Abstract: The present invention employs random electrostatic discharges to stress test electrical machinery, particularly digital computer systems running repetitive diagnostic programs. There is provided an interactive capability which allows the user to determine test duration either in terms of a fixed time or in terms of a specified confidence level, the latter case being one in which the system provides the user with an indication of the run time required. Significant improvements over deterministic "zapping" devices result.

Abstract: An interplanetary conflict game comprises a game board having first indicia thereon which are symbolic of the solar system and include planets, stars, and travel routes between the stars. The gameboard also includes a second indicia to determine the distance between the stars. A plurality of rocket markers for each player are manually moved by a player between the stars and planets and are used to fire at an opponent player's rocket or to capture an opponent's planet. A group of rating spheres used in conjunction with each rocket marker indicate the numerical rating of the rocket markers. A firing chart determines a firing range between a players rocket and an opponent's rocket. A promotion chart is used for determining the proper rating sphere for the rocket markers. A legend chart indicates the number of moves for a rocket marker as indicated by its rating sphere.

Abstract: A strip-line directional coupler is provided in which the volumetric size is reduced without a reduction in electrical characteristics. The input and output coupling lines are wound into separate spirals each having the same pitch so that they can be located at a fixed distance with respect to one another which is sufficiently close along their entire length to provide coupling of an input signal from the input coupling line to the output coupling line in the backwards direction. A first and second ground plane is located one on either side of and a small distance from each spirally wound input and output coupling line. A dielectric material is located between the input and output lines and between the ground planes and the input and output lines.

Abstract: A directional coupler arrangement is provided in which a plurality of directional couplers are cascaded by connecting the thru terminal of each coupler to the input terminal of the succeeding coupler and connecting the output terminal of each coupler except the last to the forward terminal of the succeeding coupler so that the desired backward coupled signal of each of the couplers arrive simultaneously at the output terminal of the last coupler so as to be additive and thereby produce an enhanced backward coupled signal. The forward coupled signals arrive at the forward terminal of the first coupler either out of coincidence or in a subtractive mode thereby minimizing the forward coupled signal.

Abstract: A data communication system is provided in which the data handling capacity of the system is doubled. The data in the system travels on a single wire in both directions simultaneously. Each pair of terminals associated with the communication system is interfaced with the single wire by a repeater. The repeater includes first and second directional couplers for coupling data signals from the repeater to the wire in the one direction and in the opposite direction, respectively, without substantial signal interference with signals being received by the repeater on the same wire. A wrap control function is included in the repeater which allows data signals to be placed on the wire going in the opposite direction from the received signals.