A disk array includes a mainframe chassis conforming to standard SCSI disk drive mechanical form factors, and a mother board and a RAID controller within the chassis. The chassis includes a pivotable access door shock absorber mounted on an inside surface of the door which permits electronic modules to be placed within the chassis, and which helps to control mechanical shock between the chassis and the enclosed electronic modules. The mother board interconnects electrical signals between the electronic modules, at least some of which comprise disk drives forming a redundant array of independent, or inexpensive, disks (RAID). One of the electronic modules is a secondary power supply module which is connectable to the mother board. The RAID controller is electrically connected to a system host power supply and a host interface bus, and through the RAID controller the mother board interconnects all the electrical signals between the system host power supply and the host interface bus with the secondary power supply module and the RAID disk drives.