Patent ID: RE39822

Claim:
For use in a cathode ray tube display connected to a computer system, an apparatus for setting an ID code comprising: video amplifier means for amplifying image information input from said computer system to display on a screen of said cathode ray tube display; a key pad having an array of keys for generating a key input signal to compose an ID code; memory means for storing ID code data input via said key pad by a user's manipulation; a microcomputer for controlling said display responsive to a result of a comparison between said ID code input via said key pad with said ID code data stored in said memory, and for receiving horizontal and vertical frequency signals from said computer system to control an operation of said display; an on-screen circuit for converting a digital information signal synchronized with a train of clock pulses input from said microcomputer into an analog video signal having red, green and blue components; and mixer means for mixing said analog video signal input from said on-screen circuit and a signal input from said video amplifier means.