Abstract: A CCD is fabricated from an intermediate product comprising a body of semiconductor material having a channel region of a first conductivity type bounded by a substrate region of a second, opposite conductivity type and a surface of the body, and first and second gates overlying the surface and spaced from each other. The method comprises introducing a dopant into the channel region by way of the surface of the body. The first and second gates are opaque with respect to the dopant. The dopant is such that it forms a zone within the channel region, beneath the space between the first and second gates, and the zone is of the first conductivity type and is of a higher doping concentration than other portions of the channel region. A third gate is formed over the surface of the body of semiconductor material, the third gate being at least partially disposed across the space between the first and second gates.

Abstract: A sequence controller includes a plurality of time slice modules, each producing an adjustable number of sequentially asserted time slice signals, and a plurality of phase generators each having as input the time slice signals produced by an associated one of the time slice modules. Each phase generator produces a square wave output signal, the timing of the rising and trailing edges of each pulse thereof being determined by a selectable pair of its input time slice signals. A state machine monitors time slice signals produced by the time slice modules and transmits a separate enable signal to each time slice generator in response to the time slice signals. Each of the time slice modules produces time slice signals only when output enabled by an enable signal from the state machine.

Abstract: An improved graphics display system includes a picture processor for processing display lists defining graphic designs, the display lists comprising pixel data and/or instructions for generating pixel data. The system further includes a display controller which stores pixel data in a frame buffer memory and controls a display of graphic designs in accordance therewith. When a display list defining a graphic design is changed but the design is not to be displayed, the display list is processed by the picture processor, but the output pixel data generated by the picture processor is routed not to the display controller but to a control processor which stores the generated pixel data in a second memory. When the design is thereafter to be displayed, the control processor generates a secondary display list including the pixel data stored in the second memory to the picture processor.

Abstract: A programmable counter or timer is preloaded with a value that serves to discriminate between meaningful transitions and spurious ones, and an output latch is initialized so that the value it contains is equal to the initial value of a comparator output. The binary output of the comparator is then continuously compared with the content of the output latch. If the two values become unequal, indicating a change in the state of the comparator output, the timer or counter is enabled to start timing or counting. If the change in the comparator output lasts long enough to qualify the transition as meaningful, the timer/counter times out clocking the new comparator output condition into the output latch.

Abstract: A computer terminal work station having multiple peripheral units simultaneously interconnected into the terminal. A micro processor controller is provided in the terminal and a micro processor slave is provided in each of the peripheral units. Each unit is provided with a bus segment and means to interconnect the bus segments to each other. A single cable extends from the terminal to one of the peripheral units to be connected to the bus segment of that unit, and thereby to the bus segments of all the interconnected units. The units are selectively mechanically interlocked as desired.

Abstract: An electronic delay control circuit provides small, constantly variable delays to an input pulse signal without altering the pulse width of the input signal. The input pulse signal together with a first reference signal are input to three comparators in parallel. The output of one comparator is a pulse signal corresponding to the input pulse signal, and the outputs of the other two comparators are tied together and input to a pulse shaping network to produce delay current pulses for the leading and trailing edges of the input pulse signal. The delay current pulses are added to the output pulse signal to produce a delayed output pulse signal. The delay current pulses are a function of the amount of a constant current steered between the two comparators as determined by a delay control signal.

Abstract: An apparatus for generating a CMOS comparator bias voltage for a CMOS comparator includes a dummy comparator having a negative input and a positive input coupled together to receive a common mode reference voltage corresponding to the common mode input voltage of the CMOS comparator. The dummy comparator also includes a bias input and an output. The apparatus for generating a CMOS comparator bias voltage further includes a bias amplifier having a negative input coupled to the output of the dummy comparator, a positive input for receiving a threshold reference voltage corresponding to the input threshold of the next stage driven by the CMOS comparator, and an output coupled to the bias input of said dummy comparator to form a comparator bias voltage.

Abstract: A user interface for a tester or simulator includes a menu for creating templates. The templates organize a set of the user's decisions regarding the timing, direction, and masking of all of the signals occurring during one tester cycle into a convenient form for use in another menu where test vectors are actually specified. In this other menu, the templates serve as a shorthand way of describing the function of each channel and its timing characteristics during one tester cycle. Thus, these templates organize and simplify the user's decision making, since many decisions, that would otherwise have to be made again and again, may now be made only once and then incorporated again and again by reference to the appropriate template. The use of the templates also conserves total memory requirements. The template menu can provide visual feedback that includes timing diagrams and icons to assist the user in constructing the template.

Abstract: A device for rendering a data source compatible with a processor having a predetermined protocol for receiving information from peripheral devices, comprises a controller for receiving information from the data source and conducting the protocol with the processor to place the processor in a condition for receiving the information. A latch receives information from the controller and makes the information available to the processor when the processor is in a condition for receiving information.

Abstract: A combined electrical and optical channel for use in an oscilloscope is provided in which the vertical deflection factor is set by a single input attenutation selector switch. The electical input is passed through an attenuator. The optical input is passed through an input transimpedance amplifier having at least two gain modes and an attenuator. The output from the input attenuation selector switch is encoded to form a digital output. The attenuators for the electrical channel are driven directly by the input attenuation selector switch or by the digital output corresponding to the setting of the input attenuation selector switch. The digital output is also decoded by a logic block to generate a gain mode logic signal to switch the gain modes of the input transimpedance amplifier.

Abstract: A circuit board is fabricated from a substrate of dielectric material having at least one run of conductive material adhered to one surface thereof. A second substrate of dielectric material is bonded to the one surface of the first substrate so as to cover the run of conductive material. A hole is formed through the first and second substrates and intercepts the run of conductive material. Conductive material is introduced into the hole and establishes electrically conductive contact with the run of conductive material. The diameter of the hole is at least as great as the width of the run of conductive material where it is intercepted by the hole.

Abstract: A circuit board ejector/guide has an ejector end and an integral guide end. The ejector end has a first bearing surface and the guide end adjacent the ejector end has a second bearing surface. The ejector end has means for pivotally mounting the circuit board ejector/guide on an extender circuit board so that the first bearing surface is used to remove the extender circuit board from a housing when the circuit board ejector/guide is in a stored position. The guide end includes guide rails for holding a circuit board to be tested when in an open position, and the second bearing surface is used to remove the extender circuit board from the housing when in the open position.

Abstract: A circuit for detecting positive and negative pulses of a predetermined maximum duration of an input signal includes a first monostable circuit for generating a first pulse having a duration equal to the predetermined maximum duration when a positive-going edge of a pulse occurs in the input signal. A second monostable circuit is provided for generating a second pulse also having a duration equal to the predetermined maximum duration when a negative-going edge of a pulse occurs in the input signal. An AND gate is coupled to the output of the first and second monostable circuits for generating a signal having a third pulse equal to the period of time both of the first and second pulses occur simultaneously. A flip-flop is coupled to the output of the AND gate for generating an output signal of a first logic state when the third pulse is generated.

Abstract: A method and apparatus for determining the effective bits of resolution of a digitizer wherein amplitude, frequency, phase angle and offset parameters characterizing a sinewave input signal to the digitizer are estimated from the waveform data sequence produced by the digitizer in response to the input signal. These estimated parameters are used to develop a model of the sinewave signal, and the effective bits of resolution of the digitizer are then determined by the comparing measured magnitudes of the sinewave signal as represented by the waveform data sequence to estimated magnitudes of the input signal being determined from the model.

Abstract: A matrix display drive circuit is disclosed which generates multilevel and multiphase, time-variant drive waveforms for driving the rows and columns of a ferrolectric liquid crystal matrix display. The circuit can provide up (write) and down (erase) pulses selectively to each pixel of the display using standard twisted-nematic type liquid crystal display drivers. A complex waveform generator provides multilevel, multiphase control signals to the supply voltage inputs of the drivers. Timing and synchronizing signals are extracted from the graphics data and timing source outputs to allow such multilevel, multiphase signals as may be required for the effective multiplexing of the display matrix.

Abstract: An oscilloscope automatically measures an interval between first and second triggering events in a repetitive input signal. The oscilloscope includes A and B sweep circuits for generating event triggered "A" and "B" sweep ramps, respectively. The oscilloscope also includes two comparators. One comparator generates an "A" indicating signal when the A sweep ramp reaches the level of a first adjustable reference signal. The other comparator generates a "B" indicating signal when the B sweep ramp reaches the level of a second adjustable reference signal. The oscilloscope initially sets both sweep circuits to repetitively trigger on the first event and sets the first reference signal to a constant level. While monitoring relative timing of the A and B indicating signals, the oscilloscope iteratively adjusts the second reference signal to a "first pass" level for which the A and B indicating signals are repetitively generated at substantially similar times.

Abstract: An electronic circuit is tested by applying a sequence of test vectors to the input port of the circuit as a plurality of sub-sequences each including at least one test vector. Serial scan vectors provided at a serial scan port of the circuit are examined after each sub-sequence, and determination is made as to whether a part of the serial scan vector indicates the presence of a defect in the circuit. In the event that a part of the serial scan vector indicates the presence of a defect in the circuit, information that identifies the number of serial scan vectors that have previously been examined and the part of the serial scan vector that indicates the presence of a defect in the circuit is made available for analysis.

Abstract: A matrixed display device comprises a plurality of monochrome optical bodies arranged in a matrix of intersecting horizontal rows and vertical columns and an optical bandpass filter element associated with each such body. The filter elements are in first, second and third arrays, passing red light, green light and blue light respectively. In each row and column of the matrix, a filter element of one of the three arrays is located between filter elements of the other two arrays. With this arrangement of filter elements, a color pixel can be formed by selectively stimulating first and second monochrome optical bodies that are adjacent each other in a first row of the matrix and a third monochrome optical body that is in a row adjacent the first row and is in the same column as one of the first and second optical bodies.

Abstract: A multiple beam cathode-ray tube employs a bipotential electrode structure to provide acceleration and convergence of the electron beams without the use of a resistive helix coil. In a preferred embodiment, the bipotential electrode structure (10) is employed in a cathode-ray tube (14) in which a cathode (28) and a grid electrode structure (30) cooperate to form plural beams of high velocity electrons. The bipotential electrode structure includes an immersion lens cylinder (16) that is positioned upstream of a tubular electrode element (18). The outer diameter (226) of the immersion lens cylinder is less than the inner diameter (228) of the tubular electrode element, thereby allowing the downstream end of the immersion lens cylinder to extend into the upstream end of the tubular electrode element. A potential difference applied between the immersion lens cylinder and the tubular electrode element accelerates the electrons in the multiple beams and converges them to form an array of crossovers at a plane (64).

Abstract: A rotary pulse generator is disclosed which generally includes a wheel rotatable about an axis. The wheel has a plurality of protrusions which deflect a piezoelectric element in a deflection zone. Several embodiments are shown. The various features include a thumbwheel in which the turning surface has teeth on it serving as the protrusions, a thumbwheel in which the teeth are directed radially inwardly, a push/pull knob which places the wheel in alignment with a selected one of three piezoelectric elements, and a wheel held in selected positions by an indent/detent mechanism with rods extending out of the side of the wheel to deflect the piezoelectric element. Yet another embodiment provides for the combination of linear and rotary pulse generation. Another form provides four sets of indicator locations with a location from each of the sets forming an aligned row of indicator locations.