The files

       GRAPH.PAS      PLOT.MOD     and    F.PAS

  form a graphing procedure.  GRAPH is the driving procedure for
  the procedure PLOT,  GRAPH  chats with the user at the console
  while plot does all the work.   F  supplies the function to be
  plotted.

  The procedure PLOT uses escape-codes valid for an IMSAI VIO board,
  hence is not likely to work on any other machine without change.
  The form of the procedure is modular and I hope well commented, it
  should be easilly modified for other machines.