| 摘要 |
PROBLEM TO BE SOLVED: To completely eliminate illegal communication by transmitting a self-annihilation code from a master station to a communication terminal and disabling communication between the communication terminal and the master station from this instance when there is a non-coincident signal in a non- coincidence storage memory. SOLUTION: When a correspondence flag for a production number, password number and identification number (ID) is F=1, a CPU 23 reads a self- annihilation code 28 out of a communication program ROM 26 to invalidate an illegal KARAOKE control part 1 without offering services in spite of the storage of identification number (ID) corresponding to the production number and the password number. This self-annihilation code 28 is sent through a communication line 12 to the KARAOKE control part 1 and communication is terminated. When the flag is already turned to F=1, it shows the existence of original KARAOKE control part 1 with which the illegal KARAOKE control part 1 was previously detected and duplicated equipment was illegally prepared or the duplicated illegal KARAOKE control part 1. Thus, the original KARAOKE control part 1 is also disabled for use together with the illegal duplicated equipment. |
