| 摘要 |
PURPOSE:To prevent the waste of data by sending data to another file device from a file device which is shared by plural file controllers when the data transfer preparation end signal sent to the file controller is rejected. CONSTITUTION:File controllers 101 and 110 share file devices 201-20n. When the controller 101 requests a data access to the device 201 via a line 222, a transfer control circuit 211 sends a data request signal to a data source 212 via a line 231. The source 212 transmits the data transfer preparation end signal to the controller 101 via the circuit 211 just before the desired data emerges at a reading head. Receiving this end signal, the controller 101 sends a reception permitting signal to the device 201. However a reception rejecting signal is transmitted if the controller 101 already transferred data to a device other than the device 201. As a result, the device 201 sends the transfer preparation end signal to the controller 110 to process the desired data with no waste. |
