Abstract: A variable tracking word recognizer generates an indicating signal when a microprocessor has accessed a memory stack location storing a dynamically addressed variable, the address of the variable being the sum of a dynamically assigned base address of the memory stack and a known address offset where the variable is stored on the stack in relation to the base address. The variable tracking word recognizer stores the dynamically assigned base address, when determined by a space allocation subroutine of a program running on the microprocessor, and then monitors the addresses subsequently appearing on the microprocessor address bus, generating the indicating signal when the current address matches the combination of stored base address and known address offset.

Abstract: A method and apparatus are disclosed which provide for the generation of a trigger signal responsive to the detection of a plurality of selected sequential events in a single monitored signal. A plurality of trigger detect devices operate independently to monitor a signal for the occurrence of selected trigger criteria, and produce indications thereof having selected durations. The duration of the indications function to provide continuous indications of the occurrence of the selected trigger conditions over the periods thereof. In one embodiment, a state machine delays each of the indications by an amount of time approximately equal to the time between the respective events and a final event in the sequence, thereafter combining the indications according to preselected logical operations. As a result of the delays, the indications from the trigger detect devices are combined at approximately the same time.

Abstract: A differential transconductance amplifier includes two error amplifiers which provide an error correction current which linearizes a main differential amplifier. Two reference transistors coupled to the main differential amplifier provides two sets of input voltages to the two error correction amplifiers. The output currents of the main amplifier and the two error correction amplifiers are summed to produce a linearized output.

Abstract: A color image copying system (10) employs a cathode-ray tube (16) that employs a diffraction grating face plate (38) which for each image disperses to predetermined focal regions (132, 143, and 136) light rays of corresponding wavelengths. The light rays sequentially expose a region 80 of a scrolled light-sensitive medium (42) to form a composite color copy of the image. Bands of phosphorescent materials (32, 34, and 36) are applied on angularly inclined subregions (146, 148, and 150) of the inner surface (144) of the face plate and intercept a raster-scanned electron beam (22) to develop light of the different wavelengths. The inner surface of the face plate has angularly inclined subregions (146, 148, and 150) that provide for incident light rays of each wavelength an angular offset of equal magnitude but opposite rotational sense to compensate for changes in diffraction angles (.beta..sub.1, .beta..sub.2, and .beta..sub.

Abstract: An electron beam-addressed liquid crystal cell for a light valve. The cell (40) includes liquid crystal material (42) sandwiched between two substrates (16, 44). One substrate (44) is addressed by the electron beam (60a, 60b) and includes a coating (51) having a rate of secondary electron emission greater than the characteristic rate of secondary electron emissions of the base layer (49) of the substrate (44). The enhanced secondary electron emission characteristics of the coated substrate (44) permit the cell to be modulated with relatively lower electron beam current for correspondingly higher image resolution.

Abstract: An angle modulated periodic waveform is synthesized by generating three digital number sequences. In a first number sequence, one number thereof is generated on each occurrence of a periodic clock signal and has a magnitude which is a selected first periodic function of the number of prior occurring clock signals. In a second number sequence, one number thereof is generated on each occurrence of the clock signal and has a magnitude which is a selected second function of prior occurring numbers of the first number sequence and an applied constant carrier waveform frequency parameter. Each number of the second number sequence is added as it is generated to a stored second address number. In the third number sequence, one number thereof is generated on each occurrence of the clock signal and has a magnitude which is a selected third periodic function of the stored second address number.

Abstract: A measurement is carried out on a medium that propagates energy in a selected form by applying energy in the selected form to the medium, the power varying as a function of time in accordance with the elements of two Golay complementary sequences where one kind of element is represented by zero power and the other kind of element is represented by a predetermined non-zero power level and the successive elements of each sequence are applied at uniform intervals. Energy emitted from the medium in the selected form is received, and the variation as a function of time of the power emitted is correlated with the variation as a function of time of the power that was applied. Preferably, the level at which power is applied is varied both directly, in accordance with the elements of the two Golay complementary sequences, and in a derivative fashion, in accordance with the logical complements of the two Golay complementary sequences.

Abstract: A digital oscilloscope includes an amplifier having adjustable gain and offset for producing an output signal in response to an input signal, a triggering system for producing a trigger status signal when the amplifier output signal reaches an adjustable trigger level, and a digitizer for generating a waveform data sequence representing magnitudes of samples of the amplifier output signal acquired at various times with respect to assertion of the trigger status signal. The oscilloscope produces a waveform display on a screen according to the waveform data sequence produced by the digitizer and automatically adjusts the amplifier gain and offset, the trigger level, and the sampling rate of the digitizer so that the waveform data produced by the digitizer provides for a waveform display suitably representative of the time dependent behavior of the input signal.

Abstract: A visible representation of a colored image is created on a print-receiving area by resolving the colored image into p raster lines and resolving each raster line into q pixels, and creating a succession of sequences of digital words such that each word is associated with a pixel of the image and has one of n possible values, representing the color of the pixel. Consecutive words in each sequence of digital words are associated with adjacent pixels in a raster line of the image and consecutive sequences in the succession of sequences are associated with adjacent raster lines. First, for each of the n possible values of each digital word, a measure of the number of words that have that value is determined. Second, a set of the n possible values is selected, such that the number yielded in the first step for each value is not zero. Third, a subset of the selected set is identified such that pixels having the colors represented by the values in the subset do not appear adjacent each other in the image.

Abstract: In an oscilloscope, a readout control circuit is adapted to create a horizontal cursor on an oscilloscope screen at a vertical level controlled by cursor level data generated by a microcomputer, and to cause the beam to form characters on the screen indicating a voltage represented by the vertical level of the cursor. Vertical offset and vertical gain parameters characterizing a vertical preamplifier system controlling display of a waveform are measured and utilized to determine the value of cursor level data needed to cause the readout control circuit to position the cursor on the screen to accurately reflect a selected voltage with respect to voltage magnitudes represented by points on the displayed waveform.

Abstract: A contact device comprises a resiliently deformable member having two opposite surface regions, and strips of conductive material bonded to the deformable member at one of its two opposite surface regions. The strips of conductive material are of substantially uniform width, substantially parallel to each other and substantially uniformly spaced from each other. The width and spacing of the strips are less than the width and spacing of the terminal areas of the conductor runs that are to be connected by means of the contact device, so that each terminal area contacts at least two strips of the contact device.

Abstract: A frame buffer memory comprises a set of memory chips arranged in an array of n rows (planes) and m columns. All memory chips are identically addressed, a set of m, n-bit pixels being stored at each memory address with one bit of each pixel being stored in each array plane. Each memory chip of each column is row address strobed by a common row address strobe line while each memory chip of each plane is column address strobed by a common column address strobe line. By appropriately strobing selected row and column address lines, data may be written to the memory array on a pixel-by-pixel or plane-by-plane basis with such data being written to individual pixels or planes or to blocks of pixels or planes. Combinational logic within the frame buffer memory permits pixel data to be rapidly modified according to preselected rules during a memory write operation prior to being written into memory.

Abstract: An end portion of an elongate member of generally cylindrical form, such as an optical fiber, is placed in a predetermined position utilizing a substrate having a surface that is defined by a generatrix that is a straight line, e.g. a flat surface. A foil of flexible material is secured to the surface of the substrate and defines with the substrate a generally straight, elongate passageway that is parallel to the generatrix of the surface and has a first portion of substantially uniform cross-section adapted to receive an end of the elongate member in closely fitting relationship and also has a second portion that tapers towards the first portion. The end portion of the elongate member is inserted into the first portion of the passageway by way of the second portion thereof.

Abstract: A probe for coupling electrical test equipment to a selected point of an electrical device has a resiliently supported rigid pin for contacting the selected point and a wave guide of substantially constant characteristic impedance coupling the test equipment to the pin.

Abstract: A method for correlating video data between two video display formats uses a multi-function instrument which digitizes the input video data. An operator selects a horizontal line of the video data via a rotary encoder which updates a global variable common to all display formats. Subsequent selection of a different display format results in the same horizontal line of the video data being displayed in the new display format.

Abstract: A precision current generator provides an output current responsive to a reference supply voltage. The current generator comprises a voltage generator which drives the input to a buffer amplifier. The buffer amplifier output drives the bases of multiple output transistors, the collectors of which form the current outputs. The output current is not dependent upon transistor beta, junction voltage, temperature or supply voltage. The all NPN design enables the current generator to track the reference voltage at high frequencies without peaking or ringing of the output current and without voltage coupling between output devices.

Abstract: An asychronous state machine waits a variable length of time after first detecting a change in input state before initiating a machine state change, the new machine state being a function of the previous machine state and the input state at the end of the waiting time, thereby allowing multiple, non-simultaneous input changes to occur during said waiting time without initiating intermediate state changes. The waiting time is a function of the current state of the machine. One state variable of a set characterizing the current state of the machine indicates whether the current state is an interim state in a sequence of states occurring after an input state change. Following a machine state change, this sequencing state variable initiates a subsequent state change, in the absence of any further input state changes, when the sequencing state variable associated with the current machine state indicates that the current machine state is such an interim state of a sequence of states.

Abstract: A color image copying system (10) includes a light modulator (12) that receives incident light rays emanating from a source (14) of light. The light modulator comprises a light dispersing apparatus (54) that disperses different wavelengths of the incident light rays to different locations on a focal surface (60). A filter mask (68) aligned with the focal surface transmits preselected wavelengths of the ultraviolet light and blocks light of all other wavelengths. Each of a set of light valves (86, 88, 90) receives a different wavelength of light transmitted by the filter mask and intensity modulates it in accordance with image pixel information provided by an information source (16). An optical focusing apparatus (56) focuses the intensity-modulated wavelengths of light to a relatively small location (20) on an image focal surface (22) which is aligned with a light-sensitive medium (24).

Abstract: A variable transient response control for linear integrated-circuit high-frequency amplifiers comprises a variable equivalent resistive damping network interposed in the signal transmission path, and an electronic control circuit therefor. The resistive network includes preferably Schottky diodes having low inductance and a determinable equivalent resistance in the forward conducting condition.

Abstract: A charge-coupled device package comprises a substrate of dielectric material and a charge-coupled device die mounted on one main face of the substrate. The substrate is placed in heat exchange relationship with a cold sink, such as a bath of LN.sub.2. A temperature sensor senses the temperature at a location on the main face that is in close proximity ot the die. A film resistor is adhered to the opposite main face of the substrate and receives a current that depends upon the temperature sensed by the sensor.