Computer memory with anti-virus and anti-overwrite protection apparatus

Abstract

The invention is embodied in a computer including a memory and a memory protector responsive to a list of key memory locations containing information to be protected, the memory protector including (a) a write protection circuit—operating independently of the computer—which prevents any write requests specifying the memory locations contained in the list from being carried out, and (b) a manual protect enable switch for enabling and temporarily disabling the write protection circuit, thus allowing special or temporary access to the protected memory locations. The write protection circuit may be implemented as a programmed microprocessor with its program stored in a non-volatile read-only memory, or as a dedicated hard-wired logic circuit, such as a field programmable gate array. The list of key memory locations may be stored in a non-volatile memory accessed by the write protection circuit. More conveniently, the list is contained in a protected memory location (i.e., a memory location specified on the list itself), the list being downloaded to the write protection circuit.