VP(4)                  OpenBSD Programmer's Manual (VAX)                 VP(4)

NAME
     vp - Versatec interface

SYNOPSIS
     device vp0 at uba0 csr 0177510 vector vpintr vpintr

DESCRIPTION
     The Versatec printer/plotter is normally used with the line printer sys-
     tem.  This description is designed for those who wish to drive the Ver-
     satec directly.

     To use the Versatec yourself, you must realize that you cannot open the
     device, /dev/vp0 if there is a daemon active.  You can see if there is a
     daemon active by doing a lpq(1), and seeing if there are any files being
     sent.  Printing should be turned off using lpc(8).

     To set the Versatec into plot mode you should include <sys/vcmd.h> and
     use the ioctl(2) call

           ioctl(fileno(vp), VSETSTATE, plotmd);

     where plotmd is defined to be

           int plotmd[] = { VPLOT, 0, 0 };

     and vp is the result of a call to fopen on stdio.  When you finish using
     the Versatec in plot mode you should eject paper by sending it a EOT af-
     ter putting it back into print mode, i.e. by

           int prtmd[] = { VPRINT, 0, 0 };
           ...
           fflush(vp);
           ioctl(fileno(vp), VSETSTATE, prtmd);
           write(fileno(vp), "\04", 1);

FILES
     /dev/vp0

DIAGNOSTICS
     The following error numbers are significant at the time the device is
     opened.

     [ENXIO]  The device is already in use.

     [EIO]    The device is offline.

SEE ALSO
     lpr(1), vtroff(1), va(4), font(5), lpd(8)

HISTORY
     A vp driver appeared in Version 7 AT&T UNIX.

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 con-
     figuration 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.

OpenBSD 2.9                     March 27, 1991                               1
