Abstract: Keyboard-controlled apparatus for producing video signals for standard television receivers includes a random access memory having a multiplicity of storage positions each of which corresponds to a preselected discrete portion of the TV raster. Data stored in the random access memory is sequentially read from memory in synchronism with the scanning of the television receiver so that a desired video signal is generated at each discrete position of the cathode ray beam. Data is read into the random access memory at preselected storage positions depending upon a particular image to be displayed. The data writing process is under the control of a micro-processor which is programmed to cause the stored image data to be varied in accordance with the condition of the user-controlled keyboard.