Editing Apple Desktop Bus (section)

== History ==

===AppleBus===
Early during the creation of the Macintosh computer, the engineering team had selected the fairly sophisticated [[Zilog SCC|Zilog 8530]] to supply serial communications. This was initially done to allow multiple devices to be plugged into a single port, using simple [[communication protocol]]s implemented inside the 8530 to allow them to send and receive data with the host computer. The idea was to allow multiple devices to be connected to a port, eliminating the need for many different types of ports or the use of [[expansion slot]]s.<ref name=history>{{cite journal|last=Oppenheimer |first=Alan |date=January 2004 |title=A History of Macintosh Networking |url=http://www.opendoor.com/nethistory/MacWorld2004/index.html |journal=MacWorld Expo |url-status=dead |archive-url=https://web.archive.org/web/20061016132614/http://www.opendoor.com/nethistory/MacWorld2004/index.html |archive-date=16 October 2006 }}</ref>

During development of this AppleBus system, computer networking became a vitally important feature of any computer system. With no card slots, the Macintosh was unable to easily add support for [[Ethernet]] or similar [[local area network]]ing standards. Work on AppleBus was re-directed to networking purposes, and was released in 1985 as the [[AppleTalk]] system. This left the Mac with the original single-purpose mouse and keyboard ports, and no general-purpose system for low-speed devices to use.<ref name=history/>

===Apple Desktop Bus===
The first system to use Apple Desktop Bus was the [[Apple IIGS|Apple II<small>GS</small>]] of 1986. It was used on all [[Mac (computer)|Apple Macintosh]] machines starting with the [[Macintosh II]] and [[Macintosh SE]]. Apple Desktop Bus was also used on later models of NeXT computers.<ref>{{Cite web |url=http://www.netbsd.org/ports/next68k/faq.html#adb |title="NetBSD/next68k: Frequently Asked Questions " |access-date=October 25, 2013 |archive-date=October 29, 2013 |archive-url=https://web.archive.org/web/20131029192412/http://www.netbsd.org/ports/next68k/faq.html#adb |url-status=live }}</ref> The vast majority of Apple Desktop Bus devices are for input, including [[trackball]]s, [[joystick]]s, [[graphics tablet]]s and similar devices. Special-purpose uses included [[software protection dongle]]s and even the [[Global Village Communication|TelePort modem]].

===Move to USB===
The first Macintosh to move on from Apple Desktop Bus was the [[iMac]] in 1998, which uses [[USB]] in its place. The last Apple computer to have an Apple Desktop Bus port is the [[Power Macintosh G3 (Blue and White)]] in 1999. PowerPC-based [[PowerBook]]s and [[iBook]]s still used the Apple Desktop Bus protocol in the internal interface with the built-in [[Computer keyboard|keyboard]] and [[touchpad]]. Subsequent models use a USB-based trackpad.