| 摘要 |
PURPOSE:To constitute the titled system so that the head address of a program which is written in a memory cannot be confirmed, and the contents of the program cannot be decoded, by only this computer system, by reading out the program by inputting a start address signal for showing the head address of the program from the outside of the computer system. CONSTITUTION:Prior to a start of an arithmetic operation, a signal for showing a specific address which is determined in advance is inputted to a decoding part 3 through an address 106 from a computer part 1 to which a start signal 105 is inputted, in accordance with the time when a power source is turned on and the time when a system is reset. As a result, from the decoding part 3, a detecting signal 108 is outputted. On the other hand, to the converting part, a start address signal 109 corresponding to the head address of a read-out start of a program which is written in a memory part 2 is inputted, a signal for showing the start address which the memory part 2 has is outputted synchronously with the detecting signal 108 and inputted to the computer part 1, the signal for showing the start address is applied to the memory part 2 through the address bus 106, the program is called and inputted to the computer part 1, and the arithmetic operation is started. |
