The early use of special purpose analog computers in flight trainers faced many problems. These difficulties along with the recognition that the then emerging digital computer technology might be applied to training systems led to investigations of this area. The purpose of this paper is to trace the research and development of high-speed digital computers for real-time operations in solving the flight equations in real time through the current state-of-the-art digital systems used in flight trainers. Three basic aspects of real-time digital computer systems for flight trainers are reviewed; namely, computer system architecture, iteration rates required, and programming. In addition, a forecast of future systems architecture and programming concepts based on research currently underway is offered.