| 摘要 |
PURPOSE:To prevent destruction of data of fixed information on cylinders except the maintenance cylinder, by petmitting the write to the maintenance cylinder even under the write inhibition state only when the address of the maintenance cylinder is detected. CONSTITUTION:The magnetic disc consists of cylinders for maintenance and cylinders for fixed information. Read only/write enable switch 4 is set to the read only state (write inhibition), and the address of a maintenance cylinder is detdcted by gate 2, and output 2a is generated. At this time, the output of flip flop 7 becomes the write enable state, and the device becomes writable. Next, when a cylinder (where fixed information is recorded) except maintenance cylinders where fixed information is recorded is prevented. |
