| 摘要 |
PURPOSE:To alternately and continuously access ROM information and RAM information at high speed by concentrically arranging ROM areas and a RAM area so that they are adjacent to within a prescribed distance wherein an optical head can be positioned at high speed. CONSTITUTION:The ROM area (first area in which only reproduction is erecuted) 3 is provided in an inner peripheral part and the RAM area (second area in which recording and reproduction are executed) is provided in an outer peripheral part. The ROM area 3 is angle-divided in the RAM area 2 to coexist in the outer-side. Concentric tracks are provided in the RAM area 2 and the ROM areas 3, and data is recorded/reproduced and reproduced along the tracks. Consequently, information stored in the ROM area 3 and that stored in the RAM area 2 can continuously be read and written while the optical head 1 traces one track. Thus, ROM information and RAM information can alternately and continuously be accessed. |
