Abstract: In accordance with the duplication of bit-patterns on a recording medium of the present invention, presence of gaps as defined by one or more words of predetermined code in data is judged, then with having these gaps as the write-succession points, and placing an unwritable bit-pattern in these respective gaps, data is written in onto the recording medium of the transfer-destination. Thus, the write-succession points can be determined, and the occurrence of bit-shift can be avoided. In addition, transmission of data on the recording media over a long distance become possible.