An unit which provides the necessary interfacing between a peripheral device and the computer input/output system. It provides the decoding of the computer commands relating specifically to a particular device, it also develops the necessary control voltage levels and the timing for the operation of the peripheral device.; 一种为外围设备和计算机输入输出系统间提供所需接口的装置,对特定设备有关的专用计算机 命令进行译码,产生必须的控制电压电平及同步［定时］信号去控制外部设备。同input/output controller。