| 摘要 |
PURPOSE:To prevent the destruction of files due to operation mistake, by mechanically locking a disc to a device during the execution of program. CONSTITUTION:A door locking mechanism 9 and a counter circuit 1 are provided, and the circuit 1 is counted up, if the data on a floppy disc such as in case when the file is opened or at the time of writing to a table on a floppy disc is not in coincidence with the data stored in a buffer, and it is counted down, if they are in coincidence such as in case when the file is closed or at the time of ineffective processing of table. If the content of the counter 1 is zero, the door which is opened or closed by attaching and detaching the disc of a floppy disc driving device 10 is unlocked and if the content of the counter 1 is other than zero, the door is locked. |
