1.\" $NetBSD: dmc.4,v 1.17 2017/08/01 11:11:17 wiz Exp $ 2.\" 3.\" Copyright (c) 1983, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" from: @(#)dmc.4 8.1 (Berkeley) 6/5/93 31.\" 32.Dd February 17, 2017 33.Dt DMC 4 vax 34.Os 35.Sh NAME 36.Nm dmc 37.Nd 38.Tn DEC 39.Tn DMC-11 Ns / Ns Tn DMR-11 40point-to-point serial communications device 41.Sh SYNOPSIS 42.Cd "dmc0 at uba0 csr 167600" 43.Sh DESCRIPTION 44NOTE: This driver has not been ported from 45.Bx 4.4 46yet. 47.Pp 48The 49.Nm dmc 50interface provides access to a point-to-point communications 51device which runs at either 1 Mb/s or 56 Kb/s. 52.Tn DMC-11 Ns s 53communicate 54using the 55.Tn DEC DDCMP 56link layer protocol. 57.Pp 58The 59.Nm dmc 60interface driver also supports a 61.Tn DEC 62.Tn DMR-11 63providing point-to-point 64communication running at data rates from 2.4 Kb/s to 1 Mb/s. 65.Tn DMR-11 Ns s 66are a more recent design and thus are preferred over 67.Tn DMC-11 Ns s . 68The 69.Dv NXMT 70and 71.Dv NRCV 72constants in the driver may be increased in this case, 73as the 74.Tn DMR 75can accept up to 64 transmit and receive buffers, as opposed 76to 7 for the 77.Tn DMC . 78.Pp 79The configuration flags specify how to set up the device, 80.Bl -column 1 description -offset indent 81.It 0 full duplex DDCMP (normal mode) 82.It 1 DDCMP Maintenance mode (generally useless) 83.It 2 DDCMP Half Duplex, primary station 84.It 3 DDCMP Half Duplex, secondary station 85.El 86The host's address must be specified with an 87.Dv SIOCSIFADDR 88.Xr ioctl 2 , 89and the destination address specified with a 90.Dv SIOCSIFDSTADDR 91.Xr ioctl 2 , 92before the interface will transmit or receive any packets. 93.Sh ROUTING 94The driver places a 95.Tn HOST 96entry in the kernel routing tables for the 97address given in the 98.Dv SIOCSIFDSTADDR 99.Xr ioctl 2 . 100To use the 101.Tn DMC 102as a 103link between local nets, the route to the remote net must be added manually 104with the 105.Xr route 8 106command, or by the use of the routing process 107.Xr routed 8 108on each end of the link. 109.Sh DIAGNOSTICS 110.Bl -diag 111.It dmc%d: bad control %o. 112A bad parameter was passed to the 113.Em dmcload 114routine. 115.It dmc%d: unknown address type %d. 116An input packet was received which contained a type of 117address unknown to the driver. 118.It DMC fatal error 0%o. 119A fatal error in 120.Tn DDMCP 121occurred, causing the device to be restarted. 122.It DMC soft error 0%o. 123A non-fatal error in 124.Tn DDMCP 125has occurred. 126.It dmc%d: af%d not supported. 127The interface was handed a message which has 128addresses formatted in an unsuitable address family. 129.El 130.Sh SEE ALSO 131.Xr inet 4 , 132.Xr vax/intro 4 133.Sh HISTORY 134The 135.Nm 136driver appeared in 137.Bx 4.2 . 138.Sh BUGS 139The current version of the driver uses a link-level encapsulation 140so that multiple protocol types may be used. 141It is thus incompatible with earlier drivers, 142including the 143.Bx 4.2 144version. 145