These constants are used by Turbo Pascal's file-handling procedures
   when files are opened or closed.  The mode fields of the file
   variables will contain one of the following values:

                         FmClosed   = $D7B0;
                         FmInput    = $D7B1;
                         FmOutput   = $D7B2;
                         FmInOut    = $D7B3;