.\" $OpenBSD: addcom.4,v 1.4 2003/06/02 18:51:33 jason Exp $ .\" .\" Copyright (c) 2001 Jason L. Wright (jason@thought.net) .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" 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. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED .\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE .\" DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, .\" INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES .\" (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR .\" SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, .\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN .\" ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE .\" POSSIBILITY OF SUCH DAMAGE. .\" .\" .Dd July 16, 2001 .Dt ADDCOM 4 .Os .Sh NAME .Nm addcom .Nd multiplexing serial communications interface .Sh SYNOPSIS .Cd "addcom0 at isa? port 0x108 irq 5" .Cd "com* at addcom? slave ?" or .Cd "pccom* at addcom? slave ?" .Sh DESCRIPTION The .Nm driver provides support for Addonics FlexPort 8/S (and probably FlexPort 4/S) boards that multiplex together up to eight (or four) .Tn EIA .Tn RS-232C .Pf ( Tn CCITT .Tn V.28 ) communications interfaces. .Pp Each .Nm device is the master device for up to eight .Nm com devices. The kernel configuration specifies these .Nm com devices as slave devices of the .Nm device, as shown in the synopsis. The slave ID given for each .Nm com device determines which bit in the interrupt multiplexing register is tested to find interrupts for that device. The .Tn port specification for the .Nm device is used to compute the base addresses for the .Nm com subdevices. The port for the interrupt multiplexing register is fixed, so it is doubtful that more than one .Nm can be used in a machine. .Sh FILES .Bl -tag -width Pa .It Pa /dev/tty?? .El .Sh SEE ALSO .Xr com 4 , .Xr intro 4 , .Xr isa 4 .Sh HISTORY .Ox support for .Nm devices first appeared in .Ox 3.0 .