Abstract: A microprocessor-controlled scanning system having a scanning element which is driven by a three-phase DC motor has low quiescent current motor driver circuitry. A bus driver chip normally used to drive a computer memory bus is novelly used in place of a prior art triple half-bridge circuit to source and sink the drive windings of the motor, thus significantly reducing the drive circuitry power requirement.

Abstract: A video display controller for controlling the display of characters stored in a bit plane memory. The characters to be displayed are arranged in the bit plane memory in a set number of scan lines with a set number of data bits in each scan line. Attribute bits are included in one scan line of data bits in each character to be displayed. The controller includes a data bus for receiving data from the bit memory plane in bytes, each of which includes data bits of one scan line. Each data byte from the data bus is clocked into a shift register, with the data byte shifted out of the shift register sequentially, one bit at a time. Attribute bytes are selected from the data bus and an attribute logic circuit applies the attribute bits to the sequential data bits of a corresponding character to be displayed.

Abstract: The present circuit incorporates a latch which latches an asynchronous input signal and provides a latched output signal to the first stage of a two stage synchronizer. An AND gate receives the latched output signal and the output from the first stage such that the output signal from the AND gate follows the output of the first synchronizer and is presented as an input to a second stage of the two stage synchronizer. The second stage is clocked, as is the first stage, with the system clock signal to provide the synchronized output signal. An asynchronous reset of the latch causes the output of the AND gate to go low which in turn causes the output of the second stage to go low asynchronously.

Abstract: A scanning system having a motor-driven scanning element automatically shuts down a scanning laser when the motor is either inoperative or operating below a safe speed. A microprocessor already used to drive the scanning circuitry is also used to control the operation of the motor, including commutation logic, and also controls the automatic laser shut-down. This results in a significant reduction of power requirement.

Abstract: An interlocking base for use with stacked interlocking electronic assemblies which increases the mechanical stability of the base-stack combination. The increased stability allows a stack of up to four electronics assemblies to be subjected to an inclination of 15 degrees from the vertical in any direction without falling over. The base is furnished with an AC power cord and an ON/OFF AC power switch to provide single switch control of the ACs power conducted to the electronic assemblies of the stack. Single switch control saves operator time and motion, and also prevents accidentally leaving one of the assemblies of the stack ON while turning all the others OFF at the completion of work.

Abstract: The subject invention is a power supply comprising a magnetic amplifier, filter, back-up battery, switch-over regulating circuit and error amplifier. The magnetic amplifier receives a plurality of AC pulses and controls the pulse width of the pulses. The filter converts the pulses to a DC output. The switch-over regulating circuit connects the battery to the DC output. The error amplifier monitors the DC output and provides, at its output, an error signal to the magnetic amplifier and the switch-over regulating circuit.

Abstract: A high speed computer data transfer system includes a clamping circuit for limiting pre-charge voltages in the case where multiple pre-charge cycles occur before a pull-down operation. Data bus voltage swings between logic high and logic low levels as well as pull-down times are reduced, thus lowering the time needed to transfer the data. The preferred embodiment is implemented using complementary metal-oxide-semiconductor (CMOS) technology.

Abstract: An integrated circuit structure and fabrication process for creating field oxide regions having substantially no bird's beak, a relatively planar concluding surface, substantially no stress induced dislocations at the edges of the active regions, and a substantial absence of notches or grooves at the edges of the active silicon, by a selective combination of material dimensions and process operations. In one form of practicing the invention, the process utilizes a relatively thick pad oxide below the masking nitride layer, and a second, very thin, sidewall masking nitride layer. The thin sidewall masking nitride layer does not utilize an underlying pad oxide layer, but may include a thin underlying screening oxide.

Abstract: A test circuit for the output buffer of an integrated circuit permits testing for faults in the electrical connection of the output buffer to external conductors on a printed circuit board and for faults in the output buffer itself. A tester device supplies two test control signals to the test circuit for causing the output of the output buffer to be forced high, to be forced low, to pass the logic level of the internal data signal provided to the input of the output buffer, or to go into a tri-state (high impedance) condition.

Abstract: An apparatus for containment and alignment of wire terminations has a wire holder with a slidable retainer. The front of the wire holder has oval-shaped holes for partially receiving several oval-shaped wire terminations to be connected to electronic equipment, and for reducing rotational motion of the wire terminations. Smaller holes connected to the oval-shaped holes receive the wires, but prohibit further movement of the wire terminations into the wire holder so that wire terminations uniformly protrude from the wire holder. Slots at the back of the wire holder receive the wires, which wires are frictionally locked into place by the retainer.

Abstract: A printer ribbon cassette mounting apparatus includes a pair of aligning posts and a pair of resilient latch members mounted on the lower surface of the cassette housing. The posts and latch members engage complementary openings in wall portions of the printer with which the cassette engages. Two restrainers extend from the lower surface of the cassette in parallel spaced relation to the latch members, and prevent excessive bending of said latch members.

Abstract: A method and apparatus for lowering integrated circuit chip ambient temperatures uses negative pressure to induce cooling liquid flow, rather than prior art positive pressure approaches, thereby preventing undesirable cooling liquid leakage outside of the cooling region. The cooling liquid is deaerated to eliminate performance degrading air bubbles, which are a by-product of the negative pressure approach.

Abstract: An emitter coupled logic (ECL)-to-complementary metal-oxide-semiconductor (CMOS) logic level translator is temperature compensated to track temperature induced shifts in the ECL logic levels. The translator includes a differential amplifier with mid-range reference voltage. A reference voltage generator supplies the reference voltage to the differential amplifier and has a temperature sensitive transistor which changes the value of the circuit output (reference) voltage ambient with temperature shifts.

Abstract: A circuit for generating clock and control signals from first and second asynchronous binary signals. The circuit generates first and second pulse signals responsive to the first and second asynchronous binary signals, a clock pulse signal responsive to the first or second pulse signal, and an identification control signal to indicate which of the two binary signals is responsible for the clock signal. The circuit is also responsive to the first and second pulse signals for generating an overlap control signal to indicate overlap in the first and second pulse signals.

Abstract: A method for detecting low battery voltage in a hand-held scanner capable of reading the likes of a bar code measures the speed of the motor driving the scanning element and compares it to stored values. The stored values represent motor speeds directly corresponding to maximum and minimum battery voltages. The stored values can be introduced to the scanner for example, at the factory. If the motor speed is found to be lower than the speed corresponding to the minimum acceptable battery voltage, user understandable message is produced, which necessitates either battery re-charging or replacement.

Abstract: An arrangement to provide a card cage of an electronic system with a retaining bar. The retaining bar simply and quickly latches in to holes drilled in the side of the card cage. Similarly, the retaining bar quickly unlatches from its holes to provide access for maintenance personnel. The retaining bar has a spring loaded latch element at each end of its length. It has a bar member with a U-shaped cross section in order to prevent excessive bending in the middle. The retaining bar further has a layer of resilient material between the U-shaped bar member and the printed wiring cards to provide a force against each card to retain it in its respective card position. The resilient material may be highly insulating or it may be anti-static as the technology requires.

Abstract: A new, multi-user data communication system is presented which is inexpensive and does not require any hardware changes to the central processor/system host. The standard serial data input/output port of each terminal is adapted from the standard single-user configuration to a party line, multi-user configuration by the addition of a simple and inexpensive interface circuit within each terminal. After the interface circuits are installed, the terminals can be interconnected to each other and to the central processor/system host using standard serial cabling. The party line interface circuit allows each terminal to access the non-busy serial data bus on a first-come-first-served basis. An interference detector and interference handling circuit are provided also to prevent data errors in the event of a possible data collision.

Abstract: A cable of wire (information bus, power supply, etc.) carrying method and apparatus for modular computer cabinets and the like in which the cabinet frame end walls have notch-like voids. The notches, preferably on the rear side of the cabinets are nearly fully enclosed, save a small opening (to preserve structural integrity) through which the cables may enter. The openings are covered by closure members and decorative trims once the cable is in place. The result is modular computer system without unsightly wires, and in which the modules may be easily and quickly inserted or removed without the need for dismantling the cable attached to the backs of the other modules.