The first video game was made in 1958 by William Higinbotham. It was Tennis for Two and played on a on an oscilloscope, which has a cathode-ray tube similar to a black and white TV tube. In order to generate the court and net lines and the ball, it was necessary to time-share these functions. While the rest of the system used vacuum tubes and relays, the time-sharing circuit and the fast switches used transistors, which by 1958 were coming into use.