INT 2F - RTS Control 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. - INSTALLATION CHECK AX = FEEFh Return: AX = EFFEh if installed BX = port address Program: RTS Control 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. is a utility by Michal Szokolo to lower the RTS signal on a COM port during disk accesses to avoid losing incoming data