Patent ID: 7076649

Claim:
A disk drive for reading information from a disk and outputting the read information which is to be provided to a host, comprising: an accessing circuit which accesses the disk and generates the read information from the disk; an interface circuit which transfers the generated read information from the accessing circuit to the host; and a microcomputer, coupled with the accessing circuit and with the interface circuit, being located on a semiconductor substrate and including a central processing unit and an electrically erasable and programmable nonvolatile memory, wherein the electrically erasable and programmable nonvolatile memory stores a first program, a second program and a third program, wherein using the stored first program, the microcomputer controls the accessing circuit so that the operation of the accessing circuit is controlled by the stored first program, wherein using the stored second program, the microcomputer is adapted to check data in the electrically erasable and programmable nonvolatile memory, and wherein using the stored third program, in response to the result of the check by using the stored second program, the microcomputer is adapted to transfer data for rewriting the contents of the first program in the electrically erasable and programmable nonvolatile memory from the host to the electrically erasable and programmable nonvolatile memory via the interface circuit.