ROM-RAM medium and storage device thereof

摘要

A ROM-RAM recording medium includes a ROM portion in which main information is recorded by a physical change on an optically transparent substrate and a RAM portion formed on the ROM portion as a recording layer that allows writing of main information at least once. The ROM portion is provided with a sub-code area for recording sub-information. A sub-code area for recording sub-information is provided in the RAM portion arranged at physically substantially the same position as the sub-code area of the ROM portion in a track direction.