| 摘要 |
PURPOSE:To prevent copying of an external memory unit by discriminating whether first character data for copy prevention of an information processor and second character data of the external memory unit have prescribed relations or not. CONSTITUTION:When an external memory unit 16 is set to an information processor 22, a memory switching means 32 forcibly switches the address space, which the information processor 22 can access, to a first memory space. Before the comparing operation, second character data stored in the external memory unit 16 is displayed on a display means 14. Thereafter, a validity discriminating program stored in an internal memory 30 is executed to compare first and second character data; and when these data have prescribed relations, the memory which the information processor 22 can access is switched to the external memory unit 16 by the memory switching means 32 and the access to this second memory space is permitted. Thus, copying is completely prevented. |
