Man-machine console facilities for computer-aided design

The backbone of the man-machine communication link in Computer-Aided Design is a console whose principal components are the display scope and the light pen. The display scope is an ordinary cathode ray tube which is controlled by the computer by means of program instructions. It allows the computer to output to the man rapidly in easily interpreted graphical form. The data displayed can be textual, pictorial, or a combination of the two. The light pen is a photosensitive device which responds to the light generated by an intensified point on the scope face and which amplifies, shapes and transmits this response back to the computer where it can be tested by the program and used as a branch condition. The display scope and light pen form, so to speak, the paper and pencil of the designer, but they possess some extremely useful additional properties which open a whole new expressive medium. The following papers describe some of the fascinating and invaluable facilities which are provided by this basically simple hardware. In this paper we present some basic information about the hardware itself and describe some of the sophistications appropriate to the Computer-Aided Design problem.