.\" $NetBSD: dmc.4,v 1.17 2017/08/01 11:11:17 wiz Exp $ .\" .\" Copyright (c) 1983, 1991, 1993 .\" The Regents of the University of California. 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. .\" 3. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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. .\" .\" from: @(#)dmc.4 8.1 (Berkeley) 6/5/93 .\" .Dd February 17, 2017 .Dt DMC 4 vax .Os .Sh NAME .Nm dmc .Nd .Tn DEC .Tn DMC-11 Ns / Ns Tn DMR-11 point-to-point serial communications device .Sh SYNOPSIS .Cd "dmc0 at uba0 csr 167600" .Sh DESCRIPTION NOTE: This driver has not been ported from .Bx 4.4 yet. .Pp The .Nm dmc interface provides access to a point-to-point communications device which runs at either 1 Mb/s or 56 Kb/s. .Tn DMC-11 Ns s communicate using the .Tn DEC DDCMP link layer protocol. .Pp The .Nm dmc interface driver also supports a .Tn DEC .Tn DMR-11 providing point-to-point communication running at data rates from 2.4 Kb/s to 1 Mb/s. .Tn DMR-11 Ns s are a more recent design and thus are preferred over .Tn DMC-11 Ns s . The .Dv NXMT and .Dv NRCV constants in the driver may be increased in this case, as the .Tn DMR can accept up to 64 transmit and receive buffers, as opposed to 7 for the .Tn DMC . .Pp The configuration flags specify how to set up the device, .Bl -column 1 description -offset indent .It 0 full duplex DDCMP (normal mode) .It 1 DDCMP Maintenance mode (generally useless) .It 2 DDCMP Half Duplex, primary station .It 3 DDCMP Half Duplex, secondary station .El The host's address must be specified with an .Dv SIOCSIFADDR .Xr ioctl 2 , and the destination address specified with a .Dv SIOCSIFDSTADDR .Xr ioctl 2 , before the interface will transmit or receive any packets. .Sh ROUTING The driver places a .Tn HOST entry in the kernel routing tables for the address given in the .Dv SIOCSIFDSTADDR .Xr ioctl 2 . To use the .Tn DMC as a link between local nets, the route to the remote net must be added manually with the .Xr route 8 command, or by the use of the routing process .Xr routed 8 on each end of the link. .Sh DIAGNOSTICS .Bl -diag .It dmc%d: bad control %o. A bad parameter was passed to the .Em dmcload routine. .It dmc%d: unknown address type %d. An input packet was received which contained a type of address unknown to the driver. .It DMC fatal error 0%o. A fatal error in .Tn DDMCP occurred, causing the device to be restarted. .It DMC soft error 0%o. A non-fatal error in .Tn DDMCP has occurred. .It dmc%d: af%d not supported. The interface was handed a message which has addresses formatted in an unsuitable address family. .El .Sh SEE ALSO .Xr inet 4 , .Xr vax/intro 4 .Sh HISTORY The .Nm driver appeared in .Bx 4.2 . .Sh BUGS The current version of the driver uses a link-level encapsulation so that multiple protocol types may be used. It is thus incompatible with earlier drivers, including the .Bx 4.2 version.