| 摘要 |
PURPOSE:To transfer the data to other system input/output device without passing through the main storage device of a central control unit by switching and connecting selectively user's own system and other system input/output devices by the control from a host device. CONSTITUTION:A host controller 1 can control the input/output of the data of an input/output device 4 to belong to its own system through an own system input/output controller 3 respectively and constitutes the duplexed system. A selecting part 18 switches its own system and other system input/output devices 4 and connectes them based on the control of the input/output controller 3. The input/output controller 3, when an instruction is received from the host controller 1, controls the selecting part 18, and transfers autonomously the data of its own system input/output device 4 through the input/output controller 3 to other system input/output device 4. Consequently, the load at the central control unit is decreased, and the data transfer time can be shortened. |
