INT 16 U - TextWare TWTSR - 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.
	AX = 3577h
	CX = function
	    00CBh ???
		Return: AX = 0000h
			BX = 0000h
			DX:CX -> ???
	    00CCh uninstall
		Return: AX = status
			    0000h successful
			    FFFDh unable to unload because vectors taken
	    00CDh ???
		Return: AX = 0000h
			BX = 0000h
			DX:CX -> ???
	    other
		Return: AX = 5345h ('SE')
Program: TWTSR is a TSR(Terminate and Stay Resident) A program which remains in memory after terminating in order to provide services to other programs or the user.  The name comes from the name of the DOS function call used to remain in memory after termination. which allows the TextWare hypertext browser to be
	  popped up via hotkey
SeeAlso: AX=D724h