A freely available real-time operating system well suited for astronomy and the physical sciences

This paper wants to be a practical example in building a real-time data-acquisition and control system from scratch using relatively non-expensive PC hardware and open-source software. The practical example of building the control system for the Michigan Infrared Combiner (MIRC) at the CHARA interferometer will be used to give the reader a 'hands-on' experience in installing and configuring the RTAI-Fusion real-time operating system and developing a complete control system with it.