| 摘要 |
PURPOSE:To enable a host computer to perform input/output control with no consciousness of the difference of mode on an input/output device, by providing an initial mode register and a rewritable mode register. CONSTITUTION:An input/output controller 17 receives an input/output request from a host computer and controls the corresponding device 17. An initial mode register 25 stores the initial state of the control mode of the corresponding device 17, and a rewritable mode register 24 sets the working mode of the corresponding device 17. Then the contents of the register 25 is written to the register 24 when a power supply is turned on, and at the same time the contents of the register 24 is rewritten when a mode alternation request is given from the host computer. Thus the host computer can control an input/output control with no consciousness of the difference of mode of the input/output device. |
