Abstract: A fault tolerant memory control system is provided for a computer system having a host processor, a memory and a system interconnect. The memory control system includes a primary memory controller and a backup memory controller with a tap coupled to the interconnect. Data is transferred from the host processor to the memory in the form of data packets. First, the host processor writes to the memory by sending a data packet to the primary memory controller which then caches the data from the data packet. The backup memory controller taps the interconnect to obtain a backup copy of the data packet as the data packet is being sent from the host processor to the primary memory controller which caches the data from the backup copy of the data packet. If the primary memory controller is functional, the primary memory controller sends the data to the memory via a primary path coupling the primary memory controller to the memory. Conversely, if the primary memory controller fails, i.e.

Abstract: Symmetry in a filter is used to reduce the complexity of an interpolator or a decimator. A weight filter matrix which includes L=(N-1)M+K weights is divided into two sub-filters, the first having L1=NK weights and the second having L2=(N-1)(M-K). For interpolators, N source samples are applied to the first sub-filter to produce K signals and N--1 source samples are applied to the second sub-filter to produce M-K signals. For decimators, K source samples are applied to the first sub-filter to produce N samples and M-K source samples are applied to the second sub-filter to produce N-1 samples. An inverse relationship is recognized when a first weight is associated with a first of the samples and a second weight with a second of the samples and a weight equivalent to the first weight is associated with the second sample and a weight equivalent to the second weight is associated with the first sample. Two composite weights of the first and second weights and composite sample signals weighted therewith are formed.

Abstract: Virtual bus stubs, which can be distributed among constituent computers of a computer network, and a central resolver cooperate to simulate a bus which is connected between multiple circuit parts of a simulated circuit. With each simulated cycle of a clock of the bus, the resolver (i) collects data from the virtual bus stubs representing signals driven on the bus by one or more of the circuit parts, (ii) resolves the current simulated state of the bus from the collected data, and (iii) sends data representing the resolved current simulated state of the bus to the virtual bus stubs. As a result, the virtual bus stubs and the resolver collectively accurately simulate the bus connecting the circuit parts. Since each circuit part has access to the simulated state of the bus through a respective virtual bus stub, each circuit part has access to all information regarding the simulated state of simulated circuit which is necessary for the accurate simulation of each circuit part.

Abstract: Various components of a color pixel stored in an accumulation buffer and respective components of a color pixel in a frame buffer are processed substantially simultaneously in partitioned multiplication operations and partitioned addition operations. An accumulation buffer weight is substantially multiplied by each component of the buffer pixel substantially simultaneously in a partitioned multiplication operation. The weighted buffer pixel is adjusted in some embodiments to effectively increase the range of accumulation buffer weights which can be effectively processed by the processor. For example, the weighted buffer pixel is doubled to effectively extend the effective range of the accumulation buffer weight from approximately -0.5 to 0.5 to at least the range of approximately 0.0 to approximately 1.0.

Abstract: An automatically switching valve measures pressure at an outlet line using an electric, pressure-sensitive switch which can be set to close at a predetermined pressure threshold within relatively narrow tolerances such that a pressure regulator can be placed between the pressurized gas supply tanks and the switching valve. Closing of the pressure-sensitive switch in response to the drop in pressure below the predetermined threshold sends an electric signal to a relay. In response to the electric signal, the relay causes a different inlet line to be selected, thus changing the particular pressurized gas supply from which the outlet line receives pressurized gas. When gas is supplied through a first inlet line, an electric signal from the pressure-sensitive switch causes the relay to toggle to supply gas through a second inlet line. A subsequent signal from the pressure-sensitive switch causes the relay to toggle back to again supply gas through the first inlet line.

Abstract: A merge computer instruction is capable of interleaving respective bytes of two four-byte words and is used once to group most significant bytes and least significant bytes of first and second pixel components represented in a two-byte format and to group most significant bytes and least significant bytes of third and fourth pixel components represented in the two-byte format and a second time to group the most significant bytes of the first, second, third, and fourth pixel components and to group the least significant bytes of the first, second, third, and fourth pixel components. The least significant bytes of the first, second, third, and fourth pixel components represent the first, second, third, and fourth pixel components in a one-byte format and are stored as the respective pixel components in the one-byte format. Thus, four pixel components are converted from a two-byte format to a one-byte format using only two computer instructions.

Abstract: The appearance of symmetrical lateral movement such as the flapping of a bird's wings is provided by a rotating vane which has a light side and a dark side. The vane is generally elliptical in shape and is divided into two blades. Each of the blades is curled about an axis which is generally parallel to the axis of rotation of the vane. Accordingly, rotation of the vane alternately shows the light and dark sides of the vane such that the light side of the vane appears from a distance to be moving along the axis of rotation about the center of the axis of rotation. The vane is rotatably attached to an animal decoy, such as a duck decoy, by a support. The curvature of the vane causes the vane to rotate in response to a wind force. During rotation, the top of the vane moves away from the head of the decoy and the bottom of the vane moves toward the head such that any lift generated by rotation of the vane is directed upwards to lift the decoy slightly out of the water rather than drive the decoy into the water.

Abstract: A base test class is defined in an object-oriented computer program development environment and members of the base test class, i.e., test objects, represent individual test processes in a computer. The base test class defines a number of attributes and member functions which are inherited by test objects including a constructor member function which is performed when a test object is created. Creation of a test object performs substantially all that is required to implement interfaces and protocols (i) for interaction between the test object and simulation systems, (ii) for synchronization of processing of the test object with processing of other test objects and with simulation systems, and (iii) for reservation by the test object of devices of simulation systems. In addition, a base device class defines a number of attributes and member functions which are inherited by device objects. Device objects represent devices of simulation systems which interact with the test process.

Abstract: Data elements which can be combined to define a state are defined by respective attributes of an attribute set. An attribute includes an identifier, a data type, an accessor, and procedures for storing and retrieving values of the data element. A context includes at most one value for each attribute of an attribute set. Different contexts can have different respective values for the same attribute. Since an attribute includes a data type and procedures for storing and retrieving values of the attribute, type checking error detection mechanisms of the computer instruction language in which the attributes are implemented remain in effect. In addition, attribute values are stored in an ordered structure, e.g., an ordered list, in each context and the location within the ordered structure at which an attribute value corresponding to a particular attribute is stored in the particular attribute. As a result, attribute values are accessed within contexts in a particularly efficient manner.

Abstract: Each node of a failing distributed computer system, e.g., as a result of a split-brain failure, races to achieve a quorum by successfully reserving two shared storage devices which are designated quorum controllers. During normal operation of the distributed computer system, each of the quorum controllers is associated with and reserved by a respective node. During the race for quorum in response to a detected failure of the distributed computer system, each node which has not failed forcibly reserves the quorum controller which is associated with the other node. If a node simultaneously holds reservations for both quorum controllers, that node has acquired a quorum. The forcible reservation of a shared storage device does not fail even if another node holds a valid reservation to the same storage device. Accordingly, a failed node which does not relinquish a reservation to the node's quorum controller cannot prevent another node from acquiring a quorum.

Abstract: A compact disc coaster includes a soft, substantially non-scratching material on an upper surface which is adapted to receive a compact disc. Specifically, the compact disc coaster is adapted to receive a compact disc by including a recess which is substantially the size and shape of a compact disc. A user places a compact disc in the compact disc coaster by simply dropping the compact disc into the recess. Since the compact disc is not slid into position, the underside of the compact disc is not slid along any material for any appreciable distance. Accordingly, dirt or particles in the recess of the compact disc coaster do not scratch the underside of the compact disc and therefore do no cause data errors in the compact disc. The compact disc coaster includes a relatively high-friction bottom surface which prevents slippage of the compact disc coaster from a relatively flat surface on which the compact disc coaster is placed.

Abstract: Collisions in access to a simulated device are avoided by reserving to one of two or more hardware simulation tests the simulated device. Deadlocks involving requests of multiple tests for reservation of devices are prevented by establishing the order in which such requests are served and requiring that a test must first relinquish reservation of all devices prior to reserving additional devices. Thus, when the additional requests are appended to a queue of pending reservation requests, no test whose requests follow the requests of a second test in the queue can reserve a device requested by the second test. In other words, the situation in which each of two or more tests has reserved a device, reservation of which is required by another of the two or more tests, cannot occur. Starvation is prevented by combining the sorted queue of each reservation phase into a sorted "round robin" arrangement.

Abstract: End-to-end call processing of an ISDN-BRI central-office switch is simulated using a polled multi-tasking method which is executed by a single microcomputer in an ISDN-BRI central-office emulator which includes (i) a packet handler, (ii) a time-space multiplexer, (iii) an in-band tone generator, and (iv) a plurality of dual-interface line modules, each of which includes a U-interface loop termination device and an S/T-interface network termination device. The method includes controlling the packet handler to simulate packet-handling functions required for ISDN signalling and ISDN data exchange, controlling the time-space multiplexer and in-band-tone generator to simulate at least one of the circuit mode voice and data connections functions of the ISDN-BRI central-office switch, and activating either the U-interface loop termination device or the S/T-interface network termination device of at least one of the dual-interface line modules.

Abstract: A Method for increasing data-processing speed in computer systems containing at least one microprocessor (1), a memory device (3), and a cache (2,4) connected to the processor, in which the cache (2,4) is arranged to fetch data from the addresses in the memory device (3) requested by the processor (1) and then also fetches data from one or several addresses in the memory device (3) not requested by the processor (1). The computer system includes a circuit called the stream-detection circuit (5), connected to interact with a cache (2,4) such that the stream-detection circuit (5) detects the addresses which the processor (1) requests in the cache (2,4) and registers whether the addresses requested already existed in cache (2,4) . The stream-detection circuit (5) is arranged such that it is made to detect one or several sequential series of addresses requested by the processor (1) in the cache (2,4).

Abstract: A pixel of a color video image is converted from one color format having luminance and chrominance signals, e.g., YUV format, to a destination format, e.g., RGB or CMY formats, by forming luminance and chrominance component words which include partitioned words representing various color components of the luminance and chrominance signals. The luminance and chrominance component words are summed using a partitioned addition operation to thereby accumulate the various color components of the luminance and chrominance signals simultaneously and in parallel. Formation of the luminance and chrominance component words is, in some instances, done by a load and store unit of a central processing unit while a graphics execution unit simultaneously sums the luminance and chrominance components using the partitioned addition operation. By using this technique, conversion of pixels of a color motion image from YUV format to a different format, e.g.

Abstract: An S8ED system is implemented in a memory system to detect single errors involving one or more bits in a byte of subject data, stored in and retrieved from the memory system. Relationships between the subject data and parity data, which are used to detect errors in the subject data, are defined by a novel check matrix. The novel check matrix includes a number of constituent matrices, each of which includes eight (8) vectors. Each vector of a constituent matrix (i) has a number of elements which is equal to the number of parity bits used to detect errors in the subject data; (ii) is a concatenation of a building block vector, one or more instances of one of two base generating vectors, and one or more instances of the other of the two base generating vectors; and (iii) is distinct from all other vectors of the same constituent matrix.

Abstract: Relationships between first one of a number of graphical objects, such as windows, displayed in a computer display device and several others of the graphical objects are displayed to the user in the form of a relationship window in response to an event associated with the first graphical object. The event, e.g., a resize event in a view relationships mode, is one in which the user selects the first graphical object whose relationships are of interest and specifies a position within a computer display device in which to display the relationship window in a single gesture. For example a resize gesture by the user selects a graphical object and directs display of the relationship window since resize gestures are commonly implemented in conventional graphical user interfaces and are therefore familiar and intuitive to the user.

Abstract: A power output amplifier for use with electric guitar wherein the individual pairs of power tubes are of two or more differing types which may be selected by the user to operate alternately or simultaneously.

Abstract: A Runout, Velocity, Acceleration includes direct measurement of velocity by use of a Doppler laser, and determines runout by integration of the velocity information while determining acceleration by differentiating the velocity information, with appropriate correction for sources of error. A menu driven system permits the user to select from a variety of options for testing of rotating objects and manipulation, storage and display of the data. A novel windowing technique permits the display of multiple child windows, each having its own set of pull down menus for use in connection with that child window.