This standard specifies the AT Attachment Interface between host systems using Automatic Direct Memory Access (ADMA) and storage devices. It provides a common link layer interface for systems manufacturers, system integrators, and software suppliers. The application environment for the AT Attachment Interface is any host system that has a PCI bus and storage devices contained within the processor enclosure. This standard maintains a high degree of compatibility with the AT Attachment with Packet Interface - 6 standard (ATA/ATAPI-6), INCITS 361-2002, and while specifying link-layer register definitions and usage information, is not intended to require changes to presently installed devices.