R_VGACard()
 Determines which SuperVGA adapter is present
------------------------------------------------------------------------------

 Syntax
        nSVGACard := R_VGACard ()

 Parameters
        (None)

 Returns
        nSVGACard       Code of the detected SuperVGA adapter.
                        These codes are defined in RPCXLib.CH.

 Description
        This function tries to determine which SuperVGA adapter is
        available in the PC.

 Example
        && Determines the SuperVGA adapter

        *-- RPCXLib definitions
        #include "RPCXLib.CH"

        *-- Code of SuperVGA adapter
        LOCAL   nSVGACard

        *-- Array with the names of the known SuperVGA adapters
        LOCAL   aSVGANames := PL_SVGA_NAMES

        nSVGACard := R_VGACard ()
        ? 'SuperVGA in this PC : ', aSVGANames [nSVGACard]