1 files changed, 130 insertions, 0 deletions
diff --git a/static/netbsd/man4/man4.vax/en.4 b/static/netbsd/man4/man4.vax/en.4
new file mode 100644
index 00000000..5ca0b1b9
--- /dev/null
+++ b/static/netbsd/man4/man4.vax/en.4
@@ -0,0 +1,130 @@
+.\"	$NetBSD: en.4,v 1.15 2019/02/05 06:17:00 msaitoh Exp $
+.\"
+.\" Copyright (c) 1983, 1991, 1993
+.\"	The 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. 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: @(#)en.4	8.1 (Berkeley) 6/5/93
+.\"
+.Dd February 5, 2019
+.Dt EN 4 vax
+.Os
+.Sh NAME
+.Nm en
+.Nd Xerox 3 Mb/s Ethernet interface
+.Sh SYNOPSIS
+.Cd "en0 at uba0 csr 161000 vector enrint enxint encollide"
+.Sh DESCRIPTION
+NOTE: This driver has not been ported from
+.Bx 4.4
+yet.
+.Pp
+The
+.Nm en
+interface provides access to a 3 Mb/s Ethernet network.
+Due to limitations in the hardware,
+.Tn DMA
+transfers
+to and from the network must take place in the lower 64K bytes
+of the
+.Tn UNIBUS
+address space, and thus this must be among the first
+.Tn UNIBUS
+devices enabled after boot.
+.Pp
+Each of the host's network addresses
+is specified at boot time with an
+.Dv SIOCSIFADDR
+.Xr ioctl 2 .
+The station address is discovered by probing the on-board Ethernet
+address register, and is used to verify the protocol addresses.
+No packets will be sent or accepted until
+a network address is supplied.
+.Pp
+The interface software implements an exponential backoff algorithm
+when notified of a collision on the cable.
+This algorithm uses a 16-bit mask and the
+.Tn VAX-11 Ns 's
+interval timer in calculating a series
+of random backoff values.
+The algorithm is as follows:
+.Bl -enum -offset indent
+.It
+Initialize the mask to be all 1's.
+.It
+If the mask is zero, 16 retries have been made and we give
+up.
+.It
+Shift the mask left one bit and formulate a backoff by
+masking the interval timer with the mask (this is actually
+the two's complement of the value).
+.It
+Use the value calculated in step 3 to delay before retransmitting
+the packet.
+.El
+.Sh DIAGNOSTICS
+.Bl -diag
+.It en%d: output error.
+The hardware indicated an error on
+the previous transmission.
+.It en%d: send error.
+After 16 retransmissions using the
+exponential backoff algorithm described above, the packet
+was dropped.
+.It en%d: input error.
+The hardware indicated an error
+in reading a packet off the cable.
+.It en%d: can't handle af%d.
+The interface was handed
+a message with addresses formatted in an unsuitable address
+family; the packet was dropped.
+.El
+.Sh SEE ALSO
+.Xr inet 4 ,
+.Xr netintro 4
+.Sh HISTORY
+The
+.Nm
+driver appeared in
+.Bx 4.2 .
+.Sh BUGS
+The device has insufficient buffering to handle back to
+back packets.
+This makes use in a production environment painful.
+.Pp
+The hardware does word at a time
+.Tn DMA
+without byte swapping.
+To compensate, byte swapping of user data must either be done
+by the user or by the system.
+A kludge to byte swap only
+.Tn IP
+packets is provided if the
+.Dv ENF_SWABIPS
+flag is defined in
+the driver and set at boot time with an
+.Dv SIOCSIFFLAGS
+.Xr ioctl 2 .