1*61595Sbostic.\" Copyright (c) 1985, 1991, 1993 2*61595Sbostic.\" The Regents of the University of California. All rights reserved. 324030Smckusick.\" 447674Scael.\" %sccs.include.redist.man% 524030Smckusick.\" 6*61595Sbostic.\" @(#)dhu.4 8.1 (Berkeley) 06/05/93 747674Scael.\" 847674Scael.Dd 947674Scael.Dt DHU 4 vax 1047674Scael.Os BSD 4.3 1147674Scael.Sh NAME 1247674Scael.Nm dhu 1347674Scael.Nd 1447674Scael.Tn DHU-11 1547674Scaelcommunications multiplexer 1647674Scael.Sh SYNOPSIS 1747674Scael.Cd "device dhu0 at uba0 csr 0160440 vector dhurint dhuxint" 1847674Scael.Sh DESCRIPTION 1947674ScaelA 2047674Scael.Tn DHU-11 2147674Scaelprovides 16 communication lines. 2247674Scael.Pp 2347674ScaelAn optional argument 2447674Scael.Ar flags 2547674Scaelmay be supplied with the device specification 2647674Scaelin the config file indicating 2747674Scaelthat the line corresponding to 2847674Scaelbit number 2947674Scael.Ar i 3047674Scaelis not properly 3147674Scaelconnected, and should be treated as hard-wired with carrier 3247674Scaelalways present. Thus specifying 3347674Scael.Ql flags 0x0004 3447674Scaelfor 3547674Scael.Li dhu0 3647674Scaelwould cause line 3747674Scael.Pa ttyS2 3847674Scaelto be treated in this way. 3947674Scael.Pp 4047674ScaelNormal I/O 4147674Scaelcontrol parameters for individual lines are managed by 4247674Scael.Xr ioctl 2 4347674Scaelcalls. 4447674ScaelIndividual 4547674Scael.Tn DHU-11 4647674Scaellines may be configured to run at any of 13 speeds 4747674Scael(50, 200 and 38400 baud are not available); 4847674Scaelthe speed may be set via 4947674Scael.Xr getty 8 5047674Scaelor 5147674Scael.Xr stty 1 5247674Scaelor may be communicated by other programs which 5347674Scaelutilize 5447674Scael.Xr ioctl 5547674Scaelsuch as 5647674Scael.Xr ifcongif 8 , 5724030Smckusicksee 5847674Scael.Xr tty 4 . 5947674Scael.Pp 6047674ScaelThe 6147674Scael.Tn DHU-11 6247674Scaeldriver normally uses input silos 6324030Smckusickand delays receiver interrupts by 20 milliseconds 6424030Smckusickrather than taking an interrupt on each input character. 6547674Scael.Sh FILES 6647674Scael.Bl -tag -width /dev/tty[S-Z][0-9a-f]xx -compact 6747674Scael.It Pa /dev/tty[S-Z][0-9a-f] 6847674Scael.El 6947674Scael.Sh DIAGNOSTICS 7047674Scael.Bl -diag 7147674Scael.It dhu(%d,%d): NXM fault. 7247674ScaelNo response from 7347674Scael.Tn UNIBUS 7447674Scaelon a 7547674Scael.Tn DMA 7647674Scaeltransfer 7747674Scaelwithin a timeout period. This is often followed by a 7847674Scael.Tn UNIBUS 7947674Scaeladapter 8047674Scaelerror. This occurs most frequently when the 8147674Scael.Tn UNIBUS 8247674Scaelis heavily loaded 8347674Scaeland when devices which hog the bus (such as 8447674Scael.Tn RK07 Ns s ) 8547674Scaelare present. 8624030SmckusickIt is not serious. 8747674Scael.Pp 8847674Scael.It dhu%d: silo overflow. 8947674ScaelThe character input silo overflowed 9024030Smckusickbefore it could be serviced. This can happen if a hard error occurs 9147674Scaelwhen the 9247674Scael.Tn CPU 9347674Scaelis running with elevated priority, as the system may 9424030Smckusickthen print a message on the console with interrupts disabled. 9547674Scael.El 9647674Scael.Sh NOTES 9724030SmckusickThe driver currently does not make full use of the hardware 9847674Scaelcapabilities of the 9947674Scael.Tn DHU-11 , 10047674Scaelfor dealing with 10147674Scael.Tn XON/XOFF 10247674Scaelflow-control or hard-wired 10324030Smckusicklines for example. 10447674Scael.Pp 10547674ScaelAlthough the devices are not the same, a 10647674Scael.Tn DHU-11 10747674Scaelcan convince the 10847674Scael.Tn DH-11 10947674Scaelautoconfiguration code that it is a 11047674Scael.Tn DH-11 . 11147674Scael.Pp 11224030SmckusickThe 4 40-way cables are a pain. 11347674Scael.Sh SEE ALSO 11447674Scael.Xr tty 4 11547674Scael.Sh HISTORY 11647674ScaelThe 11747674Scael.Nm 11847674Scaeldriver appeared in 11947674Scael.Bx 4.3 . 120