INT 7C - SK-UPPS Data Link Interface 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. - TRANSMIT FRAME RELEASE
	AX = 0013h
	ES:BX -> Mbuf (see #03847)
Return: nothing
Notes:	Returns immediately; The protocol's Transmit Upcall will NOT be called.
	The Mbuf may no more be used by the protocol in any way (i.e. the
	  Mbuf's IN USE field may not be polled).
SeeAlso: AX=0004h,AX=0013h