INT 62 u - FGDRIVER v4.02 - "FG_GETVPAGE" - GET VISIBLE VIDEO PAGE NUMBER
	AX = 0050h
Return: AX = visible video page (0000h-003Fh)
Note:	the FGDRIVER functions are rearranged with each major release, but
	  their parameters do not change (see #03474 at AX=0000h)
SeeAlso: AX=0043h,AX=004Ch,AX=00B6h