Abstract: A user interface system and method for traversing a database. In one aspect the present invention includes providing a plurality of command options, each of the command options represented by a set of descriptive option index terms characterizing that command option. The set of descriptive option index terms characterizing the command options selected by a user, are compared with sets of document index terms. Each set of document index terms being compared characterizes an electronic document in a hypertext-type database which is selectively linked in that database with the user's present position. The comparisons result in a ranked list of the selectively linked electronic documents. The electronic documents are ranked in accordance with the relevancy of each document with respect to the selected command option.

Abstract: A method for fabricating liquid crystal shutters using a laser exposure system. An output beam from the laser is split into multiple exposure beams and a photoresist coated substrate having a metallic layer is caused to traverse the beams. The substrate is then processed leaving multiple parallel electrodes on the substrate surface.

Abstract: In a communication system including a plurality of networked stations that communicate using a slow frequency hopping system, a method for encoding a packet of data in a transmitting station and decoding the data in a receiving station. In the transmitting station, the packet is divided into data segments. Error correction segments are added to correct the data segments. The segments are fragmented into a series of fragments, and a data error control field is calculated for each fragment and appended thereto. The data units including the segments are transmitted, and in a receiving station all or a portion of the bursts are received. The DEC field for each received fragment is calculated and compared with the received DEC field to determine whether each fragment is good or bad. If there are a sufficient number of fragments in each column, then the data can be reconstructed.

Abstract: Text, graphics, or other selected objects of a computer screen are selected and converted into a "visual clipboard" which is attached to a convenient boundary of the screen. The visible clipboard is preferably implemented on a pen-based computer system where the object is selected by a stylus, is dragged to a boundary, and is converted to a clipboard icon at the boundary. Multiple clipboard icons may be produced by the user, and can be moved from one boundary location to another. The contents of the clipboard can be inserted or "pasted" into an application program by dragging the clipboard icon with the stylus to the desired insertion location. Preferably, each clipboard is provided with indicia representative of the contents of the clipboard.

Abstract: In circuitry which transfers data in streams in which a plurality of individual discrete groups of data are all addressed to the same address, apparatus for manipulating the data appearing in streams including a manipulation engine responsive to some portion of each group of the data transferred to cause the data to be manipulated in a particular manner.

Abstract: A method and apparatus for providing a correctly signed result of a linear interpolation (LIRP) function in a compute controlled display system. A correctly signed LIRP evaluation may be performed by simply adding a bias to each of the operands of the LIRP function and subtracting the bias to the result. Adding the bias is achieved by inverting the high (sign) bit of each of the operands. Subtracting the bias is achieved by inverting the high (sign) bit of the result.

Abstract: An interface device for a point-to-point connected serial bus in which bus clock and bus data transmissions on the bus cease between transmissions of packets of data, includes a low latency resynchronizing circuit and an end of packet detector which is independent of control data within the packet. The resynchronizer is based on an interface which receives bus data and bus clock from a transmission of a packet on the bus. A circular input buffer stores bus data received from the bus in data locations indicated by an input pointer in response to the bus clock. An input pointer generator supplies the input pointers to the input buffer in a circular sequence, beginning in a particular location during a first bus clock in a packet. An output selector supplies bus data from one of the N data locations in the input buffer to the selector output in response to an output pointer and in response to the local clock.

Abstract: A method and apparatus for demodulating a pulse width modulated (PWM) signal previously modulated with either a first or second data value comprises sensing an actual duration of the first period of the bit cell, and generating an actual first signal value that is proportional to the actual duration of the first period of the bit cell. Using the actual first signal value and an expected first signal value, a first adjustment amount is determined and used for adjusting the actual first signal value. Then, an actual duration of the second period of the bit cell is sensed. The adjusted actual first signal value is further adjusted by a second adjustment amount to produce a final adjusted signal value, the second adjustment amount being proportional to the actual duration of the second period of the bit cell. Finally, a signal is generated which alternatively has a first value or a second value in correspondence with the final adjusted signal alternatively being greater than or not greater than a reference value.

Abstract: A high quality stereophonic sound enclosure system high resolution intended for computer visual display monitors employing cathode ray tubes (CRTs) having a vertical aperture grill, and methods for construction of same. The aperture grill has a natural frequency centered within the musical scale. The stereo speaker system comprises a ported speaker enclosure within which are mounted two conventional cone speaker assemblies. A stereo audio amplifier and control unit for controlling the audio signals delivered to the speakers is mounted within the speaker enclosure. The speaker enclosure is internally mounted within the monitor with a minimum number of attachment members incorporating vibration isolation material to remove vibration components near the natural frequency of the aperture grill. The speaker enclosure is internally reinforced to reduce structural deformations which contribute to airborne transmitted vibration within the monitor housing when the speaker system is operating.

Abstract: An open-loop speaker amplifier and a dynamic range reduction circuit are disclosed. The speaker amplifier includes a bridge driver and a bridge circuit. The bridge circuit includes a first set of switches and a second set of switches. When the first set of switches are activated, a positive current flows through a speaker load. When the second set of switches are activated, a negative current flows through the speaker load. The bridge driver generates a pulse width modulated signal and a delayed pulse width modulated signal to drive the first and second set of switches of the bridge circuit responsive to a modulation signal. The modulation signal may be, for example, a plurality of pulse code modulated samples representing sound. The dynamic range reduction circuit modifies a selected signal to reduce the dynamic range of the sound reproduced based on the modulation signal. The selected signal is either the modulation signal or a reference signal.

Abstract: A polarizing fiber-optic layer for use within a liquid crystal multilayer structure, particularly for use in a computer system having a liquid crystal display screen. The invention relates to a specially designed thin polarizing fiber-optic layer which functions both as a polarizer of light in a specific direction and as a fiber-optic material for optically resolving an image to its surface from a position optically below the fiber-optic material layer. Using this double functioning material the problems of off axis viewing, contrast (and color) distortion and parallax can be solved in flat panel displays. This inventive layer replaces several complex layers of a conventional liquid crystal display thereby greatly simplifying display manufacture and improving performance.

Abstract: A computer controlled graphics display system that treats graphical objects in a uniform fashion for consistent, non-modal and direct manipulation of graphics objects. The user, by operating in a visual "point and click" fashion, may select a graphical object or shape and manipulate it in a number of ways without having to activate different modes for different manipulations. Possible manipulations include dragging, scaling, rotating and skewing. More than one shape can be selected and manipulated by compositing intersected shapes with a selection rectangle. The graphic manipulations are platform independent and thus are all carried out by directing the point and click tool.

Abstract: A circuit for reducing extremely low frequency (ELF) electric fields on cathode ray robe (CRT) devices comprises a power supply means, a CRT, a voltage sensing means, an amplification means, and a capacitive coupling within a feedback path to the CRT. A CRT anode voltage variation sensed by the voltage sensing means is amplified and inverted by the amplification means, producing a signal which is applied to the capacitive coupling within the feedback path. This signal modifies the impedance at the CRT anode, decreasing the voltage variation and thereby reducing ELF electric field magnitudes.

Abstract: A method and apparatus for generating perspective views of a scene. With a viewing position at the center of to be cylindrical environment map, different views can be obtained by rotating the viewing direction either horizontally or vertically. The horizontal construction method of the present invention generally involves the steps of: determining the portion of the cylindrical map to be viewed; vertically interpolating pixel values in the portion of the cylindrical map to be viewed and mapping to a viewing plane; and displaying the viewing plane. The vertical construction method of the present invention generally involves the steps of: determining the portion of the cylindrical map to be viewed; vertically interpolating pixel values in the portion of the cylindrical map robe viewed and mapping to a vertical plane; horizontally interpolating pixel values in the vertical plane and mapping to the viewing plane; and displaying the viewing plane.

Abstract: A node identification system is described for use in a computer system in which the various components of the system are interconnected via nodes on a communications bus. Once the topology of the nodes has been resolved into an acyclic directed graph, each node may be assigned a non-predetermined unique address. Each node having a plurality of ports has an apriori assigned priority for port selection. Each child node connected to a parent is allowed to respond in the predetermined sequence depending upon the port through which it is connected to its parent. Each node in the graph will announce its presence according to its location in the graph. Each receives an address incremented from the previous addresses assigned, thereby insuring uniqueness. The same mechanism may be implemented to allow each node in turn to broadcast information on the bus concerning the parameters of its local host.

Abstract: A modular enclosure for personal computer systems substantially comprises a 5-sided steel chassis, a plastic subassembly tray, a plastic detachable back panel, and a 4-sided plastic top cover including an integrally formed front panel. The internal subassembly tray comprises appropriately formed bays designed to receive various system subassemblies, each bay having an integrally formed subassembly retaining means to bear against and retain a subassembly placed in the bay. Top side and rear electromagnetic interference (EMI) shields are fitted and secured to the interior portions of the plastic topcover and rear panel so as to peripherally contact the chassis when the topcover and rear panel are installed. The internal subassembly tray is lowered into the interior region of the chassis and snapped into place at the front portion thereof. The rear panel is then positioned and secured to the chassis.

Abstract: An instruction mapping system comprises an instruction mapping circuit, a central processing unit (CPU), a data cache, and a memory. The address outputs of the CPU are coupled to a first address bus, while the address inputs of the data cache and memory are coupled to a second address bus. The instruction mapping circuit's address inputs are coupled to the first address bus, and the instruction mapping circuit's outputs are coupled to the second address bus. The CPU sends a pointer address via the first address bus to the instruction mapping circuit. The instruction mapping circuit determines whether the pointer address indicates that the next source instruction is within the subset of most frequently executed source instructions. If so, the instruction mapping circuit maps the pointer address to an address within the data cache. If not, the pointer address is routed through the instruction mapping circuit unchanged.

Abstract: An apparatus and method for imaging using context sensitive pixel modulation wherein a modulator dynamically examines the neighboring pixels to the current pixel being imaged and uses the neighboring pixel information in determining the specific modulation pattern for the current pixel.