| 摘要 |
PURPOSE:To avoid useless time for the operation of an input and output device, by constituting the device so that two input and output devices can exchange data mutually without intermediation of programs of a CPU. CONSTITUTION:A CPU1 executes an input start instruction to an input and output controller 3a and executes a conditional output start instruction to an input and output controller 3b. Every time when the device 3a fetches data through an input and output device 4, the device 3a transfers data to a main storage device 2. On the other hand, the device 3b fetches a main storage address every time when it is given on an input and output control channel. When this fetched main storage address is included within the main storage address designated, the device 3b fetches data on the input and output control channel succeeding to the main storage address and stored it in an auxiliary storage device 5. The devices 3a and 3b report the end of interruption to the CPU1 when the data transfer of the designated amount is finished. Thus, the exchange of data can be made without intermediation of the program of the CPU1. |
