Abstract: A microprocessor is utilized to monitor and control the operation of an image projector and a magnetic tape cassette player. Inaudible cueing tones recorded on the tape allow the recorded narrative to be kept in synchronization with the image projected. A sync counter within the microprocessor keeps track of the amount and direction by which the image and tape are out of synchronism. The microprocessor controls a visual indication to the operator that shows the direction in which the tape must be moved to regain synchronization. When the tape is moved forward to achieve synchronization, the microprocessor will stop the tape after the cue pulse that precedes the narrative for the associated image. When the tape is moved in the reverse direction to achieve synchronization, the microprocessor will stop the tape just beyond the cue pulse at the beginning of the desired narrative.

Abstract: Method and apparatus for use with a magnetic tape playback machine to attenuate recorded audio signals relative to the super-imposed control signals while the magnetic tape is being transported past the sensing surface of a playback head. The control signals are recorded in a frequency range which is lower than the frequency range of the recorded audio signals. A spacer is attached to the sensing surface of the playback head to space the magnetic tape a preselected distance from the sensing surface and thereby attenuate the higher frequency audio signals relative the lower frequency control signals. The higher frequency attenuation obtained is independent of the frequency of the signals induced into the playback head and is thereby independent of the linear velocity of the magnetic tape as it is transported past the sensing surface of the playback head.