Abstract: A D-MOS storage FET is disclosed having a floating and a controllable gate. A storage matrix with such D-MOS FETs is also disclosed. Data words can be read out and can be programmed from several bits. Ultraviolet light is used for erasing. The storage FETs can be used for storages in data processing equipment including telephone exchange equipment.

Abstract: The present invention relates to a modular logic circuit, which is preferably utilized in a telephone switching system, comprising electronic logic elements using binary logic operation. The input terminals of the circuit have one input signal at a time applied to them whereupon an output signal is supplied through its output terminals; the output is dependent on how the modular circuit was previously set by electrical means. The logic elements comprise transistors in a matrix arrangement connected to horizontal and vertical lines. The modular circuit of the present invention is characterized in that it can be set any number of times by means of a first setting signal applied to the input terminals and a second setting signal applied simultaneously to the output terminals.

Abstract: A n-channel storge field effect election device having a floating gate completely surrounded by insulating material is described. During writing in the storage the floating gate is charged negatively by hot elections generated in its own channel by channel injection. After charging, and particularly during reading, the gate inhibits drain to source current, by means of its negative charge.