| 摘要 |
A hardware write protection for external mass storages of personal computers (PC) aims at preventing accidental modification of data and programmes by destructive software (for example computer viruses) or by an incorrect operation of the computer. For that purpose, the circuitry has an insert card (12) of a standard PC format that can be inserted onto the PC system bus and a medium high mass storage controller card (13). On the insert card (12) of a standard PC format are arranged an intelligent sector write protection system (1 - 11) and a standard PC system bus insert card strip (14). The medium high mass storage controller card (3) is inserted into the standard PC system bus insert card strip (14). All lines of the PC system bus on the insert card (12) of standard PC format are directly connected to the input of the intelligent sector write protection system (1 - 11) and all lines of the PC system bus, with the exception of the IOW line, are directly connected to the standard PC system insert card strip (14). The IOW line is connected to the standard PC system bus insert card strip (14) by means of the intelligent sector write protection system (1 - 11). |
