Abstract: An apparatus for controlling a drive mechanism of a panel display system includes a rotary member attached to a drive assembly, the rotary member having indicators located at known intervals that are detected to ensure that the drive assembly starts and stops at precise locations. In a preferred embodiment, the control system is applied to a panel display system that displays different scenes using an array of elongated three-sided display elements. The preferred control system includes an aluminum disk that is attached to rotate in connection with rotation of the drive assembly.