1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)dmc.4 8.1 (Berkeley) 06/05/93 7.\" 8.Dd 9.Dt DMC 4 vax 10.Os BSD 4.2 11.Sh NAME 12.Nm dmc 13.Nd 14.Tn DEC 15.Tn DMC-11 Ns / Tn DMR-11 16point-to-point communications device 17.Sh SYNOPSIS 18.Cd "device dmc0 at uba0 csr 167600 vector dmcrint dmcxint" 19.Sh DESCRIPTION 20The 21.Nm dmc 22interface provides access to a point-to-point communications 23device which runs at either 1 Mb/s or 56 Kb/s. 24.Tn DMC-11 Ns s 25communicate 26using the 27.Tn DEC DDCMP 28link layer protocol. 29.Pp 30The 31.Nm dmc 32interface driver also supports a 33.Tn DEC 34.Tn DMR-11 35providing point-to-point 36communication running at data rates from 2.4 Kb/s to 1 Mb/s. 37.Tn DMR-11 Ns s 38are a more recent design and thus are preferred over 39.Tn DMC-11 Ns s . 40The 41.Dv NXMT 42and 43.Dv NRCV 44constants in the driver may be increased in this case, 45as the 46.Tn DMR 47can accept up to 64 transmit and receive buffers, as opposed 48to 7 for the 49.Tn DMC . 50.Pp 51The configuration flags specify how to set up the device, 52.Bl -column xxx -offset indent 530 full duplex DDCMP (normal mode) 541 DDCMP Maintence mode (generally useless) 552 DDCMP Half Duplex, primary station 563 DDCMP Half Duplex, secondary station 57.El 58.Pp 59Several device error counters are available via 60.Xr adb 1 , 61for 62more information see the 63.Xr adb 64script 65.Pa /usr/lib/adb/dmcstats , 66or the 67.Tn DMC-11 68technical manual. 69.Pp 70The host's address must be specified with an 71.Dv SIOCSIFADDR 72.Xr ioctl 2 , 73and the destination address specified with a 74.Dv SIOCSIFDSTADDR 75.Xr ioctl , 76before the interface will transmit or receive any packets. 77.Sh ROUTING 78The driver places a 79.Tn HOST 80entry in the kernel routing tables for the 81address given in the 82.Dv SIOCSIFDSTADDR 83.Xr ioctl. 84To use the 85.Tn DMC 86as a 87link between local nets, the route to the remote net must be added manually 88with the 89.Xr route 8 90command, or by the use of the routing process 91.Xr routed 8 92on each end of the link. 93.Sh DIAGNOSTICS 94.Bl -diag 95.It dmc%d: bad control %o. 96A bad parameter was passed to the 97.Em dmcload 98routine. 99.Pp 100.It dmc%d: unknown address type %d. 101An input packet was received which contained a type of 102address unknown to the driver. 103.Pp 104.It DMC fatal error 0%o. 105A fatal error in 106.Tn DDMCP 107occurred, causing the device to be restarted. 108.Pp 109.It DMC soft error 0%o. 110A non-fatal error in 111.Tn DDMCP 112has occurred. 113.Pp 114.It dmc%d: af%d not supported. 115The interface was handed a message which has 116addresses formatted in an unsuitable address family. 117.El 118.Sh SEE ALSO 119.Xr intro 4 , 120.Xr inet 4 121.Sh HISTORY 122The 123.Nm 124driver appeared in 125.Bx 4.2 . 126.Sh BUGS 127The current version of the driver uses a link-level encapsulation 128so that multiple protocol types may be used. 129It is thus incompatible with earlier drivers, 130including the 131.Bx 4.2 132version. 133