A group called the Small Form Factor committee (SFF) introduced ATAPI to be used for a variety of other devices that require functions beyond those necessary for hard disks.
The Small Form Factor committee approached this problem by defining ATAPI as part of the fourth generation of ATA.
This interfaces ATA with any device class for which a SCSI command set has been defined.
The SCSI commands and responses used by each class of ATAPI device (CD-ROM, tape, etc.)
ATAPI was adopted as part of ATA in INCITS 317-1998, AT Attachment with Packet Interface Extension (ATA/ATAPI-4).