| 摘要 |
PURPOSE:To prevent the erasion of data even with exchange of a board containing a semiconductor memory by selecting a subconnector via a switch circuit and transferring the data stored in the semiconductor memory to a storage means via the subconnector and to hold them there. CONSTITUTION:At maintenance a switch circuit 3 is set in a maintenance state by a maintenance engineer. Then the circuit 3 selects a subconnector 6 and is connected to a data storage circuit 8. The data read out of a semiconductor memory 1 via a read/write circuit 2 are stored in the circuit 8 via the subconnector 6. Then a semiconductor memory board 7 is removed from a semiconductor storage and a defective element is replaced with the nondefective one. When the board 7 is loaded into the storage again, the data stored in the circuit 8 are written into the memory 1 via the subconnector 6. Thus the erasion of data is prevented at maintenance. |
