Abstract: A RAID storage device controller provides a host interface for interfacing the controller to a host system bus. The host interface is isolated from the attached storage devices, for example IDE disk drives, so that the actual attached drives are not limited in number or interface protocol. Various device ports can be implemented, and various RAID strategies, e.g., level 3 and level 5, can be used. In all the cases, the host interface provides a standard, uniform interface to the host, namely an ATA interface, and preferably a dual channel ATA interface. The host interface emulates the ATA single or dual channel interface and emulates one or two attached IDE devices per channel, regardless of the actual number of devices physically connected to the controller. Thus, for example, five or seven IDE drives can be deployed in RAID level 5 protocol without changing the standard BIOS in a PCI host machine. Thus the RAID controller is transparent relative to a standard dual channel ATA controller board.

Abstract: A RAID storage device controller provides a host interface for interfacing the controller to a host system bus. The host interface is isolated from the attached storage devices, for example IDE disk drives, so that the actual attached drives are not limited in number or interface protocol. Various device ports can be implemented, and various RAID strategies, e.g., level 3 and level 5, can be used. In all the cases, the host interface provides a standard, uniform interface to the host, namely an ATA interface, and preferably a dual channel ATA interface. The host interface emulates the ATA single or dual channel interface and emulates one or two attached IDE devices per channel, regardless of the actual number of devices physically connected to the controller. Thus, for example, five or seven IDE drives can be deployed in RAID level 5 protocol without changing the standard BIOS in a PCI host machine. Thus the RAID controller is transparent relative to a standard dual channel ATA controller board.