A magnetic disk sub-system provides for sudden cutting off of a main power supply such as a power failure so that the backup by battery is effected to supply electric power to the cache memory from a battery upon cutting off of the main power supply in order to protect data in the cache memory and when...http://www.google.com.au/patents/US5905994?utm_source=gb-gplus-sharePatent US5905994 - Magnetic disk controller for backing up cache memory
