ISHERCULES()
 Determines if a HERCULES card is present or can be emulated
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 Syntax

     ISHERCULES([<lMode>]) --> lHERCULES

     Important!  Contains <lMode>, an additional optional parameter over
     and above the original CA-Clipper Tools.

 Argument

     <lMode>  When designated as .T., determines if a HERCULES card is
     present.  The default value .F. tests to see if a Herculess adapter can
     be emulated.

 Returns

     In conjunction with the <lMode> parameter, ISHERCULES() returns a .T.
     when a HERCULES card is present or a HERCULES adapter can be emulated.

 Description

     This function determines two things.  When <lMode>  is designated as
     .F., or the function is called without parameter, ISHERCULES()
     determines if a HERCULES adapter can be emulated.  This could be the
     case with a VGA or EGA card.  When <lMode> is .T., it determines if
     there is a HERCULES card present.

 Notes

     .  GETMODE() determines the active mode.

     Warning!  Although our function implies it, not all EGA and VGA
     cards can emulate HERCULES.  In most cases, a HERCULES emulation on a
     VGA card is possible , but it cannot be determined with absolute
     certainty.  As long as the text is output under CA-Clipper, working with
     ISMONO() should be sufficient

 Example

     Can HERCULES be emulated?

     If ISHERCULES()
        * ...
     ENDIF
     HERCULES card?
     IF ISHERCULES(.T.)
        * ...
     ENDIF