An audio plug adapter has a sleeve, an audio plug assembly rotatable coupled to the sleeve, a female connector received in the sleeve and a cable interconnected between the audio plug assembly and the female connector. The TDMA mobile terminal has a display and includes a controller for subtracting time slots necessary for a call from an overall number of time slots corresponding to a TDMA frame to obtain remaining time slots. The first mode channel includes a voltage mode driver and a current mode driver for outputting the differential transmission signal.