Advanced Technology Attachment

Advanced Technology Attachment (ATA), also referred to as Integrated Drive Electronics (IDE) is a disk drive interface standard based on the IBM PC 16-bit bus but also used on other personal computers. ATA specifies the power and data signal interfaces between the motherboard and the integrated disk controller and drive. The ATA "bus" only supports two devices - master and slave.

Form factor
ATA drives may use any physical interface the manufacturer requires, so long as an embedded translator is included with the proper ATA interface. 3.5-inch drives originally used a 40-pin connector while 2.5 and 1.8-inch mobile drives used a physically smaller 44-pin connector. ATA "controllers" are actually direct connections to the ISA bus. Since CompactFlash and PC Cards are also based on ISA, adapters exist for those form factors to IDE.

History
The first Integrated Drive Electronics (IDE) interface and drives were released by in 1986, developed with, , and then-upstart. Efforts to standardize the interface started in 1988; the first draft appeared in March 1989, and a finished version was sent to group X3T10, who named it "Advanced Technology Attachment" (ATA) for ratification in November 1990.

Standards and limitations
The X3T10 group later extended ATA to Advanced Technology Attachment Interface with Extensions (ATA-2), followed by ATA-3 through ATA-6. The ATA-7 standard became known as Serial ATA (SATA) 1.0. The older standards were retroactively referred to as "Parallel ATA" (PATA).

The first IDE specification used 22-bit addressing, which supported drive capacity up to 2 GB (like early HFS). Subsequent standards through ATA-5 (also known as Ultra ATA/66) used 28-bit logical block address, which supported recognizable drive space up to 128 GB. This required larger hard drives to be partitioned down to increments of 128 GB or less. ATA-6 (also known as Ultra ATA/100) introduced, which increased the limit to 144 petabytes (PB).

Apple Computer
The first Macintosh systems from Apple Computer to adopt an IDE hard drive instead of the long-used SCSI interface were the Quadra 630, which was released on July 15, 1994, followed by the PowerBook 150 on July 18, 1994. The first Macs to adopt the ATA-6 (Ultra ATA/100) implementation of IDE and overcome the 128 GB drive limit were the "Mirror Drive Doors" Power Mac G4, which was released on August 13, 2002, and the Aluminum PowerBook G4 models released on January 7, 2003.

Apple began transitioning to the use of SATA drives with the Power Mac G5, which was released on June 23, 2003. The last devices from Apple to use an IDE (or ATA) drive were the 1st-generation Apple TV, which was released on March 21, 2007, followed by the 6th-generation iPod classic on September 5, 2007.