Abstract: An automated data storage library stores logical volumes, including logical volumes to be copied to a second library, in cache storage, and migrates logical volumes to physical media volumes stored on storage shelves. In response to a request for recalling one of the logical volumes to be copied to cache, a library controller first determines which physical media volume contains the requested migrated logical volume. The library controller identifies all of the logical volumes to be copied that are migrated and stored as stacked logical volumes on the physical media volume containing the requested migrated logical volume; selects up to “N” of the identified logical volumes, including the requested migrated logical volume; and may arrange a selection list of the selected logical volumes in a sequence in accordance with the order that the logical volumes are written on the physical media volume.

Abstract: A data storage library system with a plurality of data storage libraries and at least one director accesses a redundant copy of an identifiable data volume, employing the idle time status of each library to balance the workload. The data volumes may be stored in cache storage and backing storage which have different levels of access speed. A director requests a data volume, and the library controller of each library determines its current idle time status, providing the idle time status to the requesting director when it provides a synchronization token directly associated with the requested data volume. The token indicates the update level and the access level of the data volume in the library. The director, upon determining from the tokens that at least two of the copies of the data volume are at the same fastest available access level, compares the provided idle time status of the libraries storing those copies, and accesses the data volume from the library having the greater idle time status.

Abstract: A system and method for flushing stale data from a read prefetch buffer of a PCI bus system which transfers data in the form of data streams of contiguous blocks. The PCI bus system comprises a channel adapter at one PCI bus that issues read commands, a data source coupled to a second PCI bus, and a prefetch buffer that prefetches the blocks of read data. A prefetch counter posts the remaining number blocks to be read and transferred, posting the prefetch count at a storage location of a storage memory mapped to a prefetch location in the prefetch buffer. The prefetch count is written to the storage location by a prefetch count write command. The system for flushing stale data from the prefetch buffer comprises a key detector for sensing an unique identifier of the prefetch count write command.

Abstract: A system for limiting fracturing of write data by a PCI bus adapter which queues operation commands in a command queue. The write data is in the form of bursts comprising a plurality of contiguous words. Fracture detection logic senses fracturing of the write data. A bus arbiter is responsive to the sensed fracturing of write data by the target, and blocks access to the PCI bus. Queue level detection logic is employed, subsequent to the blocking, to monitor completion of the queued operation commands of the PCI bus target. The bus arbiter is then responsive to the queue level detection logic indicating that the PCI bus target has completed enough operations that a predetermined number (such as one) of the operation commands remain queued at its command queue, and grants access to the PCI bus to complete the burst write operation without fracturing.

Abstract: A system and method, employing a data storage device, for providing communication between a plurality of processing units which are respectively unconnected to each other, with the processing units each separately coupled to the data storage device. The data storage device is coupled to the processing units by means of peripheral or storage interfaces, each coupled to one of the processing units for receiving commands and signals sent from each of the processing units and for supplying signals to each of the processing units. A controller coupled to the storage interfaces and to a buffer, recognizes “broadcast” commands and any message accompanying the “broadcast” commands, and recognizes “read message” commands, received from the processing units.

Abstract: An automated system having removable system components is self-configured, first, determining whether configuration data is available, for example, in a non-volatile memory. If available, the processor reads a system identifier of the configuration data, compares the read and a sensed system identifier, and, if they match, ends the self-configuration. Otherwise, the system senses the removable system components, configuring the system. A sensor is moved to sense the presence or absence each of the removable system components at substantially the expected location of the component. The system operates a movable sensor to calibrate a relative position with respect to the calibration mark.

Abstract: Disclosed are a data storage library subsystem, and a method which may be implemented by a computer program product, for increasing the accessing performance of data volumes from libraries in a redundant copy synchronization token tracking system. The libraries store redundant copies of the data volumes, and have cache storage and backing storage. Updatable synchronization tokens indicate the relative update levels of the redundant copies. Each library maintains the synchronization token directly associated with each data volume; identifies each of the data volumes upon being stored in the cache storage of the library; and identifies each of the data volumes migrated to and stored in the backing storage of the library. Then, the library responds to a recall request for one of the redundant copies, providing, with the synchronization token, an indicator whether the data volume is identified as stored in the cache storage or the backing storage.

Abstract: The availability of cache storage is increased for data storage libraries which store redundant copies of identifiable data volumes, by migrating all but one of the redundant copies of the data volume to backing storage on a high priority basis. Each of the identifiable data volumes is directly associated with an updatable synchronization token, which is maintained by the data storage libraries. The synchronization token indicates the relative update levels of the directly associated redundant copies. For redundant data volumes having identically updated synchronization tokens, upon selection of the data storage library as primary, the library places the data volume in the cache storage at a low priority of a predetermined sequence, so that the data volume is maintained in cache storage and is migrated only on a low priority basis.

Abstract: A servo system and method for initializing and calibrating a track following servo for following an index servo position displaced laterally from an edge, the edge comprising the interface between two dissimilar servo signals. A servo head is moveable laterally and a servo detector determines a ratio related to the two dissimilar recorded servo signals, the ratio representing the lateral position of the servo head with respect to the edge. An independent position sensor determines the mechanical lateral position of the servo head. The servo head is nominally aligned at a lateral position at which the servo detector provides a ratio representing the edge. The mechanical lateral position of the independent position sensor is measured at the nominal alignment of the servo head. Then, the servo head is repositioned laterally the predetermined displacement distance from the nominal alignment as determined by the independent position sensor.

Abstract: A method of thermal compression bonding conductors of a multiconductor flat cable or electrical component by melting through a base layer from the reverse side of a base layer supporting the conductors. The multiconductor flat cable or electrical component comprises 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: Multiple intelligent pickers for an automated data storage library, the library having a library controller which identifies the start and end locations of the received move jobs, and places the move jobs in a job queue. The picker processor receives information over a communication link from other pickers describing movement information for the current move job of each of the other pickers. Upon completion of a move job, the picker communicates with the library controller, selecting a move job which avoids interference with the movement of the other pickers. The movement for the selected move job is determined so as to avoid interference with the stored movement profiles of the other pickers. A movement profile may be communicated to the other pickers over the communication link, and the move job is conducted according to the movement profile. Alternatively, movement information comprising the current location and vector are communicated.

Abstract: Servo track positioning information is asynchronously digitally sampled from adjoining servo tracks having different servo patterns, and varies between a maximum envelope and a minimum envelope of positioning information. An envelope follower receives the digital samples, detecting and providing a maximum envelope output measuring the amplitude of a burst envelope of the maximum digital samples, and detecting and providing a minimum envelope output measuring the amplitude of a burst envelope of the minimum digital samples. A “DROPOUT” threshold detector detects the received digital samples failing to meet a “DROPOUT” threshold related to the maximum burst envelope. An “ACQUIRE” detector responds to the “DROPOUT” threshold detection, detecting the minimum envelope for the envelope detector, which provides the minimum envelope output.

Abstract: A maximum likelihood detector and a method for maximum likelihood detection of digital samples of channel output of data recorded as analog signals representing a finite number of states. The method comprises, first, providing at least two numerical metric coefficients. The coefficients are derived from the difference between metrics directly associating “0” and “1” states of the recorded signal. The coefficients are respectively applied to each sequential digital sample to generate alternative metrics, and each respective alternative metric is compared to a previous difference metric based on a previous digital sample. Based on the comparison, one of a plurality of provided metrics is selected which minimizes the mean squared error with respect to the previous metric.

Abstract: Multiple intelligent pickers for an automated data storage library, the library having a library controller which identifies the start and end locations of the received move jobs, and places the move jobs in a job queue. The picker processor receives information over a communication link from other pickers describing movement information for the current move job of each of the other pickers. Upon completion of a move job, the picker communicates with the library controller, selecting a move job which avoids interference with the movement of the other pickers. The movement for the selected move job is determined so as to avoid interference with the stored movement profiles of the other pickers. A movement profile may be communicated to the other pickers over the communication link, and the move job is conducted according to the movement profile. Alternatively, movement information comprising the current location and vector are communicated.

Abstract: A method, a front-of-screen graphical display system, and a computer program product for controlling the speed sensitivity of a GUI cursor. GUI objects, such as icons, occupy predetermined areas of the display. First and second preselected velocity settings are provided for the cursor. A determination is made whether the cursor is located within one of the object areas of the display. If, 1) the cursor is located outside one of the object areas, the speed sensitivity for movement of the cursor by the mouse is directly related to the first preselected velocity setting. If, 2) the cursor is located within one of the object areas, the speed sensitivity for movement of the cursor is directly related to the second preselected velocity setting. The second setting is the same as or slower than the first.

Abstract: A distributed control system is provided for an automated data storage library. The library accesses data storage media in response to received commands, and comprises an accessor having a gripper for accessing the data storage media, and an XY system having servo motors for moving the accessor and the gripper. The distributed control system comprises a communication processor node for receiving commands, providing a communication link for the commands. An accessor processor node, which may be located at the accessor, is coupled to the communication processor node, the accessor processor node responsive to the linked commands, operating the gripper and providing move commands. An XY processor node may be provided at the XY system, coupled to the accessor processor node, the XY processor node responsive to the move commands, operating the servo motors. A common bus couples the communication processor node to the accessor processor node, and couples the accessor processor node to the XY processor node.

Abstract: A work queuing system and method to increase the availability of an automated data storage library for accessing and storing data storage media. At least one accessor moves the data storage media among storage shelves and data storage drives in response to work requests. The work queuing system comprises a communication processor node for receiving the work requests and for broadcasting the work requests, e.g., over a common bus network, to a plurality of work processor nodes coupled to the communication processor node and coupled to each other. Each work processor node responds to the broadcast work requests, establishing a work queue of jobs. At least one of the work processor nodes selects ones of the jobs in the work queue for an accessor and directs the accessor to conduct the selected job. The work processor nodes then synchronize the work queues.

Abstract: A wireless communication link provides picker to picker communication between multiple intelligent pickers for an automated data storage library, and provides central communication between at least one of the pickers with a central job queue. Each intelligent picker comprises a processor located thereon for operating the picker to conduct a move job and providing movement information describing movement of the picker for the current move job of the picker. The wireless communication link comprises a wireless central communication link between at least one of the pickers and a central job queue for communicating a move job to the picker processor from the central job queue, and a wireless picker to picker communication link for communicating between the pickers, each linked picker transmitting the movement information over the wireless picker to picker communication link.

Abstract: Disclosed is a server having a plurality of clients coupled to the server at client nodes, and coupled to a plurality of receivers. Events, which may range from a successful completion message to a major error alert, may be generated relating to the server or to the client nodes. A method is disclosed for dynamically selectively distributing the events to particular ones of the receivers, in response to a selective enabling/disabling of the events to each receiver. The method with respect to client nodes comprises: upon opening a session of a client node, the selectively enabled events/receivers relating to the client node are determined. Upon the selective enabling/disabling occurring during the session of the client node, the determined selectively enabled events/receivers relating to the client node are dynamically updated.

Abstract: A trace facility for a computer system attachment network, a method for operating that network, and trace tools in the network. The network has a plurality of the trace tools, each connected to a communication path, the trace facility providing a system wide trace. The trace facility comprises at least one trace buffer at each trace tool. Each trace tool has an address filter selecting an address range of information on the bus, the information being communicated on the bus as events, and storing the selected event information in the trace buffers, thereby conducting a trace. A breakpoint connection is provided interconnecting each of the trace tools. A trace tool control at each trace tool responds to a trace stop command addressed to the trace tool, to stop the trace at its address filter and trace buffer, and to issue a breakpoint signal on the breakpoint connection to all the interconnected trace tools.