Abstract: An application specific integrated circuit is disclosed for use with a device locatable on a serial data bus of a data communication system. Attention and synch receiving circuitry is provided for receiving an attention and synch signal being transmitted on the serial data bus for synchronizing the device in accordance with the timing of the attention and synch signals. Demodulation circuitry is provided for receiving a command byte signal and a stop bit signal being transmitted on the serial data bus. Demodulation circuitry is provided for demodulating the command byte signal. Reset circuitry is coupled to the demodulation circuitry for receiving the command byte signal if the command byte signal contains a predetermined reset code. Flush circuitry is coupled to the demodulation circuitry for receiving the command byte signal if that signal contains a predetermined flush code. The flush circuitry clears all device specific data in the integrated circuit in response to the predetermined flush code.

Abstract: An optically transmissive armature is presented for use with an optical encoder mechanism in a cursor control device. The armature includes a substantially planar rectangular base, a plurality of supports, and a plurality of optical wave guides. An encoder mechanism is rotatably secured to the supports by an axis and is disposed in a predetermined position between the wave guides. The guides provide an optical pathway between photo-emitter/photo-detector pairs mounted on the surface of the printed circuit board of the cursor control device.

Abstract: A power manager within a portable laptop computer provides power and clocking control to various units within the computer in order to conserve battery power. Transistor switches controlled by the power manager control the distribution of power and/or clock signals to the various units within the computer. The power manager includes a software routine for continually monitoring the various units and when these units are either not needed and/or not currently in use, power and/or clock signals are removed from a given unit.

Abstract: A computer system interconnection including a plurality of nodes each such node being associated with at least one of a plurality of computer system components. Transmission apparatus connects each of said nodes to a node which is a source of information and to a node which is a recipient of information. Each of such nodes comprises apparatus for storing information, apparatus for receiving information from and transferring information to the associated one of the system components, and apparatus for placing a voucher signal on the transmission apparatus in response to the receipt of information from the associated one of such components to indicate that the node has information to be transmitted to another system component.

Abstract: An electrical conductor that electrically couples a circuit board to another electrical device. The connector has a flexible circuit board with at least one electrical conductor that is attached to a flexible dielectric sheet. Attached to the electrical conductor is an electrically conductive elastomer adapted to engage conductive pads on the surface of the circuit board. The connector has a plate or other member that presses the conductive elastomer onto the conductive surface pads, creating an electrical path between the conductor and the circuit board. The conductor is attached to the electrical device, wherein the electrical device is electrically coupled to the circuit board.

Abstract: In an improved computer system ring interconnection including a plurality of nodes such nodes being connected by transmission apparatus to a source node of information and a recipient node of information and being associated with at least one of a plurality of computer system components; in which each of such nodes includes information receive and transmit apparatus to and from the associated system component(s) including voucher signal placing apparatus indicating internodal information for transfer, voucher signal receive apparatus determining ability to receive, ticket signal placing apparatus indicating ability to receive information associated with voucher; apparatus to relay information to other nodes; internodal relay apparatus for tickets and vouchers; and information selection apparatus depending on urgency status including apparatus for storing information originated from component and information from other nodes to other nodes based on urgency level, and apparatus for selecting of this information

Abstract: A collapsible keyboard for use with portable personal computers is disclosed. A first preferred embodiment of the present invention comprises a keyboard molded from a conductive, elastomeric material and a collapsible frame/circuit board substrate, the substrate having a plurality of electrical contacts to indicate to the computer when a key is pressed. As the keyboard is formed from an elastic material, it can be compressed into a first, closed position of minimum size to facilitate carrying the computer and to minimize the computer's size. In the keyboard's second, expanded position, each of the molded keys overlies a pair of contacts. When a key is pressed while the keyboard is in this second position, an electrical circuit is formed by the key and the contacts, indicating to the computer both that a key has been pressed and which key has been pressed.

Abstract: An apparatus and method for taking data that is presented on a NUBUS in NUBUS format and writing it into a video memory in chunky planar format, is described. The present invention is also useful for performing RGB reads wherein video data is read from the video memory in chunky planar format and is translated into NUBUS format for transmission across the NUBUS. The apparatus comprises a data format translator which is coupled to the NUBUS for translating the RGB data from NUBUS format to chunky planar format. The translated RGB data in chunky planar format is compressed and rearranged as compared to the NUBUS format--resulting in a more efficient utilization of video memory space. An address generator is also coupled to the video memory for calculating the address location in the video memory where the translated RGB data is to be written. The address location is derived from the NUBUS address according to the formula N.sub.start =(3*NAD/4) where N.sub.

Abstract: A pattern recognition system having inter-pattern spacing correction is disclosed which recognizes words and determines where to place spaces between those words by (a) storing each input character in one or more buffers in memory, (b) comparing the last entry of each buffer against a dictionary of known words, (c) copying last entries which match words to new buffers and placing a space after the last entry in the old buffer, (d) deleting a buffer when a last entry from that buffer does not at least match the beginning of a known word in the dictionary, (e) repeating steps (a) through (d) until all the buffers have been deleted or until an end character, such as a carriage return or period has been stored in each buffer, (f) again comparing the last entries from each buffer to the dictionary and deleting any buffer having a last entry which is not a known word in the dictionary or which does not end with a space followed by an end character, and (g) saving and/or outputting the remaining words.

Abstract: In a computer system with a raster output device, a method for manipulating the outlines of a symbol image at various sizes such that the outline defines a close representation of the symbol image. A plurality of control points which correspond to an outline of the symbol image are stored in a memory of the computer system. The size of the symbol image which is to be output on the raster device is determined. The computer system then determines, given the size of the symbol image, whether the control points of the outline of the symbol must be adjusted in order to provide a proper display of the symbol. If adjustment is warranted, at least one of the control points for the outline is selected. The selected control points are then displaced by a predetermined amount to form a new outline of the symbol image. This adjusted outline is then stored in the computer system's memory and may be output in the raster device.

Abstract: A logic cell is described having four inputs, four outputs, a control store, means for multiplexing the four inputs onto two leads and logic means that operate in response to the signals on the two leads and signals from the control store to produce output signals which are applied to the four outputs. Illustrative logic functions provided by the logic means include a cross-over or identify function, a change in the routing direction of an input signal, NAND and XOR gates and a D-type flip-flop. The selection of two of the four inputs as well as the selection of the particular logic function that is implemented is controlled by control bits stored in the control store. Numerous such logic cells are arranged in a two-dimensional matrix such that each cell has four nearest neighbor cells, one to its left (or to the West) one to its right (or to the East), one above it (or to the North) and one below it (or to the South).

Abstract: A method for manipulating the control points of a symbol image represented by an outline font to improve the appearance of the font on raster output devices which are under control of a computer. The method includes storing control points specifying the outlines of a symbol image, specifying the desired movement direction defined by a first unit vector in which the control point should move, and specifying a desired measurement direction defined by a second unit vector by which the movement of the control point should be measured. The desired measurement direction and the desired movement direction forming an angle of predetermined size. The method further includes moving the control points in the desired movement direction and measuring the control points against the predetermined angle with the desired measurement direction, this measurement producing a resulting movement direction and storing the results of the manipulation of the control points in a memory.

Abstract: The invented controller uses a programmable parameter scheme which makes it possible to read and write 3 1/2 inch variable and fixed speed drives, as well as standard 5 1/4 inch drives. Additionally, the present invention uses a plus/minus rate multiplier to correct for symmetry and frequency errors. Also provided is a form of read post compensation which corrects for peak shift effects on disks with insufficient precompensation. Other advanced features of the present invention include the use of half clock circuits to provide half clock resolution in the signal being written to and read from the disk and the capability of operating at continuously variable clock speeds and data rates dynamically programmable by the computer.

Abstract: A computer which provides a video signal for display is disclosed. The computer has a central processing unit (CPU) which executes a program to provide video data for a display which is organized as a matrix of pixel elements, each pixel element being represented by a certain number of bits of video data stored within a random-access memory (RAM) in the computer. A video integrated circuit is coupled to the RAM to provide N bits of video data per pixel to the display at a dot clock rate consistent with the requirements of the display. This video circuit, rather than having its own video RAM, shares the system memory (i.e., RAM) with the CPU. A memory controller arbitrates access to the RAM between the CPU and the video circuit in a manner that denies access to the RAM by the CPU whenever the video circuit is reading video data from the RAM.

Abstract: An electric field cancellation system and method for reducing electric fields are presented, especially suited for use in reducing the magnitude of electric field emissions from a CRT display. Signals from the electric field sources of the display are used to generate counter signals of equal magnitude and opposite polarity to the source signals. These counter signals are coupled to a plurality of transmitters which effectively establish a counter electric field, or fields, of opposite polarity to the source fields. The net effect is substantial reduction in the electric field emissions from the display, and a resultant electric field of substantially reduced magnitude encountered by a display operator.

Abstract: Method used by a first entity, typically a computer system, on a communication system for assigning itself a unique address known as a network address, which comprises a network number and a node identification number. The entity determines a unique network address for itself within a local subset of entities known as a local area network (LAN). A signal is then transmitted to determine whether a router is connected to the LAN, and if so, to determine if the network number of the address is within a range allowed by the router. If the network number is not within a range allowed by the router, then another network number is selected from a range of numbers provided by the router and another node ID are selected. It is determined whether this value is being used by any other entities in the LAN, and if so, node ID's are selected until an unused network address is ascertained.

Abstract: An external digital phase locked loop for use in connection with a conventional serial communication controller is driven by a clock whose frequency is ten times the nominal data rate. Bit cells are divided into ten contiguous states. An adjustment window encompasses two states on either side of the nominal bit cell boundary. If a data transition is detected in either of two states later than the cell boundary, the bit cell timing is extended by one full state. On the other hand, if a data transition is detected in either of two states earlier than the nominal bit cell boundary, the bit cell timing is decreased by one full state.

Abstract: A method for changing the orientation of a graphic object in response to changes in the variable position of that object on the display of a computer is disclosed. The position of the graphic object on the display is determined by the position of a control point having a fixed position in relation to the object and a variable position in relation to the display. The control point is operative to change its position in response to translational signals received by an interactive control device, and the computer is operative to display the object at each position of the control point. A change in the orientation of the object to be displayed at the new position of the control point is determined by establishing a following point having a fixed position with respect to the object and a variable position with respect to the display, and tracking the variable position of the following point behind the path of the motion of the control point.

Abstract: A modular keyboard apparatus allowing users to reconfigure the keyboard for their particular applications and convenience. The modular keyboard allows the user to place modules such as alphanumeric keypads, numeric keypads and trackballs into the keyboard housing in positions which are most convenient to the user and to the applications being used. The keyboard can be reconfigured with, for example, a numeric keypad on the right hand side for a right handed user and the numeric keypad on the left hand side for a left handed user. Another example would allow the keyboard to be configured with a trackball assembly instead of the numeric keypad for applications which benefit from use of the trackball over use of the numeric keypad. Apparatus for coupling the various input devices with the keyboard housing assembly are disclosed.