1.\" 2.\" Copyright (c) 1990, 1991 The Regents of the University of California. 3.\" All rights reserved. 4.\" 5.\" This code is derived from software contributed to Berkeley by 6.\" the Systems Programming Group of the University of Utah Computer 7.\" Science Department. 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. All advertising materials mentioning features or use of this software 17.\" must display the following acknowledgement: 18.\" This product includes software developed by the University of 19.\" California, Berkeley and its contributors. 20.\" 4. Neither the name of the University nor the names of its contributors 21.\" may be used to endorse or promote products derived from this software 22.\" without specific prior written permission. 23.\" 24.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34.\" SUCH DAMAGE. 35.\" 36.\" from: @(#)dca.4 5.2 (Berkeley) 3/27/91 37.\" from: Id: com.4,v 1.1 1993/08/06 11:19:07 cgd Exp 38.\" $Id: rtfps.4,v 1.2 1994/08/11 22:18:50 mycroft Exp $ 39.\" 40.Dd August 7, 1994 41.Dt RTFPS 4 i386 42.Os NetBSD 1.0 43.Sh NAME 44.Nm rtfps 45.Nd 46multiplexing serial communications interface 47.Sh SYNOPSIS 48.Cd "master rtfps0 at isa? port 0x1230 irq 10" 49.Cd "device com2 at rtfps0 slave 0" 50.Cd "device com3 at rtfps0 slave 1" 51.Cd "device com4 at rtfps0 slave 2" 52.Cd "device com5 at rtfps0 slave 3" 53.Sh DESCRIPTION 54The 55.Nm rtfps 56driver provides support for IBM RT PC boards that multiplex together up to four 57.Rn EIA 58.Tn RS-232C 59.Pf ( Tn CCITT 60.Tn V.28 ) 61or 62.Tn RS-422A 63communications interfaces. 64.Pp 65Each 66.Nm 67device is the master device for up to four 68.Nm com 69devices. The kernel configuration specifies these 70.Nm com 71devices as slave devices of the 72.Nm 73device, as shown in the synopsis. The kernel configuration specification 74for each slave 75.Nm com 76device can optionally omit the 77.Tn port 78specification, in which case the slaves are assumed to be at 79sequential addresses. The 80.Tn port 81specification for the 82.Nm 83device is taken as the default port for the first slave 84.Nm com 85device. 86.Sh FILES 87.Bl -tag -width Pa 88.It Pa /dev/tty0? 89.El 90.Sh SEE ALSO 91.Xr com 4 92.Sh HISTORY 93The 94.Nm 95driver was written by Charles Hannum, based on the 96.Nm ast 97driver. 98.Sh BUGS 99The 100.Nm 101driver is unlikely to work on non-EISA and non-PCI machines. The ISA 102bus only asserts 10 I/O address lines, and this is not enough. 103.Pp 104Even on EISA and PCI machines, some address conflicts have been observed. 105On one machine, the second port always conflicted with something (though 106it's not clear what) and caused strange results. Disabling the second 107port in the kernel config allowed the other three ports to function 108correctly. 109