest priority (initiator) and lower priorities (targets). The present invention interconnects a plurality of the highest priority initiator devices to the lower priority target devices. A plurality of analog switches are each coupled to one of the initiator device ports and to the lower priority target device ports, preferably on a singular target bus, for selectively interconnecting the coupled initiator device to the lower priority target device ports. A controller is coupled to the initiator devices and to the plurality of analog switches, and is responsive to requests for connection from the initiator devices for arbitrating amongst the initiator devices to operate the analog switches to interconnect only one of the initiator device ports to the lower priority target device ports.

Abstract: Disclosed is a digital edge processor frequency control for estimating the center frequency of a recorded signal having a known format, such as data recorded on a CLV optical disk or on magnetic tape. The read channel includes a sampling detector which samples the recorded signal at a known rate to provide edge position signals (PAT) indicating the location of recorded pulse edges. An edge pattern identifier detects whether the edge signals of the recording signal match a predetermined element of the known format. Examples of predetermined elements include a pulse of a known length and whose edges are spaced a known distance, a predetermined pulse pattern, or a pulse or pattern at a known location. An interval counter is coupled to the pattern identifier for measuring the interval length between the edges of the matching pulse or pattern in units of the sample length.

Abstract: Disclosed is a compliant edge guiding and following system for recording tape. Two tape bearings are provided which define a tape path, each having a bearing surface for supporting lengthwise travel of the recording tape along the tape path. A movable tape head is positioned in the tape path between the tape bearings. The movable tape head includes a track following servo for moving the head laterally to follow lateral movement of the recording tape and maintain alignment therewith. A set of compliant tape edge guides are positioned at opposite edges of the tape path. The compliant tape edge guides of the set are a matched pair and are spaced apart laterally a distance substantially equal to the nominal width of the recording tape and positioned substantially equidistant from the centerline of the tape path. Separate sets may be positioned in the lengthwise direction on each side of, and each set closely spaced from, the movable tape head.

Abstract: In an optical data storage device for storing data on a removable optical disk in a continuous sequence of sectors or blocks, the input data buffer may be subject to under-run. An under-run detector is disclosed which is responsive to the buffered data comprising less than a sector of data for indicating an under-run, and a padding provider is disclosed which is responsive to the under-run indication for providing padding characters for formatting into sectors. The sectors may be provided with headers indicating the sectors as padding. A reading device for reading the data sectors and providing the data to a host detects padding and prevents the padding data from transmission to the host.

Abstract: A bonding opening exposing conductors through a cover of a multiconductor flat cable or electrical component to allow direct bonding thereof is described. The multiconductor flat cable or electrical component having a base layer with conductors disposed thereon and a flat cover having an opening provided therein at a bonding site, preferably by die cutting. The flat cover with the opening is laminated to the base layer, overlaying the conductors, so that the conductors are mechanically stabilized by the base layer while being exposed through the bonding opening. The shape of the multiconductor flat cable or electrical component of the present invention may be highly varied. In one embodiment, the flat multiconductor electrical component circumferentially extends around a central area, for example, totally encompassing in IC chip which may be connected to the conductors thereof at a bonding site.

Abstract: Disclosed is a combined pass through and load/unload system for automated data storage libraries. Separate portals open into each of the libraries. A pivoting robot supports a housing which is capable of supporting at least one removable multi-cartridge magazine, and pivots about a pivot axis. An actuator withdraws or extends the housing toward or away from the pivot axis. A pass through controller operates the pivoting robot to position the housing at a portal and operates the actuator to extend the housing into the portal so that the library may load and/or unload the data storage media into or out of the removable magazine(s) in the housing. The controller then operates the actuator and robot to withdraw the housing out of the portal. The controller may position the housing at the bulk load/unload position so an operator may unload and/or load magazines from the housing. The controller may position the housing at the portal of the other library to allow the transfer of media thereto.

Abstract: Disclosed are spin valve magnetoresistive heads, air bearing sliders and magnetic storage systems employing spin valve magnetoresistive heads, and methods for fabricating spin valve magnetoresistive heads and air bearing sliders employing spin valve magnetoresistive heads. The spin valve magnetoresistive head in accordance with the present invention employs two antiferromagnetic films, one exchange-coupling to the reference layer in a first direction in the read region and the other exchange-coupling to the ferromagnetic film in a second direction substantially perpendicular to the first direction in the end regions. The exchange-coupled reference layer and the first antiferromagnetic film exhibit a blocking temperature equal to or greater than 300.degree. C. The exchange-coupled ferromagnetic/second antiferromagnetic films exhibit a blocking temperature equal to or greater than 200.degree. C. The two high blocking temperatures ensure thermal stabilty during sensor operation.

Abstract: A method, apparatus, and a disk file for adjusting the height of a set of load/unload lift cams with respect to the axial height of an associated stack of disks. The method steps provide supporting load/unload lift cams with an adjustment tool, measuring the relative height of the load/unload lift cams with respect to the stack of disks in the axial direction with a non-contact transducer, and fixing the load/unload lift cams at a registered height with respect to the stack of disks.

Abstract: Disclosed is an integrated lead suspension flexure attachment structure for a micro-actuator with a slider/transducer assembly attached thereto, having a plurality of electrical terminals for both the micro-actuator and the transducer. The suspension provides low gimbal stiffness and allows the slider to have correct pitch and roll static attitudes. An attachment platform is provided for mechanically attaching the micro-actuator. Two elongate cantilever compliance members extend from the transducer edge and the opposite edge of the attachment platform. Two lead termination platforms are provided, each at the distal end of one of the compliance members. The lead termination platforms extend laterally to either side of the compliance members. Electrical leads are positioned laterally of each of the lead termination platforms on either side, and loop towards the compliance member to the lead termination platform to reduce stiffness of the leads.

Abstract: Disclosed are a method and apparatus for detecting disk drive start-up failure under disparate temperature conditions by employing a temperature sensor to measure the temperature of the disk drive at start-up. A controller selects, in response to the measured temperature, a start-up failure timing corresponding to that measured temperature. The controller then detects whether the disk drive reaches operational speed within the selected start-up failure timing. Preferably, the temperature sensor is digital. The temperature sensor may be mounted on the drive electronics card, or on electronics in the disk enclosure. The controller may have a stored lookup table relating various temperatures to start-up failure timings for selecting a start-up failure timing corresponding to the measured temperature. This method allows selection of a motor torque constant that does not compromise normal operating performance based on cold start conditions.

Abstract: Disclosed are a method and processor external to an automated data storage library for partitioning the data storage library into multiple virtual libraries for access by a plurality of hosts, each host having a host port, the data storage library having a plurality of data storage drives, a plurality of storage slots, a library controller, the library controller identifying each of the data storage drives and the storage slots, a library port coupled to the library controller, and at least one accessing robot controlled by the library controller, comprising the steps of, at a node intermediate the library port and host ports, inquiring of the host ports to identify the number of host ports; inquiring, via the library port, of the library controller to determine the data storage drive identifiers and the total number of the storage slots; identifying by employing the data storage drive identifiers, the data storage drives associated with each host port; and sequentially creating virtual libraries, assigning t

Abstract: A storage and retrieval library has a column of storage cells including at least some side-by-side storage cells. A media accessor with a picker gripper for accessing media in one side of the side-by-side cells is rotatable about a pivot to an opposed position for accessing media in the other side of the side-by-side cells. For multi-sized media, a column may have storage cells extending the full width of the column for holding a large sized media, and a second type of smaller cells arranged side-by-side, each for holding a small sized media. A media picker has a first gripper for accessing large sized media from the full width cells, and a second gripper for accessing small sized media from one side of the side-by-side cells. The media picker is rotatable about a pivot to an opposed position for the second gripper for accessing small sized media from the other side of the side-by-side cells.

Abstract: Disclosed are an automated data storage library and a method for operating the library. The library includes two pickers arranged on a common guideway; a plurality of media storage slots arranged in a plurality of regions alongside the guideway; a plurality of read/write stations arranged in regions alongside the guideway. Commands are received for jobs to move media amongst the storage slots and the read/write stations, and a controller queues the received commands and allocates the queued commands to the pickers and in an order of jobs which will allow the pickers to independently access and move the media so as to avoid interference in the same region, or in regions which are behind the other picker. The media storage slots may be arranged in row sets and regions alongside the guideway, each row set including one or more storage slots and each region including one or more columns, with the regions narrower than the pickers.

Abstract: Disclosed is a merged thin film magnetic head having a first shield layer and a combined second shield and bottom pole piece layer arranged in a sandwich supporting a read sensor therebetween at the pole tip region. The combined second shield and bottom pole piece layer are magnetically coupled with the first shield layer at the pole tip end of the yoke region adjacent the read sensor, and overlaying and magnetically coupled with the first shield layer at the back gap region. A patterned opening is provided in the combined second shield and bottom pole piece layer at the yoke region thereof to expose the first shield layer and form a flat planarization surface thereon. A plurality of stacked thin film coil layers are provided in the patterned opening, and a top pole piece layer overlies the thin film coil at the yoke region, overlies the bottom pole piece at the pole tip region providing a pole tip and gap thereat, and overlies the bottom pole piece at the back gap region.

Abstract: A magnetoresistive (MR) head and a method are disclosed providing a longitudinal bias layer and conductor leads at end regions of sensor elements to form a sensor region between the end regions. A uniform longitudinal bias thin film layer is deposited overlaying the entirety of the upper MR sensor, and a uniform conductor thin film layer is deposited overlaying the entirety of the longitudinal bias thin film layer. A photoresist process is conducted over the conductor thin film layer to develop a mask of the end regions and to expose a central region between the end regions.