| 摘要 |
PURPOSE:To shorten a data saving time, by providing a data saving indicator, and saving blocks in which a data saved in a magnetic disk device is different from the data in a semiconductor memory by utilizing a vacant time when access from a host device is interrupted. CONSTITUTION:When the power source of a computer system is disconnected, a power source control circuit 44 sends a power source disconnection indicating signal to a data saving control circuit 42. The data saving control circuit 42 receiving the power source disconnection indicating signal refers to the data saving indicator of a saving indicator part 412, and when all of the data saving indicators are set at OFF states, it sends a power source disconnection permitting signal to the power source control circuit 44 immediately. When the data saving indicator set at an ON state remains, the block data of a data part 411 corresponding to the data saving indicator set at the ON state is saved in the magnetic disk device 43, and after that, the data saving indicator is set at the OFF state, and at a time when all of the data saving indicators are set at the OFF states, the power source disconnection permitting signal is sent to the power source control circuit 44. In such a way, it is possible to shorten the data saving time. |
