| 摘要 |
PURPOSE:To make normal read write operations possible even if an index mark signal cannot be detected, by detecting the end of a sector, which is placed before a part where the index mark signal should be detected, and the start of another sector which is placed after said part and writing the index mark signal again between these detected end and start. CONSTITUTION:A control circuit 2 performs the same operation as the read operation of a sector #4 (24) to detect the end position of the sector #4 (24), and a counter 21 starts counting pulses generated from a clock 22. The control circuit 2 monitors the output of a sector detecting circuit 27 to detect the start point of a sector #1 (21) and writes a special SYNC signal just before data. The value of a time T is obtained in accordance with the counted value of the counter 21 at this time. The write timing of the index mark is determined in accordance with the value of the time T, and the index mark signal is written again at the timing. |
