A few notes about the program. First, I should note that it has evolved over nearly 20 years, 
so there are portions which are no longer used and other portions which should be rewritten 
in a more logical manner! (but that's the way code such as this always is).

Menu:
  File : allows you to enter input file name
  Orbital elements : options are as follows:
      YES: input file always includes orbital elements as second line, 
      NO: input file just includes ID line and individual measures, or 
      MAYBE: second line of input file will indicate whether it includes elements
  P,a : option to type in period and semi-major axis for inclusion as text within plot
  Pub1, Pub2, Pub3 : option to include input files for up to three other orbits. These are 
      simple text files containing a string of theta and rho values. The orbits are plotted 
      as dotted ellipses. Useful mainly to indicate how a new orbit differs from previously 
      published ones. I've included a sample file, as well as the simple fortran program 
      puborb.f which was used to generate it.
  Plot nodes : option whether or not to plot the line of nodes (as dot-dash line)
  Plot O-C : option whether or not to plot lines connecting measures to their predicted 
      locations along orbit
  Zoom factor : allows you to zoom in on portion of orbit. Enter zoom factor, then click on 
      portion of orbit you wish to center on
  RVplot : plots predicted radial velocity curves based on this visual orbit. It has been 
      many years since I last used this, so I would have to investigate what assumptions are 
      made for this!
  Rayleigh limits : allows you to plot Rayleigh limits for up to two different telescope 
      apertures. Useful for close orbits which are not always resolvable. The program always
      asks for two values, so if you want only one just enter the same value twice (not very
      clever, but it works...)
  Header type : allows a different format for ID line of input file (probably best to ignore 
      this and always use default format)
  Multiple plots : option for input file containing more than one ID+orbit+measures. Handy 
      for my catalog work, as I may generate hundreds of orbits at once
  Write PS file : option to write postscript version of plot
  Write PNG file : option to write PNG version of plot

  REPLOT : replots same pair (after, for example, changing one of the abovementioned options)
  PLOT NEXT : plot next star (when using multiple-star input)
  Batch mode : option to process all stars of multiple-star input file, generating PS or PNG 
        files for all of them

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Input file:
- first line is just part of the WDS summary line. The program reads the WDS designation 
  (col 1-10) and the binary name and components (col 11-22)
- second line is usually just a YES or NO, telling the program whether there are orbital 
  elements to read. As described above, there are also options in the program to always read 
  orbital elements (in which case this line is deleted) or never read elements (in which case 
  this and the following line are deleted)
- orbital elements (P, a, i, Omega, T, e, omega) and reference for orbit. The units for P 
  (y=years, d=days, c=centuries), a (a=arcsec, m=mas), and T (y=years, d=days) follow those 
  elements. For T in days, it assumes you're using MJD
- individual measures. Each line includes date (Besselian year), theta (degrees), rho (arcsec), 
  a code for measurement technique, weight given to observation, and other miscellaneous codes 
  from the WDS. The only portion of this miscellaneous information which is used by the 
  program is columns 66-68, the 3-letter code for the reference.

  The measurement techniques are as follows:
    VIS = visual micrometry (plotted as green plus sign)
    VPH = photography (purple asterisk)
    CSP = CHARA speckle (filled blue circle)
    XSP = other speckle or related technique  (filled blue circle). If the reference is NOI 
          (for NPOI) or MkT (for the Mark III interferometer), it's long-baseline interferometry, 
          so plotted as a filled square. An obvious add-on here, which should be rewritten to
          have a separate technique code for long-baseline data
    XVI = eyepiece interferometry (open blue circle)
    WSI = USNO speckle (filled blue star)
    HIP = Hipparcos (red "H")
    TYC = Tycho (red "T")

  The weight was used at one point to scale sizes of the individual measures, but no longer. 
  It's only use now is to indicate whether the O-C line connecting the measure to its predicted 
  location along the orbit is a solid line (non-zero weight) or dotted line (zero weight)

There is an option for multiple plots. For this option, there is a blank line following the 
final measure for each pair.

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Sample files:
  wds11182+3132.plt - input file, including orbit and published measures for xi UMa
  wds11182+3132.Sav1830 - published orbit for xi UMa (I think the earliest one, published in 
        1830 by Savary.