Abstract: The input/output system for a computer of this invention permits a peripheral device and its associated peripheral processor to be connected either (a) directly to the central processor unit of the computer, or (b) to a remote hardware peripheral control device which permits the central processor unit to directly control the peripheral processor, or (c) to a remote input/output controller which controls the peripheral processor independently of the central processor unit of the computer. The input/output system of this invention permits the use of the same software set stored in memory to control the input/output operations of a selected peripheral device regardless of where the peripheral device is connected.