 The Atari OS includes a subsystem for peripheral device input/output (I/O) known as CIO (Central Input/Output).Most programs can be written independently of what device they might use, as they all conform to a common interface; this was rare on home computers at the time.New device drivers could be written fairly easily that would automatically be available to Atari BASIC and any other program using the Atari OS, and existing drivers could be supplanted or augmented by new ones.