Abstract: A control system synchronizes the operation of a plurality of controlled mechanisms such as slide projectors by means of unique frequency tone-binary code signals recorded on a magnetic tape. In a particular embodiment, six slide projectors and one movie projector are controlled in any desired combination or sequence and with two different fade-in, fade-out speeds and in synchronism with an audio program on another track of the tape.In this specific embodiment, four different frequency tones are used in conjunction with binary codes to provide unique slide advance and lamp control of the projectors.An encoder enables the user to make up his own programmed tapes.