DMC(4) NetBSD Programmer's Manual (VAX Architecture) DMC(4) NNAAMMEE ddmmcc - DEC DMC-11/ DMR-11 point-to-point communications device SSYYNNOOPPSSIISS ddeevviiccee ddmmcc00 aatt uubbaa00 ccssrr 116677660000 vveeccttoorr ddmmccrriinntt ddmmccxxiinntt DDEESSCCRRIIPPTTIIOONN The ddmmcc interface provides access to a point-to-point communications de- vice which runs at either 1 Mb/s or 56 Kb/s. DMC-11s communicate using the DEC DDCMP link layer protocol. The ddmmcc interface driver also supports a DEC DMR-11 providing point-to- point communication running at data rates from 2.4 Kb/s to 1 Mb/s. DMR-11s are a more recent design and thus are preferred over DMC-11s. The NXMT and NRCV constants in the driver may be increased in this case, as the DMR can accept up to 64 transmit and receive buffers, as opposed to 7 for the DMC. The configuration flags specify how to set up the device, 0 full duplex DDCMP (normal mode) 1 DDCMP Maintence mode (generally useless) 2 DDCMP Half Duplex, primary station 3 DDCMP Half Duplex, secondary station Several device error counters are available via adb(1), for more infor- mation see the adb script _/_u_s_r_/_l_i_b_/_a_d_b_/_d_m_c_s_t_a_t_s, or the DMC-11 technical manual. The host's address must be specified with an SIOCSIFADDR ioctl(2), and the destination address specified with a SIOCSIFDSTADDR ioctl, before the interface will transmit or receive any packets. RROOUUTTIINNGG The driver places a HOST entry in the kernel routing tables for the ad- dress given in the SIOCSIFDSTADDR ioctl. To use the DMC as a link be- tween local nets, the route to the remote net must be added manually with the route(8) command, or by the use of the routing process routed(8) on each end of the link. DDIIAAGGNNOOSSTTIICCSS ddmmcc%%dd:: bbaadd ccoonnttrrooll %%oo.. A bad parameter was passed to the _d_m_c_l_o_a_d rou- tine. ddmmcc%%dd:: uunnkknnoowwnn aaddddrreessss ttyyppee %%dd.. An input packet was received which con- tained a type of address unknown to the driver. DDMMCC ffaattaall eerrrroorr 00%%oo.. A fatal error in DDMCP occurred, causing the device to be restarted. DDMMCC ssoofftt eerrrroorr 00%%oo.. A non-fatal error in DDMCP has occurred. ddmmcc%%dd:: aaff%%dd nnoott ssuuppppoorrtteedd.. The interface was handed a message which has addresses formatted in an unsuitable address family. SSEEEE AALLSSOO intro(4), inet(4) HHIISSTTOORRYY The ddmmcc driver appeared in 4.2BSD. BBUUGGSS The current version of the driver uses a link-level encapsulation so that multiple protocol types may be used. It is thus incompatible with earli- er drivers, including the 4.2BSD version. 4.2 Berkeley Distribution December 18, 1995 2