INT 62 u - FGDRIVER v4.02 - "FG_GETYJOY" - GET VERTICAL POSITION OF JOYSTICK
	AX = 0056h
	BX = joystick number (0001h or 0002h)
Return: AX = vertical position of joystick
	    FFFFh if joystick uninitialized or not present
Notes:	the FGDRIVER functions are rearranged with each major release, but
	  their parameters do not change (see #03474 at AX=0000h)
	The actual coordinates are processor- and joystick-dependent
	You must call "FG_INITJOY" (AX=005Eh) before using this function
SeeAlso: AX=0009h,AX=0052h,AX=005Eh,AX=0062h,AX=0077h