Abstract: The method of the present invention is useful in a computer system having a user interface, a memory, a repository and a database. The method is a repository program executed by the computer system for locating a versioned object within a history of objects stored in the repository.

Abstract: The method of the present invention is useful in a computer system having a user interface, a memory, a database and a repository operative in the computer system for accessing the database. The method is implemented by the computer system for collapsing a version tree that depicts a history of objects stored in the database. The method, which is stored in the memory at run-time, comprises the steps of validating collapse request by insuring that the target object is not a ghost object, the end object is not a ghost, the end object is on the same version tree as the target object, and the end object is a later version than the target object. An empty array representing path objects is initialized from the target object to the end object; and if an end object is supplied, a function is called to build up an array of objects representing paths from the target object to the end object. The array of objects built up in the preceding steps is processed.

Abstract: A method is disclosed that enables changing of print commands for traditional line printers to character highlighting capabilities offered by modern non-impact type printers. The disclosed method provides a technique to look ahead in a stream of data to be printed and determining if a modification of the print is to occur. If so, a table of attributes is provided for indexing to the changed character for transmission to the printer.

Abstract: The disclosed invention is a method in a computer peripheral control system for initializing and monitoring operations of a plurality of peripheral device controllers. The system includes more than one master controller. The method comprises the steps of storing in registers of the master controllers an initial set of parameters for operation of the control system, executing a self test of each of the master controllers to determine if any errors have occurred; and if so, checking to verify presence of a redundant master controller. The method further includes detecting whether or not the redundant master controller is in control; if not, setting bus active control signals; enabling active clock output signals; initializing status bus address pointer; polling a selected one of the peripheral device controllers; checking for end of cabinet address; incrementing status bus address pointer; and repeating the steps of initializing through incrementing.

Abstract: In a computer system having a user interface, a memory, a repository and a database, a repository program operating in the computer system for accessing the database, the repository program executing a method for supporting modeling, the method comprising the steps of examining a collection of types forming a model; sorting object types into data and persistent type objects; creating all data type objects and adding to a collection of all objects owned by the model; creating all persistent type objects and adding to a collection of all objects owned by the model; initializing all persistent type objects in the collection of objects.

Abstract: The present invention is useful in a data processing system having a data processor coupled to a SCSI channel disposed for transmitting and receiving data between the data processor and a peripheral storage subsystem. The present invention is a method for controlling a bridge controller that permits expanding the maximum allowable number of disk drives connectable to the SCSI channel. In particular the method comprises the steps of receiving a command from the SCSI channel; initializing queue pointers from a memory in response to the command; determining the command type and setting flags and pointers in response thereto; when the command is a write operation, transferring data from the SCSI channel and storing the data in the memory; selecting a disk drive to receive the data by sending message and command bytes to the disk drive; and, transferring the data from the memory to the selected disk drive.

Abstract: The method of the present invention is useful in a computer system having a user interface, a memory, a repository and a database. The method is a repository program executed by the computer system for maintaining a history of objects stored in the repository. The method comprises the steps of determining if the object is a new logical object, and if so constructing a new versioned object; and, if not retrieving from the repository an object on which a new state is to be based. If the new state is being derived from only one object, then reserving the object. If the state is being derived from two objects, then retrieving from the repository the other object on which the new state is based, and merging the two objects. If the state changes are to be retained, then replacing the object; and, if the state changes are not to be retained, then unreserving the object.

Abstract: In a data processing system having a data processor coupled to a SCSI channel disposed for transmitting and receiving data between the data processor and a peripheral storage subsystem, a bridge controller for expanding the maximum allowable number of disk drives connectable to the SCSI channel. The bridge controller comprises a microprocessor having input/output terminals coupled to a CPU bus; a memory having input/output terminals coupled to a DMA bus; a buffer coupled between the CPU bus and the DMA bus; a first transceiver coupled between the DMA bus and the SCSI channel; a second transceiver coupled between the DMA bus and the disk drives; and, a circuit for controlling the direction of data flow through the buffer. The circuit has input/output terminals coupled to the CPU bus and a control output coupled to a direction control input terminal of the buffer.

Abstract: In a computer system having a user interface, a memory and a database, a repository program operating in the computer system for accessing the database, the repository program executing a method for treating a group of objects as a single object. This method comprises the steps of retrieving a collection of references for a type from the repository; sorting out each reference in the collection of references that are composite references and have a versioned object type; for each sorted reference, retrieving objects from the reference; and calling up current operations for each retrieved object.

Abstract: The present invention is useful in a data processing system having a data processor coupled to a SCSI channel disposed for transmitting and receiving data between the data processor and a peripheral storage subsystem having a multiplicity of disk drives. A method for assuring fair access to all disk drives connected to the SCSI channel by assigning a weighted value to I/O commands when they are issued to the SCSI device. The weighted value is determined on the basis of the length of the data to be transferred by the device. The greater the length of the data to be transferred, the larger the weighted value assigned thereto.

Abstract: The disclosed invention is an apparatus in a computer peripheral device for determining the direction of signal flow and data flow on a SCSI bus, which apparatus comprises a time delay means responsive to status signals of the SCSI bus. The time delay means generates a signal that defines an arbitration selection period of time for determining control of the SCSI bus. The apparatus further includes a first circuit means responsive to the arbitration selection signal and status signals of the SCSI bus. The first circuit means generates a plurality of signals that determine whether the peripheral device is an initiator of signals to be transmitted on the bus or is a target for receipt of signals present on the bus. Moreover, the apparatus includes a second circuit means that is responsive to the plurality of signals generated by the first circuit means and status signals of the bus. The second circuit means generates a pair of signals indicative of the direction of data and signal flow on the SCSI bus.

Abstract: The disclosed invention is a unique apparatus for converting signal formats. For example, the apparatus can convert from a single-ended to a differential format without the necessity of additional control circuitry. A cross-circuit arrangement prevents an undesired reversal of direction for conversion of signal formats.

Abstract: An alternate path selection structure is provided which reduces the effects of aborting an operation. The present invention comprises a structure and method that allows efficient retrieval of alternate paths to pursue in a microcode sequence.

Abstract: An apparatus is disclosed that provides control of access to a module. In particular, the module should not be accessed while in a busy or unstable state. The module disclosed herein, by way of example, is a timer module. Access to the timer is controlled by the disclosed apparatus while the timer is changing state.

Abstract: A digital device time-multiplexes the execution of multiple tasks that are defined by respective sequences of control words in a control memory. In this device, the time-multiplexing is performed by sending control signals that are representative of respective resume addresses along with each output message sent by the device that calls for a response. These response messages are thereafter received by the device along with the control signals that were sent with the corresponding output message. Received response messages are thereafter operated on by the device by executing control words in the control memory beginning at the resume address represented by the received control signals.

Abstract: Disclosed is a static semiconductor memory which is comprised of a pair of cross-coupled switching means forming a set-node, a reset-node, and a common-node; and a pair of variable conductance means. Each of the variable conductance means are characterized as having first and second terminals with negligible conductance therebetween when the voltage thereacross is less than a predetermined breakdown level, and as having substantial conductance when the voltage thereacross exceeds the breakdown level. The first terminals of the pair of variable conductance means are coupled respectively to the set-node and reset-node. A pair of bit lines are coupled respectively to the second terminals on the pair of variable conductance means; and a word line is coupled to the common-node.

Abstract: A battery feed circuit with a current-controlled feedback loop supplying DC current to a load. The circuit is particularly adjustable to telephone systems and is characterized by low power dissipation.