HERC.BGI - Supplemental Documentation

  HERC.BGI is a "unified" driver that support both the Hercules 
  monochrome graphics cards (in 2 colors) and Hercules InColor Card
  (in 16 colors).  This B.G.I. driver is appropriate for use with
  Turbo C 2.0 and Turbo Pascal 5.0.

  Since the present BGI kernal does not recognize a InColor card 
  when it tries to autodetect the attached video card in the system,
  this HERC.BGI has built the DETECT function built into the driver
  itself.  If an InColor card is present in the system, the driver will
  detect it during its installation and act accorrdingly - that is,
  operate in 16 colors.

  The InColor card will share the same GraphDriver and GraphMode
  values with the monochrome graphics cards.  That is, 
  GraphDriver = HERCMONO, and GraphMode = HERCMONOHI.

  To autodetect an InColor card, the following sequence of code
  could be used: (in C syntax)

  graphdriver = DETECT;
  initgraph(&graphdriver, &graphmode, "");
     /* ...
       graphics error processing 
     */
  if (graphdriver == HERCMONO) {
     if (getmaxcolor() == 15) {
       ... /* InColor card */
     }
  else {
       ... /* monochrome graphics cards */
     }
  }
  ....

NOTE - The Autodetect function of Borland's BGI will always want to load the
       driver of the device that it identifies as the highest performance
       adapter in the system.  This means that in some dual monitor
       configurations the DETECT function may force the BGI driver to
       what it identifies as the higher performance graphics mode.  For
       example, in systems that include both a Hercules InColor Card and a
       Hercules VGA Card, the BGI Autodetect function will load the EGAVGA.BGI
       driver even though you may want to execute the program on the InColor
       Card.  In such a case, you must explicitly name the HERCMONO as the
       graphdriver rather than use the DETECT function.