| 摘要 |
PURPOSE:To protect data in a main storage and to reduce the frequency of writing into a disk at the time of updating a record by arranging a storage device which is equivalent to the main storage and which has a power device different from that of a system in parallel to the main storage. CONSTITUTION:A memory back-up device 3 has a control line in common with the main storage 2, and doubly stores the content of the main storage 2 by making the content of the memory equal. Thus, the memory back-up device 3 does not lose data since it uses the back up power device 6 different from the main power device 5 when the system is down due to the occurrence of a fault in the main power. Consequently, the system can be restored to the same state when it is down by copying data in the device 3 in the main storage 2. When power normally operates, storage precision improves by doubling a storage processing and checking both contents, and a processing speed can be improved by reducing the number of access times for a secondary storage 4 at the time of a transaction processing. |
