Syntax: spim1 (FITS file) [2nd FITS file] [id=file] [ssf=v]
                 [-vt100]  [row=v]  [-desat]  [-verbose]
  Spectra-in-an-image interactive plotting program.
  This program is used for interactive wavelength calibrations.
     "ssf=v"   : is the strength scale factor (default is 1.0)
                   to apply to the second image only.
     "row=v"   : starts by plotting row v.
     "-vt100"  : for plotting on a VT100 with Retrographics.
     "-desat"  : to correct for saturated and bleeding columns.
     "-verbose": no verbosity.