Abstract: A method of handling eject requests of logical volumes received by a data storage subsystem from a host system. The method, implemented in computer readable program code, first places identified logical volumes in scratch categories. An eject request is received from a host system, to eject a logical volume from the data storage subsystem. The method responds to the eject request to determine whether the requested logical volume is in a scratch category; if the requested logical volume is determined as to be in a scratch category, a virtual media server is notified that the requested logical volume is deletable, and the virtual media server determines from its database whether the status of the requested logical volume allows deletion thereof. If the virtual media server status determining step allows deletion of the requested logical volume, the requested logical volume is deleted from both the virtual media server database and the library manager database.

Abstract: A detector and method for detecting data modulated into a timing based servo pattern prerecorded on a media, comprising shifts of pairs of non-parallel transition stripes arranged in a frame of two bursts. Timing intervals between sequential transition stripes are detected. Interval comparison logic compares selected timing intervals and indicates whether the compared intervals represent a “0”, or a “1”. First and second counters respectively increment the number of the compared intervals representing a “0” and representing a “1” in each frame. Bit comparison logic compares, for each frame, the incremented numbers representing a “0” and a “1” to a predetermined criteria and, upon one of the numbers meeting the criteria, identifies the corresponding “0” or “1” as the bit value for the frame. The bits are data comprising longitudinal position words arranged in a linear sequence.

Abstract: Disclosed are a subsystem and a method for diagnosing a fiber optic network, the fiber optic network comprising a fiber having an optic stream adhering to a defined protocol of the fiber optic network, and comprising a target for receiving and responding to the optic stream. The diagnosis comprises receiving the fiber optic stream and converting the fiber optic stream to an electrical input stream with a FOSA (fiber optic subassembly), and recognizing, from the electrical input stream, a selected event (e.g., frame or command) related to the optic stream defined protocol. Then, in response to the recognition of the selected event, recognizing a selected pattern of the electrical input stream, e.g., employing mask logic, and injecting, in response to the recognition of the selected pattern, a transmission error into the optic stream, and transmitting the optic stream with the injected transmission error to the target, employing a FOSA.

Abstract: Disclosed is a method, embodiable in computer readable program code in a network resource, for dynamically changing a network protocol management information base (MIB) module, the protocol requiring predetermined fixed fields in the MIB module. The method comprises inserting a variable in one of the predetermined fixed fields in the MIB module, and providing a first path for dynamically setting a reference to a script which substitutes for the variable, the referenced script defining a user option for operating the network resource. The referenced script operation may sense a value related to the network resource. A second path is provided to the script reference, whereby a query on the second path activates the script operation to provide the value at the MIB, and the provided value is delivered on the second path. The referenced script operation may additionally comprise conducting an operation of the network resource, and the value relates to the operation of the network resource.

Abstract: Disclosed are a method, embodiable in computer readable program code, and a system for providing server-to-server event logging. A server-to-server event message is generated including 1) an event identifier, 2) any text insert pertinent to the event message, and 3) a source trail indicating the origin and history of the event, the source trail comprising an identifier of any server forwarding the event, each identifier separated by a special character, so that the origin and any subsequently transmitting servers may be known. Further, the source trail of a received server-to-server event message is parsed to determine each identifier in the source trail, and the event message transmitted to a receiving server only if the receiving server identifier is absent from the parsed source trail, thus preventing any loops which might cause the event to be repeated.

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 method and system for limiting access to a media storage device such as a tape drive unit. In accordance with the inventive method, a set of control parameters is generated for the device for a given application program. A tape control unit uses the parameters to process commands from the application program and thereby control access to the tape. In an illustrative application, an extent is defined on the tape and controls are defined which govern the type of access permitted within the extent. The system rejects any commands which attempt to access medium outside of the defined extent. Write and formatting commands within the extent are limited and partition changes, loads and unloads are prohibited.

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: A hand held pointing device for use with a computer system having a graphic interface. The pointing device includes a body, and a communications device within the body for communicating movement signals to the computer system. The pointing device further includes a movement detection device within the body, coupled to the communications device, for detecting movement of the body by a computer user. The pointing device additionally includes a pliant outer shell having at least a portion of the body which dynamically conforms to a computer user's hand when the pointing device is held and manipulated by a computer user, such that the portion of the body which conforms to the computer user's hand provides comfort and efficient ergonomic cushioning to the computer user during computer system pointing device activities. The pointing device further includes at least one user input device for transferring data to the computer system via the pointing device.

Abstract: An apparatus for reinforcing a flexible cable has a series of alternating rigid and flexible segments that are fastened together to form a continuous support unit along most of the length of the cable. The rigid segments are preferably formed from stiff plastic while the flexible segments are formed from elastomeric material. The rigid segments typically have an elongated strip on one side of the cable, and a pair of front and rear, elongated tabs on the opposite side for clamping onto the cable. The strips and tabs have inner channels for accommodating the thickness of the cable between them. The flexible segments are soft but resilient sheet-like members that act as support hinges for the bend radii of the cable. Fasteners used to join the segments together. The cable is flexed at predefined flex points which are located adjacent to the flexible segments. The flex points do not move and are isolated between the fastened ends of the flexible segments.

Abstract: Commutators on a direct current motor run at low speed for an extended period of time get covered with a coating that makes the interface between the commutator and the brushes unreliable especially with the low speed, low current operation. This is especially true for drive motors in a data processing tape drive unit where speed control is critical. The brush to commutator interface can be cleaned by applying a very high electrical current to the motor and varying the polarity of the current with a variable duty cycle to obtain the maximum cleaning currents in a relatively short time without dismantling the motors.

Abstract: A data processing system and method for customizing a user output of a data processing system are disclosed. According to the method, a user preference for an audio or visual user output of a data processing system is determined. In response to determination of a user output having a first audio or visual frequency, the user output is mapped to a second audio or visual frequency in accordance with the user preference to obtain a customized user output. Thereafter, the customized user output is presented by the data processing system. In accordance with one embodiment, the user preference is determined by administering a test of the user's visual or aural acuity.

Abstract: A method and system for detecting the end of a tape within a tape drive system, wherein the tape drive system includes a take-up reel and a supply reel upon which the tape is wound. The tape is driven through the tape drive system at a closed loop velocity. A tension transducer located in a path of the tape is utilized to monitor a tension associated with the tape while the tape is being driven through the tape drive system at the closed loop velocity. The tension transducer is utilized to detect the end of the tape. The take-up reel is then moved through a predetermined arc of rotation, in response to a cessation of the driving of the tape through the tape drive system. A confirmation is then provided that the end of tape has been detected, in response to a particular output of the tension transducer.

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 and apparatus for testing digital read channel circuits within a data storage device includes a digital read channel circuit coupled to a simulated impulse response module are disclosed. The data storage device includes a digital read channel circuit coupled to a simulated impulse response module. A pseudo analog-to-digital waveform is generated by the simulated impulse response module is input into the digital read channel circuit. The digital read channel circuit then decodes the pseudo analog-to-digital waveform to form a set of binary data. After receiving the set of binary data, a formatter/deformatter verifies the correctness of the binary data, such that the integrity of the digital read channel circuit and the formatter/deformatter can be determined.

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 redundant array of independent disk drives (RAID) is coupled to a backplane for interfacing with a computer. Each drive in the array is mounted in a carrier. The backplane has a main power circuit and each carrier has a power conditioning and distribution circuit. Each pair of power circuits interfaces via a connectorless magnetic coupling having a core transformer with two halves. Half of the split core transformer is contained within each of the backplane and the carrier. The main power circuits deliver power to the magnetically coupled split core transformer halves, which then deliver electrical power to their respective power conditioning and distribution circuits on the carriers to provide power to the drives.

Abstract: A data processing system using a client-server configuration provides a method and apparatus for generating and managing multiple copies of client data files. A server coupled to a plurality of client systems organizes sets of storage volumes into storage pools. Primary copies of the client data files are stored in primary storage pools while additional back-up copies of the client data files are copied to secondary storage pools, called copy storage pools. A server database maintains directory information about the original client data file and reference information about the location of the multiple file copies within the server. A storage manager provides a control center within the server, directing and coordinating the transfer of files between the various storage pools, and updating the server database with directory and reference location information.

Abstract: A data processing system provides a method and apparatus for managing a shared resource between multiple processors. The data processing system includes a first processor for producing, or supplying, available sections of the shared resource, and a second processor for consuming, or allocating, the available sections within the system. The first and second processor share a memory containing a circular queue, a resource queue, for referencing available shared resource sections. The resource queue is initialized by storing a pointer to an available shared resource section in each entry of the resource queue. The second processor consumes an available section of shared resource by removing a resource pointer from a resource queue entry and sending a message signal to a mailbox message subsystem of the first processor.

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.