INT 15 - HUNTER 16 - ENABLE/TRAP EVENT

	AH = 6Eh
	AL = Software Interrupt
	      00h  do not trap event
	      else trap as software interrupt number AL
	BH = event number (see AH=6Dh)
	BL = enable mask
	    00h disable event
	    01h enable event
Return: AH = 00h if successful
SeeAlso: AH=6Dh,AH=6Fh