Abstract: Data which is transmitted over the internet or other transmission networks is first divided up into individual information packets, transmitted and then reassembled into useful data after reception. Parity packets are included in with the information packets in the transmission of data in order to enable the regeneration of any information packets which were lost or damaged during transmission. The grouping of information packets and parity packets derived therefrom is termed a chunk. Chunk arrangements to recover from all cases of single and double lost packets are disclosed. Bursts of lost packets are recovered by interleaving the transmission of packets from different chunks. If the recovery is not successful then retransmission occurs in a manner similar to TCP.

Abstract: Data which is transmitted over the internet or other transmission networks is first divided up into individual information packets, transmitted and then reassembled into useful data after reception. Parity packets are included in with the information packets in the transmission of data in order to enable the regeneration of any information packets which were lost or damaged during transmission. The grouping of information packets and parity packets derived therefrom is termed a chunk. Chunk arrangements to recover from all cases of single and double lost packets are disclosed. Bursts of lost packets are recovered by interleaving the transmission of packets from different chunks.

Abstract: Data which is transmitted over the internet or other transmission networks is first divided up into individual information packets, transmitted and then reassembled into useful data after reception. Parity packets are included in with the information packets in the transmission of data in order to enable the regeneration of any information packets which were lost or damaged during transmission. The grouping of information packets and parity packets derived therefrom is termed a chunk. Chunk arrangements to recover from all cases of single and double lost packets are disclosed. Bursts of lost packets are recovered by interleaving the transmission of packets from different chunks. If the recovery is not successful then retransmission occurs in a manner similar to TCP.

Abstract: A touch screen system includes a touch screen having a surface which is adapted to be touched by a user, a resistive substrate which spans the screen and has two opposite boundaries, and a pair of electrodes which are capacitively coupled to the resistive substrate adjacent the two opposite boundaries thereof. The electrodes are adapted to be electrically stimulated from a source to induce reference electrical parameters within the system. Appropriate components are provided for determining changes in electrical parameters at the electrodes as a result of the touch of a location of the screen by the user, and associated componentry is also provided for generating a signal corresponding to the location of the screen touched by the user. The touch screen of the system may be associated with the screen of a CRT for use or placed upon a tabletop for use as a cursor control pad or a keyboard.

Abstract: An electrographic touch sensor of simplified construction having an increased proportion of area for providing linear output signals. The sensor utilizes a resistive layer of a substantially uniform resistivity throughout. A resistance element of resistance value borders and is in contact with the resistive layer. Positioned along a selected path proximate the resistance element borders are a plurality of insulator regions having a selected effective length along the path to define spaces of a selected effective length therebetween. These spaces, having the resistive layer therein, define resistive electrode elements by which voltages are applied from the resistance element borders into the resistive layer whereby orthogonal electrical fields can be generated in the resistive layer.

Abstract: A fiber optic coupling device for providing simultaneous bi-directional transmission of optical signals within a single wavelength band over a single fiber optic link cable, including a coupler/connector which precisely aligns and longitudinally separates transmit and receive lightguide fibers and a fiber optic link cable. The cores of the transmit and receive lightguide fibers are tightly aligned with a minimum thickness of cladding for increased packing efficiency, and the end faces of the transmit and receive lightguides are maintained parallel to and a predetermined distance from an end face of the fiber optic link cable to ensure that reflected signals will not be detected as received signals and allow simultaneous distinguishable bi-directional communication of optical data within a single wavelength band.

Abstract: A circular touch sensor having very linear response in a two coordinate system. This circular sensor has four substantially identical and symmetrical quadrants, with points for the introduction of potentials being located at polar and equatorial points on the sensor. The sensor has a uniform electrical sheet resistivity, and each quadrant has a resistance element to distribute the potentials to electrodes connected thereto which are positioned along the perimeter of the circular resistive surface. Individual ends of the resistance element in each quadrant are connected to their respective "tie points" through a resistor of a size to adjust for a proper resistance value between the quadrants at these points. The size (effective length along the position path) of the electrodes in each quadrant generally increases, and the spacing between electrodes generally decreases, symmetrically from the edges of each quadrant toward the center of that quadrant.

Abstract: A resistor electrode type touch sensor having enhanced area of linear response by reducing the bow in perimeters of the sensor. Within a resistive layer of substantially uniform resistivity orthogonal electrical fields are produced to give coordinates of a selected position. Overlying, but spaced from, the resistive layer is an optional flexible conductive pick-off sheet facing the resistive layer which will contact the resistive layer when touched at a selected position. Other elements are described to obtain signals corresponding to the coordinates of a selected point. A resistance element is positioned proximate the perimeter of the resistive layer made up of discontinuous conductive lines applied to the resistive layer. For a given value of the resistive layer, the value of the resistance element is determined by the length and width of any gaps between the conductive lines.

Abstract: An electrographic touch sensor having Z-axis capability. In one embodiment, a uniform resistive coating is applied to one surface of a substrate and it is within this coating that orthogonal electrical fields are produced using suitable electrodes and voltage applications to give coordinates of a selected position. Overlying the resistive coating is a flexible pickoff sheet having a conductive layer facing the combination. Interposed between the resistive coating and the conductive layer is an array of a material having a substantially greater resistivity than that of the resistive coating. Signals corresponding to the X- and Y-coordinates of a touched point on the sensor are obtained in a substantially conventional manner using an amplifier and an analog to digital converter. If desired, a Z-axis component signal due to pressure/force can be obtained in a separate part of the measuring cycle.

Abstract: A resistor electrode type touch sensor having enhanced area of linear response by reducing the bow in perimeters of the sensor and the method of accomplishing the same. A resistive coating is applied to one surface of a substrate. Within this coating orthogonal electrical fields are produced to give coordinates of a selected position. Overlying, but spaced from, the resistive coating is a flexible pick-off sheet having a conductive layer facing the resistive layer which will contact the resistive coating when the pick-off sheet is touched at a selected position. A resistance element is positioned proximate, but insulated from, the perimeter of the resistive coating. Electrodes of a selected effective length and spacing are located along selected paths proximate the edges of the resistive coating. Each electrode is attached to the resistive coating and connected to selected positions along the resistance element to provide selected voltages to the resistive coating.

Abstract: A fabric touch sensor for providing positional information related to a touched region/points. The improved electrographic touch sensor (10) is fabricated using at least one resistive fabric layer (12) in the form of conducting threads. This fabric is constructed using either unidirectional threads (16) or crossed threads (16, 18) formed by overlaying one set with another or weaving the two sets together. The fabric (12) is separated from a second resistive layer (14) to prevent unintentional contact, with separators (24) in the form of non-conducting threads (42), insulator dots (24), or with an air gap. In a preferred embodiment, both resistive layers are fabrics (12, 14) formed from conductive threads. Prevention of Moire-type visual patterns is achieved by orienting the threads in one fabric layer at an oblique angle to those of the second fabric layer.

Abstract: Apparatus is provided to size finely divided catalyst particles so that all of the catalyst particles passing through the apparatus are sized so as to have a maximum particle diameter. The apparatus includes:(a) A sealed cylindrical housing having an arcuate opening cut into its lower surface,(b) A fine mesh screen which overlaps the arcuate opening cut into the cylindrical housing,(c) A hemicylindrical housing attached to the lower surface of the cylindrical housing and defining a cavity in communication with the cylindrical housing,(d) An inlet port in the top center surface of the cylindrical housing,(e) An outlet port in the bottom center surface of the hemicylindrical housing,(f) A shaft rotating axially within the cylindrical housing and having brushes attached thereto which force catalyst particles from the cylindrical housing through the screen and break down catalyst agglomerates introduced into the cylindrical housing.

Abstract: An electrographic sensor for the generation of coordinate signals corresponding to contacted positions on the sensor is described. This sensor is of particular value for placing in intimate contact with the nonplanar face of a cathode ray tube or the like. The sensor has a rigid, optically transparent substrate with a nonplanar configuration matching the nonplanar face of the CRT to reduce parallax. This normally involves a radius of curvature, in one or more directions, in a range of 15-50 inches (38-127 cm). The surface of the substrate which will not contact the CRT is coated to provide a very uniform, substantially transparent, electrically resistive layer, and electrodes are connected to the resistive layer whereby orthogonal electrical potentials may be applied to the layer. Overlying and spaced from the resistive layer is a semirigid transparent cover sheet, the face toward the resistive layer being appreciably conducting.

Abstract: A data processing system having a principal apparatus, such as a programmable large-scale data processing system, and a secondary apparatus. The secondary apparatus performs fault detection and analysis on the principal apparatus. The secondary apparatus under control of a secondary program and independently from the principal apparatus, accesses information from different points, such as latch circuits, throughout the principal appartus. The accessed information is utilized by the secondary apparatus to form an actual checksum having a value determined by the accessed information. The actual checksum thus formed is compared with an expected checksum provided from storage by the secondary apparatus. If the actual and expected checksums are different, a fault condition is indicated. An analysis of selected subsets of points in the primary apparatus is made using a compacted scan composed of the values of the selected subset of points.