Abstract: In a multicomputer, concurrent computing system having a plurality of computing nodes, this is a method and apparatus for routing message packets between the nodes.

Abstract: An improved communication system for the prevention of lockup in a computer system of the binary n-cube type. Input circuitry at each of the nodes is connected for receiving messages and includes an input buffer for initially receiving the messages. Output circuitry at each of the nodes is connected for transmitting holding the messages prior to and during transmission thereof. A kernel program at each of the nodes acts as an interface between the user process programs and exclusively controls the receiving and transmitting of messages into and out of the node. There is provision for the user process programs to pass control to the kernel program to request the sending and receiving of messages by the kernel program. A lock bit is associated with each message, sensible by the user process programs, and reset by the kernel program when the kernel program has transferred the associated message.

Abstract: A method and associated apparatus for accessing a plurality of DRAMs in the static column mode by a high performance instruction processor to provide minimum wait state accessing thereby.

Abstract: A deadlock-free routing system for a plurality of computers ("nodes") is disclosed wherein each physical communication channel in a unidirectional multi-cycle network is split into a group of virtual channels, each channel of which has its own queue, one at each end. Packets of information traversing the same physical channel are assigned a priority as a function of the channel on which a packet arrives and the node to which the packet is destined. The packet's priority is always increasing as it moves closer and closer to its destination. Instead of reading an entire packet into an intermediate processing node before starting transmission to the next node, the routing of this invention forwards every flow control unit (flit) of the packet to the next node as soon as it arrives. The system's network is represented as a dependency graph, which graph is re-ordered to be cycle free.

Abstract: A digital video display system wherein the various characters to be displayed are displayed in the form of images of the complete character rather than the standard dot-matrix pattern of the prior art. A character generator in the display system stores signals representing the various characters to be displayed which are retrieved from storage in response to a character code. The signals are in the form of a binary code having a sufficient number of bits to represent a different number of levels of gray-scale or luminance values for the various picture elements making up the character image. The binary codes thus retrieved from storage are supplied to a video synthesizer that generates the video signal to display the character images which may be displayed in a number of different modes including white-on-black, black-on-white, black-on-gray, and white-on-gray as well as different combinations of such modes to represent a cursor.

Abstract: This disclosure relates to a color video system that is adapted to receive digital codes representing values of different colors that are to be displayed to create an image on a standard video monitor. The system employs a video synthesizer which includes a memory in which appropriate digital signals are stored representing the desired transformations of the signals to signals that are to be transmitted to the video monitor. Specifically, the system is adapted to transform respective color codes to codes required for the I, Q, and Y mode of transmission.

Abstract: This disclosure relates to a digital video display system wherein a control element is provided that includes position and count registers to specify the initial position of a scan line and the number of scan lines displayed which registers are supplied with incoming data to specify the position of each character line so that the position of a character image on display can be adjusted upwardly or downwardly to give the appearance of smooth scrolling.The various characters to be displayed are displayed in the form of images of the complete character rather than the standard dot-matrix pattern of the prior art. A character generator in the display system stores signals representing the various characters to be displayed which are retrieved from storage in response to a character code. The signals are in the form of a binary code having a sufficient number of bits to represent a different number of levels of gray-scale or luminance values for the various picture elements making up the character image.

Abstract: An apparatus and method are described for applying a light beam in an extremely precise pattern to a work piece, such as a photographic plate or reticle on which an integrated circuit pattern is to be formed and which will be then utilized to produce integrated circuits. The method includes moving a very narrow beam light source relative to the reticle in a scanning pattern such as an X-Y raster pattern, accurately sensing the relative positions of the light source to the reticle as by the use of laser interferometers, and briefly energizing the light source only when it lies at the locations to be exposed. The light source is energized while it moves, so it is not necessary to stop the light source at precisely located positions.

Abstract: This disclosure relates to a digital video display system wherein the various characters to be displayed are displayed in the form of images of the complete character rather than the standard dot-matrix pattern of the prior art. A character generator in the display system stores signals representing the various characters to be displayed which are retrieved from storage in response to a character code. The signals are in the form of a binary code having a sufficient number of bits to represent a different number of levels of gray-scale or luminance values for the various picture elements making up the character image. The binary codes thus retrieved from storage are supplied to a video synthesizer that generates the video signal to display the character images which may be displayed in a number of different modes including white-on-black, black-on-white, black-on-gray, and white-on-gray as well as different combinations of such modes to represent a cursor.

Abstract: An I/O data interface provides an access mechanism without requiring additional lines on the bus for device address presentation for the request of access. Each peripheral device can detect an invitation-to-request access signal and in response thereto, to supply its own device address on the bus in a serial manner with any other device requesting access. Respective device addresses are assigned to respective peripheral devices in accordance with their priority, the higher priority devices having a higher address and the lower priority devices having a lower address. If any address bit of a particular device is lower than an address bit on the bus, the device ceases to supply its address bits with the result that only the requesting device having the larger device address will be selected for communication over the I/O bus.

Abstract: An asynchronous system includes a plurality of cascaded asynchronous cells in which data is transferred through the system according to the presence of data in the cells. Each cell contains two latches for storing binary data. Means are provided for feeding back to the previous cell a signal indicative of data stored in either of the latches. Transfer gate means cooperating with the latches and the feedback data presence signal provides a means by which data is sequentially transferred through the queue according to the presence or absence of data in the cells.