1*47674Scael.\" Copyright (c) 1985, 1991 Regents of the University of California. 2*47674Scael.\" All rights reserved. 324030Smckusick.\" 4*47674Scael.\" %sccs.include.redist.man% 524030Smckusick.\" 6*47674Scael.\" @(#)dhu.4 6.3 (Berkeley) 03/27/91 7*47674Scael.\" 8*47674Scael.Dd 9*47674Scael.Dt DHU 4 vax 10*47674Scael.Os BSD 4.3 11*47674Scael.Sh NAME 12*47674Scael.Nm dhu 13*47674Scael.Nd 14*47674Scael.Tn DHU-11 15*47674Scaelcommunications multiplexer 16*47674Scael.Sh SYNOPSIS 17*47674Scael.Cd "device dhu0 at uba0 csr 0160440 vector dhurint dhuxint" 18*47674Scael.Sh DESCRIPTION 19*47674ScaelA 20*47674Scael.Tn DHU-11 21*47674Scaelprovides 16 communication lines. 22*47674Scael.Pp 23*47674ScaelAn optional argument 24*47674Scael.Ar flags 25*47674Scaelmay be supplied with the device specification 26*47674Scaelin the config file indicating 27*47674Scaelthat the line corresponding to 28*47674Scaelbit number 29*47674Scael.Ar i 30*47674Scaelis not properly 31*47674Scaelconnected, and should be treated as hard-wired with carrier 32*47674Scaelalways present. Thus specifying 33*47674Scael.Ql flags 0x0004 34*47674Scaelfor 35*47674Scael.Li dhu0 36*47674Scaelwould cause line 37*47674Scael.Pa ttyS2 38*47674Scaelto be treated in this way. 39*47674Scael.Pp 40*47674ScaelNormal I/O 41*47674Scaelcontrol parameters for individual lines are managed by 42*47674Scael.Xr ioctl 2 43*47674Scaelcalls. 44*47674ScaelIndividual 45*47674Scael.Tn DHU-11 46*47674Scaellines may be configured to run at any of 13 speeds 47*47674Scael(50, 200 and 38400 baud are not available); 48*47674Scaelthe speed may be set via 49*47674Scael.Xr getty 8 50*47674Scaelor 51*47674Scael.Xr stty 1 52*47674Scaelor may be communicated by other programs which 53*47674Scaelutilize 54*47674Scael.Xr ioctl 55*47674Scaelsuch as 56*47674Scael.Xr ifcongif 8 , 5724030Smckusicksee 58*47674Scael.Xr tty 4 . 59*47674Scael.Pp 60*47674ScaelThe 61*47674Scael.Tn DHU-11 62*47674Scaeldriver normally uses input silos 6324030Smckusickand delays receiver interrupts by 20 milliseconds 6424030Smckusickrather than taking an interrupt on each input character. 65*47674Scael.Sh FILES 66*47674Scael.Bl -tag -width /dev/tty[S-Z][0-9a-f]xx -compact 67*47674Scael.It Pa /dev/tty[S-Z][0-9a-f] 68*47674Scael.El 69*47674Scael.Sh DIAGNOSTICS 70*47674Scael.Bl -diag 71*47674Scael.It dhu(%d,%d): NXM fault. 72*47674ScaelNo response from 73*47674Scael.Tn UNIBUS 74*47674Scaelon a 75*47674Scael.Tn DMA 76*47674Scaeltransfer 77*47674Scaelwithin a timeout period. This is often followed by a 78*47674Scael.Tn UNIBUS 79*47674Scaeladapter 80*47674Scaelerror. This occurs most frequently when the 81*47674Scael.Tn UNIBUS 82*47674Scaelis heavily loaded 83*47674Scaeland when devices which hog the bus (such as 84*47674Scael.Tn RK07 Ns s ) 85*47674Scaelare present. 8624030SmckusickIt is not serious. 87*47674Scael.Pp 88*47674Scael.It dhu%d: silo overflow. 89*47674ScaelThe character input silo overflowed 9024030Smckusickbefore it could be serviced. This can happen if a hard error occurs 91*47674Scaelwhen the 92*47674Scael.Tn CPU 93*47674Scaelis running with elevated priority, as the system may 9424030Smckusickthen print a message on the console with interrupts disabled. 95*47674Scael.El 96*47674Scael.Sh NOTES 9724030SmckusickThe driver currently does not make full use of the hardware 98*47674Scaelcapabilities of the 99*47674Scael.Tn DHU-11 , 100*47674Scaelfor dealing with 101*47674Scael.Tn XON/XOFF 102*47674Scaelflow-control or hard-wired 10324030Smckusicklines for example. 104*47674Scael.Pp 105*47674ScaelAlthough the devices are not the same, a 106*47674Scael.Tn DHU-11 107*47674Scaelcan convince the 108*47674Scael.Tn DH-11 109*47674Scaelautoconfiguration code that it is a 110*47674Scael.Tn DH-11 . 111*47674Scael.Pp 11224030SmckusickThe 4 40-way cables are a pain. 113*47674Scael.Sh SEE ALSO 114*47674Scael.Xr tty 4 115*47674Scael.Sh HISTORY 116*47674ScaelThe 117*47674Scael.Nm 118*47674Scaeldriver appeared in 119*47674Scael.Bx 4.3 . 120