scope:

This part of ISO/IEC 24739 specifies the AT Attachment Interface between host systems and storage devices. It provides a common attachment interface for systems manufacturers, system integrators, software suppliers and suppliers of intelligent storage devices. ISO/IEC 24739-1 defines the register delivered commands used by devices implementing the standard.

ISO/IEC 24739-2 defines the connectors and cables for physical interconnection between host and storage device, the electrical and logical characteristics of the interconnecting signals and the protocols for the transporting of commands, data and status over the interface for the parallel interface. ISO/IEC 24739-3 defines the connectors and cables for physical interconnection between host and storage device, the electrical and logical characteristics of the interconnecting signals and the protocols for the transporting of commands, data and status over the interface for the serial interface. Figure 1 shows the relationship of these documents. For devices implementing the PACKET command feature set, additional command layer standards are listed in Table 1 and described in Clause 2.

This standard maintains compatibility with the AT Attachment with packet interface-6 standard (ATA/ATAPI-6), ANSI INCITS 361-2002, and while providing additional functions, is not intended to require changes to presently installed devices or existing software.