| 摘要 |
PURPOSE:To complete a data protection function, by providing a mode selecting circuit with a secret number to a magnetic disc device mounting fixed discs. CONSTITUTION:A mode selection circuit 1 consists of a secret number set circuit 2 and the 1st detector 3, and the circuit 2 inputs a secret number consisting of 4-digit figure, for example, from a keyboard to set the state of a magnetic disc, and the detector 3 interpretes this secret number and limits the data write/ read in accordance with the preset number. The 1st detector 3 limits the setting circuit of the secret number, and when the number of times of setting exceeds, e.g. there, this is detected and a lamp or a buzzer is activated via an alarm circuit 12. Thus, the data security and secrecy protection can be completed. |
