Advanced Technology Attachment (ATA)

Advanced Technology Attachment (ATA) is a standard physical interface for connecting storage devices within a computer. ATA allows hard disks and CD-ROMs to be internally connected to the motherboard and perform basic input/output functions.[1]

Computers can use ATA hard drives without a specific controller to support the drive. The motherboard must still support an ATA connection, but a separate card (such as a SCSI card for a SCSI hard drive) is not needed. Some different types of ATA standards include ATA-1, ATA-2 (a.k.a. Fast ATA), ATA-3, Ultra ATA (33 MBps maximum transfer rate), ATA/66 (66 MBps), and ATA/100 (100 MBps). The term IDE, or "Integrated Drive Electronics," is also used to refer to ATA drives. Sometimes (to add extra confusion to people buying hard drives), ATA drives are labeled as "IDE/ATA." Technically, ATA uses IDE technology, but the important thing to know is that they refer to the same thing.[2]

For PC Cards, any ATA compliant device should behave as a standard disk (for example ATA Flash cards). Technical Committee T13 of the National Committee on Information Technology Standards (NCITS), is responsible for all interface standards relating to the ATA interface including ATA and ATA with Packet Interface (ATAPI).[3]

The ATA standard is backward compatible, which means new ATA drives (excluding SATA) can be used with older ATA interfaces. Additionally, any new feature introduced is also found in all future releases. For example, ATA-4 has support for PIO modes 0, 1, 2, 3, and 4, even though these were first introduced in ATA-1 and ATA-2.[4]

There are several versions of ATA, all developed by the Small Form Factor (SFF) Committee:[5]

  • ATA: Known also as IDE, supports one or two hard drives, a 16-bit interface and PIO modes 0, 1 and 2.
  • ATA-2: Supports faster PIO modes (3 and 4) and multiword DMA modes (1 and 2). Also supports logical block addressing (LBA) and block transfers. ATA-2 is marketed as Fast ATA and Enhanced IDE (EIDE).
  • ATA-3:Minor revision to ATA-2.
  • Ultra-ATA: Also called Ultra-DMA, ATA-33, and DMA-33,supports multiword DMA mode 3 running at 33 MBps.
  • ATA/66:A version of ATA proposed by Quantum Corporation, and supported by Intel, that doubles ATA's throughput to 66 MBps.
  • ATA/100: An updated version of ATA/66 that increases data transfer rates to 100 MBps.
  • ATA also is called Parallel ATA. Contrast with Serial ATA.

Although the standard has always had the official name "ATA", marketing dictates dubbed an early version of the standard Integrated Drive Electronics (IDE), and the one following it Enhanced IDE (EIDE). Although these new names originated in branding convention and not as an official standard, the terms EIDE or E-IDE often appear interchangeably with IDE and ATA. With the introduction of Serial ATA around 2003, this configuration retroactively became renamed as Parallel ATA (P-ATA), referring to the method in which data travels over wires in this interface. The interface only worked with hard disks at first. Eventually, an extended standard came to work with a variety of other devices -- generally those using removable media. Principally, these devices include CD-ROM drives, tape drives, and large-capacity floppy drives such as the Zip drive and SuperDisk drive. The extension bears the name Advanced Technology Attachment Packet Interface (ATAPI), with the full standard now known as ATA/ATAPI. The movement from programmed input/output (PIO) to direct memory access (DMA) provided another important transition in the history of ATA. Of these methods for accessing and transferring data within computers, PIO proved inefficient, requiring a significant amount of oversight by the computer's CPU. This meant that systems based around ATA devices generally performed disk-related activities much more slowly than computers using SCSI or other interfaces. However, DMA (and later Ultra DMA or UDMA) greatly reduced the amount of processing time the CPU had to use in order to read and write the disks. ATA devices have suffered from a number of "barriers" in terms of how much data they can handle. However, new addressing systems and programming techniques have broken most of these barriers. Some of the ATA-specific barriers included: 504 MB, 32 GB, and 137 GB. A variety of other barriers have existed, usually due to poorly-written drivers and disk input/output layers in operating systems. Even the barriers listed above mostly came about due to poor BIOS implementations.[6]


  1. Definition - What does Advanced Technology Attachment (ATA) mean? Techopedia
  2. What is Advanced Technology Attachment (ATA)? Techterms
  3. ATA Standards Synchrotech
  4. Advanced Technology Attachment (ATA) Computerhope
  5. Versions of ATA Webopedia
  6. History of Advanced Technology Attachment (ATA) The David Lawrence Show

Further Reading