R_IsSVGA() 
 Determines if a SuperVGA adapter is available
------------------------------------------------------------------------------

 Syntax
        lIsSVGA := R_IsSVGA ()

 Parameters
        (None)

 Returns
        lIsSVGA         .T. :   PC has a, by RPCXLib supported, SuperVGA
                                adapter
                        .F. :   PC doesn't have a supported SuperVGA adapter

 Description
        This function determines if the PC has a SuperVGA adapter which
        is supported by RPCXLib.

 Example
        IF R_IsSVGA ()
                R_ShowPCX ( 'SUPERPIC.PCX' )
                [...]
        ELSE
                IF R_IsVGA ()
                        R_ShowPCX ( 'STANDVGA.PCX' )
                        [...]
                ELSEIF R_IsEGA ()
                        R_ShowPCX ( 'STANDEGA.PCX' )
                        [...]
                ELSE
                        Alert ( 'Minimum requirement is an EGA adapter !' )

                ENDIF
        ENDIF

 Remark
        This function is a pseudo function and is declared in RPCXLib.CH.