Abstract: A portable data processor such as a personal digital assistant (PDA) which is designed to perform a data processing function and a mobile communication function is provided. The data processor has a touch sensitive display for data entry and display installed in a top surface of a body and a microphone and a speaker installed in a back surface of the body. These arrangements allow a user to take up the PDA without passing it from one hand to the other hand when a telephone call is received on a desk, for example.