Abstract: An EPROM cell comprises an MOS device including a floating gate electrode overlying, and ohmically insulated from, the channel region of the MOS device, and a separate diode including a p-n junction having a substrate surface intercept. A floating gate electrode overlies the diode p-n junction intercept and is ohmically isolated therefrom by an intervening insulating layer. Writing of data into the floating gate electrode of the MOS device is achieved by causing a voltage breakdown across the diode p-n junction and the flow of high energy electrons across the junction. A voltage is simultaneously applied to the diode gate electrode thereby attracting some of the high energy electrons through the overlying insulating layer into the diode floating gate electrode. The diode gate electrode is ohmically connected to the MOS floating gate electrode on which some of the electrons are stored for affecting the turn-on, turn-off characteristics of the MOS device.

Abstract: An autocollimator having particular utility in optical aiming systems for the cannons of battle tanks comprises a pair of light sources for directing two beams of light along different paths towards a light reflector mounted, for example, on the muzzle of a tank barrel. The two beams of light are thus reflected along different paths towards a position sensitive light detector suitable for providing an output electrical signal indicative of both the receipt thereon of one or both of the reflected light beams and the position of the light beams on the light detector. The light sources are alternately turned on and off in non-overlapping time periods to provide identification of which of the two beams is being detected by the light detector.