1.\" $NetBSD: rtfps.4,v 1.9 2003/08/07 10:31:03 agc Exp $ 2.\" 3.\" Copyright (c) 1990, 1991 The Regents of the University of California. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to Berkeley by 7.\" the Systems Programming Group of the University of Utah Computer 8.\" Science Department. 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. Neither the name of the University nor the names of its contributors 18.\" may be used to endorse or promote products derived from this software 19.\" without specific prior written permission. 20.\" 21.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.\" from: @(#)dca.4 5.2 (Berkeley) 3/27/91 34.\" from: Id: com.4,v 1.1 1993/08/06 11:19:07 cgd Exp 35.\" 36.Dd August 7, 1994 37.Dt RTFPS 4 38.Os 39.Sh NAME 40.Nm rtfps 41.Nd multiplexing serial communications interface 42.Sh SYNOPSIS 43.Cd "rtfps0 at isa? port 0x1230 irq 10" 44.Cd "com2 at rtfps0 slave 0" 45.Cd "com3 at rtfps0 slave 1" 46.Cd "com4 at rtfps0 slave 2" 47.Cd "com5 at rtfps0 slave 3" 48.Sh DESCRIPTION 49The 50.Nm rtfps 51driver provides support for IBM RT PC boards that multiplex together up to four 52.Tn EIA 53.Tn RS-232C 54.Pf ( Tn CCITT 55.Tn V.28 ) 56or 57.Tn RS-422A 58communications interfaces. 59.Pp 60Each 61.Nm 62device is the master device for up to four 63.Nm com 64devices. The kernel configuration specifies these 65.Nm com 66devices as slave devices of the 67.Nm 68device, as shown in the synopsis. 69The 70.Tn port 71specification for the 72.Nm 73device is used to compute the base addresses for the 74.Nm com 75subdevices. 76.Sh FILES 77.Bl -tag -width Pa 78.It Pa /dev/tty0? 79.El 80.Sh SEE ALSO 81.Xr com 4 82.Sh HISTORY 83The 84.Nm 85driver was written by Charles Hannum, based on the 86.Nm ast 87driver. 88.Sh BUGS 89The 90.Nm 91driver is unlikely to work on non-EISA and non-PCI machines. The ISA 92bus only asserts 10 I/O address lines, and this is not enough. 93.Pp 94Even on EISA and PCI machines, some address conflicts have been observed. 95On one machine, the second port always conflicted with something (though 96it's not clear what) and caused strange results. Disabling the second 97port in the kernel config allowed the other three ports to function 98correctly. 99