| 摘要 |
PURPOSE:To prevent assuredly a fact that the software is copied to an undesired recording medium by setting a PVID with which recording or change is made impossible with a normal writing means and is detected as a defect and storing the software to a recording medium in a form which is effective for the first time when the information related to the PVID position is used as a key. CONSTITUTION:The software is recorded to a floppy disk 1 in a format of sectors of fixed length (256 bytes). A small hole 3 of about 1mm. diameter is formed to a sector (PVID sector) of a track number T and a sector number S. This hole 3 is equal to a PVID with which no change is possible with a magnetic writing means. The software is stored to the disk 1 in a form which is effective for the first time when the information on the PVID position in used as a key. In other words, the disk 1 contains both the hole 3 serving as a PVID and the software P where an FVID check routine C is buried. |
