Editing Parallel ATA (section)

=== ATAPI ===
{{main|ATA Packet Interface}}

ATA was originally designed for, and worked only with, [[hard disk drive]]s and devices that could emulate them. The introduction of ATAPI (ATA Packet Interface) by a group called the [[Small Form Factor committee]] (SFF) allowed ATA to be used for a variety of other devices that require functions beyond those necessary for hard disk drives. For example, any removable media device needs a "media eject" command, and a way for the host to determine whether the media is present, and these were not provided in the ATA protocol.

ATAPI is a protocol allowing the ATA interface to carry [[SCSI]] commands and responses; therefore, all ATAPI devices are actually "speaking SCSI" other than at the electrical interface. The SCSI commands and responses are embedded in "packets" (hence "ATA Packet Interface") for transmission on the ATA cable. This allows any device class for which a SCSI command set has been defined to be interfaced via ATA/ATAPI.

ATAPI devices are also "speaking ATA", as the ATA physical interface and protocol are still being used to send the packets. On the other hand, ATA hard drives and solid state drives do not use ATAPI.

ATAPI devices include CD-ROM and [[DVD-ROM]] drives, [[tape drive]]s, and large-capacity [[floppy disk|floppy]] drives such as the [[Zip drive]] and [[SuperDisk drive]]. Some early ATAPI devices were simply SCSI devices with an ATA/ATAPI to SCSI protocol converter added on.{{cn|date=May 2024}}

The SCSI commands and responses used by each class of ATAPI device (CD-ROM, tape, etc.) are described in other documents or specifications specific to those device classes and are not within ATA/ATAPI or the [[T13 subcommittee|T13]] committee's purview. <!-- ATAPI Packet Commands for Block Devices (SFF-8070i) ATAPI Packet Commands for CD-ROMs (SFF-8020i) --> One commonly used set is defined in the [[MultiMedia Commands|MMC]] SCSI command set.

ATAPI was adopted as part of ATA in INCITS 317-1998, ''AT Attachment with Packet Interface Extension (ATA/ATAPI-4)''.<ref>{{cite web |title=The PC Guide: SFF-8020 / ATA Packet Interface (ATAPI) |url=http://www.pcguide.com/ref/hdd/if/ide/stdATAPI-c.html |access-date=2008-08-23 |author=Charles M. Kozierok |date=2001-04-17}}</ref><ref>{{cite web |title=The PC Guide: ATA/ATAPI-4 |url=http://www.pcguide.com/ref/hdd/if/ide/stdATA4-c.html |access-date=2008-08-23 |author=Charles M. Kozierok |date=2001-04-17}}</ref><ref>{{cite book |last=Technical Committee T13 AT Attachment |url=http://www.t13.org/ |title=AT Attachment with Packet Interface Extension (ATA/ATAPI-4) |publisher=Global Engineering Documents |year=1998}}</ref>