ATA

A short form of Advanced Technology Attachment, ATA was approved on May 12, 1994, and is an interface used to connect hard drives, CD-ROM drives, and other drives. The first ATA interface is now commonly referred to as PATA, which is short for Parallel AT Attachment after the introduction of SATA. Today, almost all home computers use the ATA interface, including Apple computers, which use SATA.

ATA drives (excluding SATA) are backward-compatible, which means they can be used with older ATA interfaces. All future versions will also include any new features introduced. In spite of the fact that they were first introduced in ATA-1 and ATA-2, PIO modes 0, 1, 2, 3, and 4 are supported by ATA-4.

An explanation of each ATA standard is provided below to help you better understand the history of this interface and each standard's capabilities.

ATA, ATA-1, and IDE

The ATA was developed first by Control Data Corporation, Western Digital, and Compaq, and it had an 8-bit or 16-bit interface, a transfer rate of up to 8.3 MBps, and support for PIO modes 0, 1, and 2. ATA and ATA-1 are considered obsolete today.

ATA-2, EIDE, Fast ATA, Fast IDE, and Ultra ATA

ATA-2, or EIDE, and sometimes called Fast ATA or Fast IDE, is a standard approved by ANSI in 1996 under document number X3.279-1996. New features of ATA-2 include PIO modes 3 and 4, transfers of up to 16.6 MBps, DMA modes 1 and 2, and LBA support. It is also obsolete today.

ATA-3, and EIDE

The ATA-3 is a standard approved by ANSI in 1997 as document X3.298-1997. ATA-3 added new security features and the S.M.A.R.T feature.

ATAPI-4 and ATA/ATAPI-4

The ATA-4 standard was approved by ANSI on August 19, 1998, under document NCITS 317-1998. This version of ATA-4 includes ATAPI packet commands as well as UDMA / 33, which is also known as ultra-DMA / 33 or ultra-ATA / 33.

ATA-5 and ATA/ATAPI-5

The ATA-5 standard was approved by ANSI on December 13, 2000, under document NCITS 340-2000. In addition to supporting Ultra-DMA / 66, ATA-5 is capable of detecting 40 or 80-wire cables, and is capable of supporting data transfer rates of 66 MBps.

ATA-6 and ATA/ATAPI-6

The ATA-6 standard was approved by ANSI on May 16, 2001, under NCITS 347-2001. It supports Ultra-DMA / 100 and can transfer data at up to 100 MBps.

ATA layout

An ATA interface on a 3.5-inch disk drive has a 40-pin connector and can support up to two drives per interface. Each of the 40 pins on the ATA interface is described below.

Note

A 2.5-inch hard drive uses a 50-pin connector and PCMCIA utilizes a 68-pin connector.

Tip

See IDE (integrated drive electronics) definition for a visual representation of the cables, ports, and connections related to ATA.