.\" $OpenBSD: adb.4,v 1.14 2006/01/10 07:38:28 miod Exp $
.\"
.\" Copyright (c) 2001 Peter Philipp
.\" Copyright (c) 1997 Colin Wood
.\" All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
.\" are met:
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.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"      This product includes software developed by Colin Wood
.\"      for the NetBSD Project.
.\" 4. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission
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.Dd July 30, 2001
.Dt ADB 4 macppc
.Os
.Sh NAME
.Nm adb
.Nd Apple Desktop Bus driver
.Sh SYNOPSIS
.Cd "adb0 at macobio?"
.Cd "abtn* at adb?"
.Cd "akbd* at adb?"
.Cd "ams* at adb?"
.Cd "apm0 at adb?"
.Cd "pi2c0 at adb?"
.Sh DESCRIPTION
The Apple Desktop Bus
.Pq Tn ADB
is the single-master, multiple-slave, low-speed serial bus
interface used by Macintosh computers to connect input devices
such as keyboards, mice, trackballs, and graphics tablets
to the machine.
.Pp
Originally developed for the Mac68K port, the
.Nm
driver was heavily modified when it was ported to the PowerPC architecture.
During this port it seems that the original
.Nm
event device was split into many smaller subsystems, namely:
.Pp
.Bl -enum -compact
.It
Apple Keyboard driver
.Pq Xr akbd 4 .
.It
Apple Mouse Support driver
.Pq Xr ams 4 .
.El
.Pp
New
.Nm
devices such as the Apple Brightness / Volume Control Button
.Pq Xr abtn 4 ,
some energy control
.Pq Xr apm 4 ,
and I2C controller
.Pq Xr pi2c 4
were added to the PowerPC port later to complement the ADB system.
.Sh SEE ALSO
.Xr abtn 4 ,
.Xr akbd 4 ,
.Xr ams 4 ,
.Xr apm 4 ,
.Xr intro 4 ,
.Xr pi2c 4
.Sh HISTORY
The
.Nm
interface first appeared in
.Nx 0.9 .
It has been under development ever since.
The original
.Nm adb
manpage was written by Colin Wood for
.Nx Ns / Ns Mac68K.
.Sh AUTHORS
Original ADB support was written by Bradley A. Grantham.
The direct ADB routines were written by John P. Wittkoski.