Computer aided design system - using CRT graphical display and intersection card for rapid search of points of intersection

摘要

The electronic intersection card is used in conjunction with a CRT having a bistable memory, providing a graphical display for a computer-assisted design system. A character decoder, allowing loading and validation of the intersection card, is coupled to the read mode enabling circuit of the CRT, to delay circuit and to a logic circuit for transmission of the intersection coordinates. The delay circuit is connected to an interrogation signal generator coupled to an intersection detector, in turn coupled to the logic circuit. The delay circuit is also coupled via a clock generator to a vector generator and a multiplex circuit for selection of the X or Y axis interconnected with the logic circuit.