| 摘要 |
PURPOSE:To attain protection from copy which does not lose its validity even in case of copying between mediums including a gap area and an ID area, by providing a specific area, where a user cannot write data but can read data, on the medium. CONSTITUTION:There is, for example, a 16KB program, and the medium where this program is recorded is protected from copy. This program has a size corresponding to four sectors because of 16KBdivided by 4KB=4. This program is recorded in areas from sector number 1 to sector number 4 on the track of track number 30. Two bytes in each of areas 504, 506, and 508 of sector number 2, sector number 3, and sector number 4 are used for a copy protect code, and 6 bytes in total area used for the copy protect code. The number of kinds of value which the copy protect code can take is 2<48>=2.8X10<14>, and a complete copy including the copy protect code is obtained only once when copying between mediums is performed 2.8X10<14> times. |
