15.64.18.9  HPGL   - This  is  for a generic Hewlett Packard plotter.  The
plotter pauses in between each plot to wait for a new sheet of paper.  The
colors you select are mapped to pen numbers as:
     1.  WHITE
     2.  Red
     3.  Green
     4.  Blue
     5.  Yellow
     6.  Magenta
     7.  Cyan
Options are:

     1.  WIDTH=n.n - Paper width in cm (Default:26.0) 
     2.  HEIGHT=n.n - Paper height in cm (Default:20.0)
     3.  XSCREEN=n.n - X Offset of plot in cm (Default:0.0)
     4.  YSCREEN=n.n - Y Offset of plot in cm (Default:0.0)
     5.  UNITS=nn.n - Number of pixels/cm (Default:400)
     6.  MAXCOLOR=n  -  Maximum number of pens (Default:7) This may be set
         within the range of 1 to 7.  All pens requested larger than  this
         value will revert to to the maximum.
     7.  PENLIST=n1n2n3n4n5  -  maps  penwidths to .01 cm.  from 01 to 99.
         (Default:PENLIST=0103050709) 01 is the minimum pen width.
     8.  GENIL simulate intensity levels by doing multiple passes with the
         pen.  If not specified then the PENLIST is ignored.
     9.  PENWIDTH=n.n - The width of the pen points in cm (Default:0.03)
If you wish to default to HP plotter output:
     $ DEFINE PLOT_TERM "UGHPGLD[,options]"

These  options may work differently depending on the plotter.  Most of the
big plotters have the origin at the center of tha page,  while  the  small
ones   use   an   origin   at   a   corner.   By  suitably  adjusting  the
WIDTH,HEIGHT,XSCREEN,YSCREEN any coordinate system or  page  size  may  be
accomadated.  MAXCOLOR=1 is useful when you wish to reduce a color plot to
a single color.

                                  example
     TD:SET DEVICE HPGL "PENLIST=0309152430"
Sets up to draw with much wider lines.