Editing Parallel ATA (section)

=== IDE and ATA-1 ===
[[file:1992 80386 PC AMD 386DX-40 no onboard IDE floppy serial parallel sound video or network.jpg|thumb|left|Example of a 1992 80386 PC motherboard with nothing built in other than memory, keyboard, processor, cache, realtime clock, and slots. Such basic motherboards could have been outfitted with either the ST-506 or ATA interface, but usually not both. A single 2-drive ATA interface and a floppy interface was added to this system via the 16-bit ISA card]]

The first version of what is now called the ATA/ATAPI interface was developed by [[Western Digital]] under the name ''Integrated Drive Electronics'' (IDE). Together with [[Compaq]] (the initial customer), they worked with various disk drive manufacturers to develop and ship early products with the goal of remaining software compatible with the existing IBM PC hard drive interface.<ref>{{ cite web | title = System Architecture: a look at hard drives  |url=http://www.ackadia.com/computer/system-architecture/system-architecture-harddrive.php  |access-date=2008-07-25 | archive-url = https://web.archive.org/web/20060508023226/http://www.ackadia.com/computer/system-architecture/system-architecture-harddrive.php |archive-date = 2006-05-08|url-status=live}}</ref> The first such drives appeared internally in Compaq PCs in 1986<ref>{{ cite web | title = The PC Guide: Overview and History of the IDE/ATA Interface | url = http://www.pcguide.com/ref/hdd/if/ide/over.htm | archive-date = 2001-04-18 | archive-url = https://web.archive.org/web/20010418002244/http://www.pcguide.com:80/ref/hdd/if/ide/over.htm|access-date=2008-08-23 | author= Charles M. Kozierok | date = 2001-04-17 }}</ref><ref name="Milligan">{{ cite web |title=The History of CAM ATA | url = http://www.ata-atapi.com/histcam.html | access-date = 2008-08-27 | author = Gene Milligan | date = 2005-12-18 | archive-url = https://web.archive.org/web/20081004160101/http://www.ata-atapi.com/histcam.html | archive-date = 2008-10-04 | url-status = live }}</ref> and were first separately offered by [[Conner Peripherals]] as the CP342 in June 1987.<ref>{{ cite web | url = http://chmss.wikifoundry.com/page/Conner+CP341+Drive+%28ATA%2FIDE%29 | title = Conner CP341 Drive (ATA/IDE) |last=Burniece  |first=Tom  |date=July 21, 2011 | website = Wikifoundry | publisher = Computer History Museum Storage Special Interest Group | access-date = January 10, 2020 | archive-date = February 24, 2021 | archive-url = https://web.archive.org/web/20210224022517/http://chmss.wikifoundry.com/page/Conner+CP341+Drive+(ATA%2FIDE) | url-status = dead }}</ref>

The term ''Integrated Drive Electronics'' refers to the [[drive controller]] being integrated into the drive, as opposed to a separate controller situated at the other side of the connection cable to the drive. On an IBM PC compatible, [[CP/M]] machine, or similar, this was typically a card installed on a [[motherboard]]. The interface cards used to connect a parallel ATA drive to, for example, an [[Industry Standard Architecture|ISA Slot]], are not drive controllers: they are merely [[Host adapter|bridges between the host bus and the ATA interface]]. Since the original ATA interface is essentially just a 16-bit [[ISA bus]], the bridge was especially simple in case of an ATA connector being located on an ISA interface card. The integrated controller presented the drive to the host computer as an array of 512-byte blocks with a relatively simple command interface. This relieved the mainboard and interface cards in the host computer of the chores of stepping the disk head arm, moving the head arm in and out, and so on, as had to be done with earlier [[ST-506]] and [[Enhanced Small Disk Interface|ESDI]] hard drives. All of these low-level details of the mechanical operation of the drive were now handled by the controller on the drive itself. This also eliminated the need to design a single controller that could handle many different types of drives, since the controller could be unique for the drive. The host need only to ask for a particular sector, or block, to be read or written, and either accept the data from the drive or send the data to it.

The interface used by these drives was standardized in 1994 as ANSI standard X3.221-1994, ''AT Attachment Interface for Disk Drives''. After later versions of the standard were developed, this became known as "ATA-1".<ref>{{cite web |title=The PC Guide: ATA (ATA-1) |url=http://www.pcguide.com/ref/hdd/if/ide/stdATA-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 |title=AT Attachment Interface for Disk Drives (ATA-1) |publisher= Global Engineering Documents |year=1994}}</ref>

A short-lived, seldom-used implementation of ATA was created for the [[IBM Personal Computer XT|IBM XT]] and similar machines that used the 8-bit version of the ISA bus. It has been referred to as [[Industry Standard Architecture#XT-IDE|"XT-IDE"]], "XTA" or "XT Attachment".<ref>{{ cite web | title = Data Recovery and Hard Disk Drive Glossary of Terms | url = http://datarecoveryspecialist.com:80/glossaryofterms.htm | archive-url = https://web.archive.org/web/20120711155459/http://datarecoveryspecialist.com/glossaryofterms.htm | url-status = dead | archive-date = 2012-07-11 | access-date = 2012-07-11 | author = Independent Technology Service | year = 2008 }}</ref>