Abstract: A printed circuit board for mounting in a housing, having a mounted connector for making connections with the circuit board through the housing includes a layer formed from electrically insulating material and a conductive structure formed on such layer which conductive structure is adapted to be connected to ground. A casing, also formed from electrically conductive material, is shaped to surround a portion of the connector and is electrically connected to the conductive structure so that electromagnetic radiation emanating from the circuit board will not pass through the connector. In embodiments where the connector is mounted on an edge of said circuit board, the casing surrounds all of but the open end of the connector. In a preferred embodiment the casing includes a top portion, connected to the conductive structure, for surrounding the top of the connector and a bottom portion, also connected to the conductive structure, for surrounding the bottom portion of the connector.

Abstract: A pump apparatus comprising an enclosure for holding a volume of fluid; an intake one-way valve for enabling intake of fluid into the enclosure; a discharge one-way valve for enabling discharge of fluid from the enclosure; a diaphragm for cyclically deflectably increasing and decreasing the volume of the enclosure whereby fluid is oscillatingly drawn into the enclosure and discharged therefrom; a heating assembly for selectively oscillatingly applying heat to the diaphragm and terminating application of heat thereto for selectively oscillatingly deflecting the diaphragm.

Abstract: A technique for decomposing any simple or complex arbitrary polygon into a trapezoid having at least one edge parallel to the scan direction for more efficient scan conversion by rasterization circuitry. An input polygon is split into "slabs", which are adjacent regions bounded by lines parallel to the scan direction. Initially the polygon is split at the y coordinate of every vertex to define the slabs. Then, for each slab, it is determined which edges are present in the slab and whether there are any unacceptable edge intersections. If an unacceptable edge intersection is found in a slab, that slab is broken into two or more slabs at the y coordinates of the intersection points of the edges. Each of the slabs is then processed independently. Once no unacceptable intersections are found in any slab, trapezoids are rendered from adjacent pairs of edges and sent to the rasterization circuitry.

Abstract: A method and apparatus for detecting errors in communicated data words irrespective of the order in which the data words are communicated.

Abstract: A scan-register having first and second data input ports (SYS.sub.-- DATA, SCAN.sub.-- IN), a data output port, and inputs for at least first, second, third, and fourth control signals (SYS.sub.-- CLK, M.sub.-- LOAD, CLK.sub.-- B, CLK.sub.-- A).

Abstract: A method for employing a hierarchical display list in global rendering comprises the steps of traversing the display list and extracting selected primitives and attributes. A bounding volume is defined for selected primitives, and data indicative of the selected primitives, attributes, and bounding volumes are stored in a global database. Global rendering may be performed by either ray tracing or radiosity based upon the data in the global database. In the event that global rendering is performed by radiosity, then a plurality of surface elements for each selected primitive is defined and also stored in the global data base. Shading attribute data for each of the surface elements is defined upon application of a radiosity rendering algorithm to the global database. An alternative display list may be defined from the global database, if desired.

Abstract: A valve apparatus for controlling fluid flow comprising a substrate having a first aperture extending therethrough for defining a first fluid flow path; a beam having first and second terminal end portions mounted in fixed relationship with the substrate and having a bucklingly displaceable intermediate portion positioned in overlying relationship with the aperture for covering and uncovering the aperture for preventing or enabling fluid flow through the aperture; and a temperature control assembly for selectively controlling the temperature of the beam for selectively bucklingly displacing the intermediate portion of the beam for controlling fluid flow through the aperture.

Abstract: An electronic component test procedure which can employ a combination of stress, test, and sort techniques useful for consolidating package test, burn-in test and qualification tests. The process can be automated to avoid batch process and virtually eliminate manual handling. Components are sorted according to initial values and mathematical stress models.

Abstract: A printed circuit board guide and support is disclosed which provides for mounting printed circuit boards into a housing while eliminating the need for screws or a complex housing design.

Abstract: Methods and apparatus for providing pixel brightness correction in monitors. The methods and apparatus disclosed herein provide significant cost reductions in gamma correction circuitry by first degamma correcting pixel value data stored on a frame buffer, and then gamma correcting the degamma corrected pixel value data before the data is stored back on the frame buffer. Circuits for providing pixel brightness correction in a monitor comprise logic circuits for generating upper bits of a data word representing pixel intensity, shifter circuits interfaced with the logic circuits for generating lower bits of the data word representing pixel intensity, and combining circuits interfaced with the logic circuits and the shifter circuits for generating intermediate bits of the data word representing pixel intensity.

Abstract: A formatter circuit for generating pulses of a variable, in particular extremely short width comprises an input terminal (10) receiving a pulse start signal which is fed to a frequency divider circuit (11) and another input terminal (12) receiving a pulse-stop signal which is fed to a second frequency divider circuit (13). One of these frequency divider circuits generates two internal signals which are fed to a multiplexing circuitry (16, 17, 18), whereas the other frequency divider circuit generates at least one signal which is the control signal for said multiplexing circuitry. (FIG. 3).

Abstract: An apparatus and method are disclosed for testing electrodeposition processes used in printed circuit board manufacture. The apparatus, having a photoresist pattern on a test printed circuit board, for use in a Hull Cell to determine efficiency, uniformity, and interactions of the process on the surface of the printed circuit board in order to provide for design rules and process specifications.

Abstract: Block pattern detection circuitry for the read subsystem of a streaming tape drive system comprises a state machine, a pattern decoder, a tape mark detector, a block/gap filter, a block/gap meter, a verify count section, and a block read/verify section. The incorporation of a hardware state machine within the block detect circuitry permits the application of historical detect data in the interpretation of present detect data. This provides more certain pattern recognitions. Also, state data is fed back to the block/gap filter allowing precise block boundary triggers which are used by position capture circuitry and the drive controller to effect more precise re-try positioning. The use of the block/gap filter increases the detect circuitry's immunity to noise. The advantage is enhanced where the block/gap filter uses stochastic thresholding, which is also advantageously employed by the tape mark detector.

Abstract: A nonlinear noninverting amplifier design for receiving and amplifying an input signal in an optical communication scheme having a nonlinear inverting feedback is disclosed. The inverting feedback varies nonlinearly with the input signal to avoid saturation of the amplifier while providing a zero state input amplitude signal to reduce the amplitude of the input signal required to turn-on the feedback, thus allowing the amplifier to operate with a wide variation of optical generators, paths, and converters. A nonlinear noninverting amplifier design is provided which eliminates the need for automatic gain control circuitry and can be designed as an integrated circuit.

Abstract: A method of calibration for a voltage to time converter in order to increment delays by a fraction of a clock cycle known as an interpolator period is disclosed. The method of calibration compares differences in measurements of a constant and repetitive input waveform while changing current, base voltage threshold, incremental voltage threshold, or any combination thereof to minimize the calibration error for a predetermined number of interpolator periods designed to equal an integral number of clock cycles.

Abstract: A tape driven system includes means for capturing data block boundaries while moving in reverse, as well as in the forward direction. Thus, block boundaries can be captured following each reversal of tape direction to cancel prior errors induced during tape reversals provided these errors are within tolerance. In a hitch operation, the rear boundary of a data block is recaptured as a reference position for the next forward operation. In a backspace operation, the front boundary of a data block is captured while the tape is moving in the reverse direction to provide a reference point for the next operation.

Abstract: An access door is described for a housing for tape drive apparatus of the type including a take-up reel, a hub for a supply reel, and a fan for moving air within the housing. The access door is hinged to the housing and is pivotable between open and closed positions. The access door includes an interior face which forms a ramp for guiding the supply reel into the housing and onto the hub. The door also includes an inlet port for receiving air from the fan, at least one exit port, and a passageway for communicating air between the inlet port and the exit port. Air leaving the exit port in the door is directed around the periphery of the supply reel.