| 摘要 |
<p>PURPOSE:To make the data protecting function complete by effecting the selection between the whole track accessible mode and the mode, in which no track other than a special one is accessible. CONSTITUTION:The magnetic disc is composed of: a key switch 1; a detector 2 for judging the addresses of the 0 track, which is taken by a positioner under the initial condition of the disc device, and an inspection track for maintenance; a resistor 3 for setting a cylinder address; a one shot 4 which is controlled by the switch 1; and a leak control circuit 5 for effecting leak control in accordance with the cylinder address. If the switch 1 is set under a conductive condition when in the operation other than a normal operation, the positioner is positioned in the 0 track. Thereafter, access is not possible other than the 0 track and the inspecting track for maintenance. If the key is removed after the switch is set, the data on the disc are protected.</p> |
