initial import of NetBSD tree

1 files changed, 146 insertions, 0 deletions

diff --git a/share/man/man4/man4.vax/dhu.4 b/share/man/man4/man4.vax/dhu.4
new file mode 100644
index 00000000000..b14c5bbd241
--- /dev/null
+++ b/share/man/man4/man4.vax/dhu.4
@@ -0,0 +1,146 @@
+.\" Copyright (c) 1985, 1991 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. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"	This product includes software developed by the University of
+.\"	California, Berkeley and its contributors.
+.\" 4. 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: @(#)dhu.4	6.3 (Berkeley) 3/27/91
+.\"	$Id: dhu.4,v 1.1 1995/10/18 08:44:34 deraadt Exp $
+.\"
+.Dd March 27, 1991
+.Dt DHU 4 vax
+.Os BSD 4.3
+.Sh NAME
+.Nm dhu
+.Nd
+.Tn DHU-11
+communications multiplexer
+.Sh SYNOPSIS
+.Cd "device dhu0 at uba0 csr 0160440 vector dhurint dhuxint"
+.Sh DESCRIPTION
+A
+.Tn DHU-11
+provides 16 communication lines.
+.Pp
+An optional argument
+.Ar flags
+may be supplied with the device specification
+in the config file indicating
+that the line corresponding to
+bit number
+.Ar i
+is not properly
+connected, and should be treated as hard-wired with carrier
+always present.  Thus specifying
+.Ql flags 0x0004
+for
+.Li dhu0
+would cause line
+.Pa ttyS2
+to be treated in this way.
+.Pp
+Normal I/O
+control parameters for individual lines are managed by
+.Xr ioctl 2
+calls.
+Individual
+.Tn DHU-11
+lines may be configured to run at any of 13 speeds
+(50, 200 and 38400 baud are not available);
+the speed may be set via
+.Xr getty 8
+or
+.Xr stty 1
+or may be communicated by other programs which
+utilize
+.Xr ioctl
+such as
+.Xr ifcongif 8 ,
+see
+.Xr tty 4 .
+.Pp
+The
+.Tn DHU-11
+driver normally uses input silos
+and delays receiver interrupts by 20 milliseconds
+rather than taking an interrupt on each input character.
+.Sh FILES
+.Bl -tag -width /dev/tty[S-Z][0-9a-f]xx -compact
+.It Pa /dev/tty[S-Z][0-9a-f]
+.El
+.Sh DIAGNOSTICS
+.Bl -diag
+.It dhu(%d,%d): NXM fault.
+No response from
+.Tn UNIBUS
+on a
+.Tn DMA
+transfer
+within a timeout period.  This is often followed by a
+.Tn UNIBUS
+adapter
+error.  This occurs most frequently when the
+.Tn UNIBUS
+is heavily loaded
+and when devices which hog the bus (such as
+.Tn RK07 Ns s )
+are present.
+It is not serious.
+.Pp
+.It dhu%d: silo overflow.
+The character input silo overflowed
+before it could be serviced.  This can happen if a hard error occurs
+when the
+.Tn CPU
+is running with elevated priority, as the system may
+then print a message on the console with interrupts disabled.
+.El
+.Sh NOTES
+The driver currently does not make full use of the hardware
+capabilities of the
+.Tn DHU-11 ,
+for dealing with
+.Tn XON/XOFF
+flow-control or hard-wired
+lines for example.
+.Pp
+Although the devices are not the same, a
+.Tn DHU-11
+can convince the
+.Tn DH-11
+autoconfiguration code that it is a
+.Tn DH-11 .
+.Pp
+The 4 40-way cables are a pain.
+.Sh SEE ALSO
+.Xr tty 4
+.Sh HISTORY
+The
+.Nm
+driver appeared in
+.Bx 4.3 .