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.svg) | |||
 The Apple Desktop Bus icon and an early Apple Desktop Bus keyboard | |||
| Type | Human input device interface | ||
|---|---|---|---|
| Production history | |||
| Designer | Apple Computer | ||
| Designed | 1986 | ||
| Manufacturer | Apple Computer Inc. | ||
| Produced | 1986 to 1999 | ||
| Superseded | RS-422/6522 keyboard and mouse | ||
| Superseded by | USB and FireWire (1998–1999) | ||
| General specifications | |||
| Hot pluggable | occasional support | ||
| External | yes | ||
| Pins | 4 | ||
| Connector | Mini-DIN | ||
| Data | |||
| Data signal | Bi-directional serial command stream | ||
| Bitrate |
125 kbit/s maximum (~10 kbit/s actual) | ||
| Max. devices |
16 maximum (~5 actual, 3 supported) | ||
| Protocol | Serial | ||
| Pinout | |||
 | |||
| Female socket from the front | |||
| Pin 1 | Apple Device Bus | Data | |
| Pin 2 | PSW | Power on | |
| Pin 3 | +5 V | +5 volts power | |
| Pin 4 | GND | Ground | |
| Same connector as S-Video | |||
Apple Desktop Bus (ADB) is a proprietary[1] bit-serial peripheral bus connecting low-speed devices to computers. It was introduced on the Apple IIGS in 1986 as a way to support low-cost devices like keyboards and mice, enabling them to be connected together in a daisy chain without the need for hubs or other devices. Apple Desktop Bus was quickly introduced on later Macintosh models, on later models of NeXT computers, and saw some other third-party use as well. Like the similar PS/2 connector used in many PC-compatibles at the time, Apple Desktop Bus was rapidly replaced by USB as that system became popular in the late 1990s; the last external Apple Desktop Bus port on an Apple product was in 1999, though it remained as an internal-only bus on some Mac models into the 2000s.
- ^ "ADB - The Untold Story: Space Aliens Ate My Mouse", "Licensing" section Archived December 27, 2016, at the Wayback Machine; see also this page's Patent section.