| 摘要 |
PURPOSE: To record data to a floppy disc while keeping the data in a confidential state. CONSTITUTION: When data are recorded, an ID signal indicating ID data is magnetically recorded to a lower layer 12 of a floppy disc 1. A data signal indicating data to be recorded (data file) is magnetically recorded to the lower layer 12 of the floppy disc 1. A security signal is magnetically recorded to an upper layer 13 of the floppy disc 1 at least over the data signal recorded in the lower layer 13 of the floppy disc 1. When data are reproduced, the ID signal is reproduced from the floppy disc and the ID data represented by the reproduced ID signal are compared with input ID data. If two ID data agree, the security signal recorded on the upper layer 13 of the floppy disc 1 is erased. Thereafter, the data signal recorded to the lower layer 12 of the floppy disc 1 is reproduced. |
