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VP(4)                      Kernel Interfaces Manual                      VP(4)



NAME
       vp - Versatec printer-plotter

DESCRIPTION
       Vp0  is  the interface to a Versatec D1200A printer-plotter with a Ver-
       satec C-PDP11(DMA) controller.  Ordinarily  bytes  written  on  it  are
       interpreted  as  ASCII characters and printed.  As a printer, it writes
       64 lines of 132 characters each on 11 by 8.5 inch paper.  Only some  of
       the ASCII control characters are interpreted.

       NL     performs  the usual new-line function, i.e.  spaces up the paper
              and resets to the left margin.  It is ignored however  following
              a CR which ends a non-empty line.

       CR     is  ignored  if  the current line is empty but is otherwise like
              NL.

       FF     resets to the left margin and then to the top of the next page.

       EOT    resets to the left margin, advances 8 inches, and then  performs
              a FF.

       The  ioctl(2) system call may be used to change the mode of the device.
       Only the first word of the 3-word argument structure is used.  The bits
       mean:

       0400   Enter simultaneous print/plot mode.
       0200   Enter plot mode.
       0100   Enter print mode (default on open).
       040    Send remote terminate.
       020    Send remote form-feed.
       010    Send remote EOT.
       04     Send remote clear.
       02     Send remote reset.

       On  open  a  reset,  clear,  and form-feed are performed automatically.
       Notice that the mode bits are not encoded, so that it is required  that
       exactly one be set.

       In plot mode each byte is interpreted as 8 bits of which the high-order
       is plotted to the left; a `1' leaves a visible dot.   A  full  line  of
       dots is produced by 264 bytes; lines are terminated only by count or by
       a remote terminate function.  There are 200 dots per inch  both  verti-
       cally and horizontally.

       When  simultaneous print-plot mode is entered exactly one line of char-
       acters, terminated by NL, CR, or the remote terminate function,  should
       be  written.  Then the device enters plot mode and at least 20 lines of
       plotting bytes should be sent.  As the line of characters (which is  20
       dots  high)  is  printed,  the  plotting  bytes overlay the characters.
       Notice that it is impossible to print characters on baselines that dif-
       fer by fewer than 20 dot-lines.

       In  print mode lines may be terminated either with an appropriate ASCII
       character or by using the remote terminate function.

FILES
       /dev/vp0

SEE ALSO
       opr(1)



                                                                         VP(4)