| 摘要 |
<p>An optical disk (1) has sector ID areas (2), a disk ID area (3), a table of content area (4), a ROM area (5) and a RAM area (6). The ROM area stores software programs and basic data and is made non-rewritable by employing a physically permanent recording means, such as embossing ditch patterns, whilst the RAM area is left rewritable. In addition, the ROM has an erasing program, which automatically executes an erasing operation on the recording region. Because of the physical impossibility of an erasing operation this does not affect the ROM portion of the optical disk. If the contents of the ROM is illegally copied onto a rewritable disk, however, then the erasing program comes into effect and prevents the copy disk from being used.</p> |
