Call with HPLP [options]
   Options:
        -Ixx: where xx is the hex interrupt vector.
              Default 0x7b.

        -Cx:  where x is the serial port 1 or 2.
              COM1 is the default.

        -Ffilename: plot TO a file, where filename is the file name.
              Default is plot directly to plotter.

        -P: No PageAdvance after plot.
              Default is to send a form feed after every plot.

        -W: Turn on WAIT option.                
              Default is no wait (see HPLP.DOC). 

        -N  Turn off clip limit and device presence checking.

        -M  Change the default units from INCHES to MILLIMETERS.

         D  The drive to be used to store temp files during LongPlots.
              (Where D is the drive name) Default is the current directory.

        -?: or -H: Prints this message
