Patent ID: 7024571

Claim:
A conversion card to convert a conventional general-purpose personal computer into a mass storage appliance dedicated to performing mass data storage functions defined by a mass storage operating system (MSOS), the personal computer having a primary expansion bus by which to connect peripheral devices and over which to communicate signals with the peripheral devices connected to the primary expansion bus, the peripheral devices including at least one disk drive mass storage device with respect to which to read and write data, the personal computer also having a basic input output system (BIOS) which loads programs in response to boot probe signals, the loaded programs operating the personal computer and the devices connected on the primary bus as the mass storage appliance, the conversion card comprising: a bus interface on the conversion card to connect the conversion card to the primary bus and through which to communicate signals with the conversion card; a secondary bus on the conversion card, the secondary bus extending the functionality of the primary bus onto the conversion card; a bridge on the conversion card connected between the interface connector and the secondary bus to exchange signals between the primary bus and the secondary bus; a solid-state, memory card on the conversion card and containing nonvolatile code which defines the MSOS and which emulates a disk drive for purposes of booting the MSOS code in response to boot probe signals communicated from the BIOS on the primary bus; a disk controller on the conversion card and connected to the bridge and the memory card, the disk controller responding to boot probe signals communicated by the bridge on the secondary bus to identify the memory card as a disk drive and to transfer the MSOS code from the memory card on the secondary bus to the bridge for communication through the bus interface to the primary bus; the personal computer responding to the MSOS code to establish mass storage functionality defined by the MSOS code; an intermediate memory on the conversion card and connected to the bridge within which to write data supplied from the primary bus and from which to read data for writing to the at least one disk drive device, the intermediate memory having a relatively lesser latency for read and write operations than the latency for read and write operations of each disk drive device; the bridge further transferring signals defining data to be written to and read from the intermediate memory between the intermediate memory and the primary bus; and a battery power source on the conversion card connected to the intermediate memory to energize the intermediate memory to hold data written therein upon the occurrence of a predetermined error condition.