INT 14 - DimVGA v2.0+ - DIM SCREEN 'MANUALLY'                                   
	AX = AA08h
Return: AX = FFFFh
Note:	this function will dim the screen immediately, even if DimVGA is
	  currently disabled
SeeAlso: AX=AA01h,AX=AA02h,AX=AA09h
Index:	screen saver;DimVGA