| 摘要 |
PURPOSE:To improve the use efficiency of sectors, by writing information continuously on a prescribed number of sectors and reading this information to check defects and using sectors whose number is equal to the number of defective sectors following said sectors as alternative sectors. CONSTITUTION:A series of sectors, for example, light sectors 1-8 are accessed continously to write information. Information is read out to check defects. If sectors 2, 3, and 6 are defective, three sectors following the sector 8 are used as alternative sectors 2', 3', and 6', and information is written on these sectors, and these sectors are checked; and when defective sectors do not exist, the write of information onto next light sectors is started. Each sector consists of an ID part 10 to specify the sector, a flag 14 to indicate the defect, a flag 13 to indicate the alternative, a control field 14 including a start point45 15 of alternative sectors, and data 11. Number 9 is written in the pointer of each sector when information is written onto fist light sectors, and 1 is added to the pointer each time a defective sector is detected, and thus, alternative sectors are assigned. Thus, a sectors are used effectively. |
