The Gemini General Purpose Controller is such a flexible control unit that most people have trouble keeping track of all the functions that it can perform. Therefore we present, in diagram form, a sample application of this device. The Gemini receives commands from the Hercules or the Cygnus by means of a communication network, and operates a wide variety of devices by means of the appropriate device interfaces. Each Gemini has four device control ports, each of which can be set to control any type of device illustrated below. In addition, each Gemini has one independent 8-channel switch port.