The input-output system of the Lincoln TX-2 computer contains a variety of input-output devices suitable for general research and control applications. The system is designed in such a way that several input-output devices may be operated simultaneously. Since the computer is experimental in nature, and changes in the complement of input-output devices are anticipated, the modular scheme used will facilitate expansion and modification. The experimental nature of the computer also requires that the input-output system provide a maximum of flexibility in operating and programming for its input-output devices.