vp(4)				  Unsupported				 vp(4)

Name
       vp - Versatec interface

Syntax
       device vp0 at uba0 csr 0177510 vector vpintr vpintr

Description
       The Versatec printer/plotter is normally used with the programs or This
       description is designed for  those  who	wish  to  drive	 the  Versatec
       directly.

       To use the Versatec yourself, you must realize that you cannot open the
       device, if there is a daemon active.  You can see if there is a	daemon
       active by doing a and seeing if there are any files being sent.

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

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

       where plotmd is defined to be

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

       and is the result of a call to 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

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

       N.B.: If you use the standard I/O library with the Versatec you must do

	      setbuf(vp, vpbuf);

       where is declared

	      char vpbuf[BUFSIZ];

       otherwise the standard I/O library, thinking that  the  Versatec	 is  a
       terminal	 (since	 it  is	 a character special file) will not adequately
       buffer the data you are sending to the Versatec.	 This will cause it to
       run extremely slowly and tends to grind the system to a halt.

Restrictions
       The  configuration  part of the driver assumes that the device is setup
       to vector print mode through 0174 and plot mode	through	 0200.	 Since
       the  driver  doesn't care whether the device considers the interrupt to
       be a print or a plot interrupt, it would be preferable to have these be
       the  same.   This since the configuration program can't be sure at boot
       time which vector interrupted and where the interrupt vectors  actually
       are.   For  the time being, since our versatec is vectored as described
       above, we specify that it has two interrupt vectors and are careful  to
       detect  an  interrupt  through 0200 at boot time and (manually) pretend
       the interrupt came through 0174.

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.

Files
See Also
       vfont(5), lpr(1), lpd(8), vtroff(1), va(4)

				      VAX				 vp(4)

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