| 摘要 |
<p>PURPOSE:To avoid head clash, by removing dust through the seeking of the cylinder at the center and external circumference side of disc from the head stop position at least once or more, if no seeking operation is present within a given time, at the magnetic disc. CONSTITUTION:When the memory address of the cylinder address register 3 of the clash control section 2 and the write-in/readout address ADR are detected for the coincidence at the detection circuit 4, the counter 5 is cleared. When the disc pack control unit DPC is in use, the counter 5 receives the clock pulse CLK, counts the time when the disc stops on the same cylinder and timeoverflow signal l5 is produced for a given time or more elapsed. With this signal, the control circuit 6 feeds the request signal RS and the address signal SA which seek the cylinders at the center and at the outermost side at least once with the busy signal BSY and the end signal CMP from the control section 1, to the control section 1, allowing to remove dust and to prevent the head clash.</p> |
