INT F1 - Common ISDN API(Application Program[ming] Interface) The defined set of calls which a program may make to interact with or request services of the operating system or environment under which it is running.  Because the inputs and outputs of the calls are well-defined, a program using the API can continue using the identical calls even if the internal organization of the program providing the API changes. (CAPI) v2.0 - "CAPI_GET_MESSAGE"
	AL = 04h
	AH = CAPI version number * 10 (14h for v2.0)
	DX = application ID (see AH=01h)
Return: AX = status (0000h,11xxh) (see #04070)
	ES:BX -> message if successful (see #04071)
Range:	INT 00 to INT FF, selectable by program parameter
Notes:	the caller is required to provide at least 512 bytes of stack space
	the returned message may be overwritten by the next call to this
	  function
SeeAlso: AH=04h,INT F1/AL=03h