Disk drive incompatible firmware recovery

摘要

In a disk type data storage device wherein the firmware used to control the device is partitioned with a first portion stored in the control circuitry and a second portion stored in the reserved area of the disk surface, the replacement of one of the portions in the field may cause the drive to have different levels or releases of firmware that will not function together. This disables the drive until diagnosed and corrected. The structure disclosed includes identifiers associated with the firmware portions and the provision of a copy of the firmware first portion as well as the firmware second portion on the disk. The firmware first portion on the disk is normally never accessed and is a version compatible with the firmware second portion on the disk. During the power up sequence, the identifiers are checked for compatibility and the sequence normally continues. In the event that a portion of the firmware has been replaced and a finding of incompatibility occurs, the ROM, first portion of firmware (stored in electrically erasable, electrically programmable read only memory) in the control circuitry is erased and replaced by the firmware first portion stored on the disk. The firmware portions are thereupon compatible and drive operation continues without user intervention or awareness of the problem except for a one time, modest lengthening of the power on sequence. <IMAGE>