Abstract: A multipurpose keyswitch for controlling cursor movement on a CRT display and for character entry includes a key cap that moves laterally to provide cursor control and that moves vertically for character entry. Sensors are coupled to the key cap for sensing the lateral movement of the key cap. Forward and backward movement of the key cap selects upward and downward movement of the cursor on the CRT display. Left and right movement of the key cap selects left and right movement of the cursor. Vertical movement of the key cap selects the entry of a character. The multipurpose keyswitch is advantageously positioned as one of the home keys of the keyboard.

Abstract: A self aligned, nonoverlapping gate structure for a charge coupled device is fabricated by depositing three sets of interleaved polysilicon gate electrodes. The first set of electrodes is applied in a planar form and sized to a width of about one-third the spacing of the electrodes of the first set. The second and third sets of electrodes are applied to overlap, in turn, portions of the previously applied electrodes. A thick shield layer of SiO.sub.2 is deposited and patterned atop the first and second sets of gate electrodes. After deposition of the third set of electrodes, the shield layers are removed to provide passageways extending beneath the overlapping portions of the second and third sets of electrodes. Such overlapping portions are then removed by etching through the passageways, to produce a nonoverlapping, generally planar gate structure.

Abstract: An equivalent time pseudorandom sampling system samples a repetitive waveform within each of several narrow acquisition windows bounding repetitive sections of the waveform in order to obtain equivalent time sample data characterizing the shape of the waveform included within the acquisition windows. The period between successive triggering events is measured and sampling is delayed following an initiating triggering event by delay time adjusted according to the measured period so as to maximize the probability that sampling will occur within an acquisition window. The time difference between samples and subsequent triggering event is measured with high accuracy and resolution utilizing a time interval measurement system based on a dual vernier interpolation.

Abstract: A waveform monitor for television has dual video channels displayed simultaneously side-by-side. The two channels are synchronized with each other or with an external sync signal and are input to a multiplexer prior to the display. A microprocessor controls the switching of the multiplexer according to the selection made by an operator. The first channel is displayed during the first half of the horizontal display sweep, and the second channel is displayed during the second half, the horizontal sweep encompassing two horizontal lines of video.

Abstract: A method for adjusting a time delay of a signal with respect to a reference event is achieved by displaying a graphical representation of the delay time on a display terminal, modifying the displayed graphical depiction to indicate a different time delay, and then adjusting the time delay of the signal to match the modified time delay indicated by the displayed graphical depiction. The display terminal is controlled by a display controller and the graphical depiction of the delay time is modified by an operator using cursor control keys of a keyboard to transmit a first indicating signal to the display controller and other keys of the keyboard to transmit a second indicating signal to the display controller. Each time the controller detects a first indicating signal, the graphically displayed delay time is incremented and each time the controller detects a second indicating signal, the graphically displayed delay time is decremented.

Abstract: A digital phase shifter uses a heterodyne concept to mix a continuous wave (cw) signal with a local oscillator which is an integer multiple of the difference frequency. The difference frequency is phase-locked, and the local oscillator frequency is divided into N increments by a counter. The count of the counter is compared to a microprocessor generated phase shift value which is added to the difference frequency. The phase shifted difference frequency is then converted up to produce the phase shifted continuous wave signal.

Abstract: Alignment is established between a member that defines an optical path and a semiconductor device that, when electrically biased, emits light in a predetermined direction, so as to establish an optically coupled relationship between the member and the device, by passing light along the optical path in a direction towards the semiconductor device, so that light is incident on the semiconductor device. An electrical characteristic of the semiconductor device is observed, and relative movement between the member and the device is brought about until the electrical characteristic indicates a desired degree of optical coupling between the member and the device, and the device and the member are then mechanically coupled together.

Abstract: The cathode-ray-tube beam deflection of an oscilloscope is automatically calibrated by photoelectrically detecting the intersection of the tube's electron beam with visible graticule lines on the tube's faceplate. An input signal is compared, at the time of intersection, with stored values representative of the graticule lines, and the deflection amplifier gain of the oscilloscope is adjusted until the graticule lines properly represent the measurement of the input signal.

Abstract: An alternating current sensing circuit for sensing the current supplied by a power supply of an electronic instrument includes an isolation transformer and at least one transistor connected across the secondary winding of the transformer. The isolation transformer provides galvanic isolation between the power supply and internal feedback circuitry that controls the power supply located within the instrument. The transistor clamps the secondary voltage on the transformer to a constant magnitude when the base-emitter junction is forward biased. In response to the sensed current, the secondary current of the transformer flows through the transistor when the base-emitter junction is forward biased to produce the constant secondary voltage. The secondary current provides a current sensing signal which is transmitted to the feedback circuitry.

Abstract: A switchable color filter (10) develops with the use of a single electro-optic switching device positioned between first and second polarizing filter means (14 and 16) an output of three desaturated colors that define an area (54) in color space. The switching device comprises a variable optical retarding means (12) that includes a variable optical retarder (18) and a quarter-wave plate (20). The first and second filter means pass light rays of three primary colors. The variable optical retarding means selectively provides zero, quarter-wave, and half-wave retardation of light rays passing through it to develop the three output colors. The quarter-wave plate is positioned such that it forms a circular analyzer for one of the three primary colors when the variable optical retarder provides quarter-wave retardation. Each of the three output colors is a mixture of at least two of the primary colors.

Abstract: Acquired sampled waveform data is displayed on a screen as a busform, wherein a change of state in the waveform during a sampling interval is represented by a solid block character on the screen, and wherein the lack of a change of state in any of the channels during a sampling interval is represented by a space character of the same width as the block character. The blocks and spaces representing contiguous sampling intervals are of the same width and are displayed in horizontal sequence across the screen such that the time between state changes is graphically represented by the horizontal distance between the blocks. Numbers indicating the associated waveform state are displayed when possible in the space or spaces following each block character.

Abstract: A method for compensating for video image distortion on a cathode ray tube (CRT) is accomplished by determining the distortion occurring along one axis of deflection of the CRT electron beam. The distortion is determined by predicting the position of the electron beam during a particular scan along the axis of deflection. The rate at which video image information is displayed (pixel rate) via the electron beam is varied according to the predicted position of the electron beam during the scan along the axis.

Abstract: A power supply switch circuit includes a transistor for switchably connecting portions of a current path between a standby power supply and a power supply controller, with a capacitor as a temporary current source for the controller once the path portions are disconnected. The transistor is coupled to a switch which causes the transistor to connect and disconnect the portions of the current path. The capacitor is coupled to the transistor for discharging current to the power supply controller for a predetermined time after the switch signals the transistor to disconnect the path portions. A power-down indicator senses this signal by the switch to the transistor and in response transmits an alert signal to the instrument logic warning that a break in current is imminent. This warning permits the logic to save relevant information while power is provided through the capacitor.

Abstract: A pressure sensing apparatus for use in an integrated circuit testing station is disclosed. The testing station includes a probe, a support structure, and lift means for moving an integrated circuit upward toward the probe. The invention specifically consists of a pressure pad secured to the support structure directly above the probe. The pad includes a resilient body portion having a rigid tip. Embedded within the pad is a piezoelectric element having electrical contact leads attached thereto. When the testing station is used, an integrated circuit is moved upward by the lift means toward the probe. As the circuit contacts the probe, it moves the probe upward. As the probe moves upward, it pushes on the pad, causing internal pressures to be generated therein. Such pressures are transmitted to the piezoelectric element which generates electrical impulses proportional to the pressures exerted on the pad.

Abstract: A method and control system for integrating machine independent software written in a high level language with the hardware and software characteristics of a selected processor system to generate an executable load module in the same high level language with selected machine codes merged therewith to be run on the selected processor system. The method and system includes the interactive preparation of a source file containing software, hardware and interrupt configuration specifications of the selected processor system in response to designer inputs. Also included is the processing of the source file to generate a linker command file and a configuration object file. Additionally, the machine independent software is linked with the configuration object file under control of the linker command file to generate the executable load module for the selected processor system.

Abstract: An electronic probe assembly provides previously recorded data as to probe identification and optimum compensation tuning of the probe to a connected "intelligent" test and measurement device so that proper test procedures may be confirmed, either by display of such data or by the generation of error messages.

Abstract: Apparatus for correcting astigmatism produced by the electromagnetic deflection yoke of a cathode-ray-tube includes plural stigmator electrodes provided with elongated slots through which the cathode-ray-tube's electron beam passes. Appropriate correction voltages, stored in digital memory, are applied to the stigmator and focus electrodes for bringing about re-focusing of the electron beam in appropriate axes for restoring a single point focus on the cathode-ray-rube's screen.

Abstract: In system and method for smooth line raster-scan display, a frame buffer containing a high resolution map of information of an image for display is read so as to furnish plural line stored information for each single line of the raster display. Display circuitry of the system receives the plural line stored information and varyingly weights same to furnish such single line Z-axis information (intensity control) for an X-Y display matrix, such as a CRT display terminal. Means are included in the system for display of the entire frame buffer content on a first fractional basis, e.g., a two thousand line resolution buffer to five hundred line raster. Selection circuitry of the system provides for reading out only a fraction of the frame buffer content, e.g., one-fourth or the five hundred lines thereof, on five hundred raster lines, thus providing true resolution zoom capability.

Abstract: An associative memory having a large storage capacity which also has the capability of being used as a conventional memory, i.e. accessed by physical location. A memory array (11) is accessed in conventional fashion by an address decoder (15). A mask/data drive circuit (13) controls the loading/reading of the memory array (11) when the device is in a conventional mode, and operates on the same pins to provide mask and search data when the drive is in the associative mode. In the associative mode, a plurality of match detect (17) circuits, one for each word location in memory (11), receive the output signals from the memory array (11). The match detect circuits (17) prioritize the output match signals from memory (11) and provide an output indicating the first or lowest word in memory (11) having a match. An address encoder (19) is responsive to the prioritized match output (if any) from the match detect circuits (17) to determine the physical location in memory (11) containing the matched word.

Abstract: A high-speed power amplifier for driving inductive loads is capable of operating at frequencies of at least 270 kHz. The drive amplifier includes an oscillator that develops a continuous square-wave signal having relatively short transition times and a regulated 50% duty cycle. The oscillator output signal is applied to a filar-wound impedance transformer whose response time characteristics do not change substantially the transition time characteristics of the oscillator output signal. The impedance transformer circuit includes a pair of transistors operating in a push-pull configuration simultaneously to maintain the relatively short transition times of the oscillator output signal and to develop the high-current transformer output signal needed to drive a power transistor switch. The power amplifier is designed to provide a base current signal that promotes better dissipation of the power generated in the power transistor as it operates at high switching speeds.