| 摘要 |
PURPOSE:To prevent a program from being copied illegally, by providing a storage circuit to which only one time of write can be performed, and writing a proper value in the storage circuit in respective device at the delivery time of the device. CONSTITUTION:The titled system constituted of the address decoder 21 of the storage circuit, a memory write control circuit 22, and an ordinary readable/ writable memory 23, and furthermore, a storage circuit (EPROM)24 to which only one time of write can be performed is provided. At the delivery time of the device from a factory, the program (inspection program), after confirming that the operation of a personal computer is correct, writes the inherent value at a special address prepared for the EPROM24 at every device. Meanwhile, when the device is used for the first time by the program, such as the program of a word processor marketed in a general market, the inherent value of the device is read out from the EPROM24, and the program is changed so as not to be operated by the program other than the value. In this way, even when the stored content of a medium on which the program is stored, is copied, it is impossible to use the medium in another device. |
