4.3BSD/usr/man/man4/vp.4

.\" Copyright (c) 1980 Regents of the University of California.
.\" All rights reserved.  The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
.\"
.\"	@(#)vp.4	6.2 (Berkeley) 5/14/86
.\"
.TH VP 4 "May 14, 1986"
.UC 4
.SH NAME
vp \- Versatec interface
.SH SYNOPSIS
.B "device vp0 at uba0 csr 0177510 vector vpintr vpintr"
.SH DESCRIPTION
The Versatec printer/plotter is normally used with the
line printer system.
This description is designed for those who wish to drive the Versatec directly.
.PP
To use the Versatec yourself, you must realize that you cannot open the
device,
.I /dev/vp0
if there is a daemon active.
You can see if there is a daemon active by doing a
.IR lpq (1),
and seeing if there are any files being sent.
Printing should be turned off using
.IR lpc (8).
.PP
To set the Versatec into plot mode you should include
.RI < sys/vcmd.h >
and use the
.IR ioctl (2)
call
.IP
ioctl(fileno(vp), VSETSTATE, plotmd);
.PP
where
.I plotmd
is defined to be
.IP
\fBint\fR plotmd[] = { VPLOT, 0, 0 };
.PP
and
.I vp
is the result of a call to
.I fopen
on stdio.
When you finish using the Versatec in plot mode you should eject paper
by sending it a EOT after putting it back into print mode, i.e. by
.PP
'nf
	\fBint\fR prtmd[] = { VPRINT, 0, 0 };
	\&...
	fflush(vp);
	ioctl(fileno(vp), VSETSTATE, prtmd);
	write(fileno(vp), "\e04", 1);
.fi
.SH FILES
/dev/vp0
.SH SEE ALSO
vfont(5),
lpr(1),
lpd(8),
vtroff(1),
va(4)
.SH DIAGNOSTICS
The following error numbers are significant at the
time the device is opened.
.TP 10
[ENXIO]
The device is already in use.
.TP
[EIO]
The device is offline.
.SH BUGS
The configuration part of the driver assumes that the device is set up to
vector print mode through 0174 and plot mode through 0200.
As the configuration program can't be sure
which vector interrupted at boot time,
we specify that it has two interrupt vectors,
and if an interrupt comes through 0200 it is reset to 0174.
This is safe for devices with one or two vectors at these two addresses.
Other configurations with 2 vectors may require changes in the driver.