The DES-1: a real-time digital simulation computer

Abstract

Historically, there have been two lines of development in the attempt to apply digital techniques to the solution of those types of differential equations that have traditionally been solved by analog methods. The first started at Northrup Aircraft in approximately 1948 and led to the development of the digital differential analyzer. The original digital differential analyzers were slow but, in context of the state of digital technology at the time, provided a computing method not otherwise available; in 1948, high-speed internally-programmed general purpose computers were not in general use. As digital techniques developed, digital differential analyzers were increased in speed and in complexity. The most recent of these, the TRICE, is a very high-speed parallel digital differential analyzer that operates at approximately ten thousand times the speed of early digital differential analyzers. The second line of development was started at the Moore School in the investigation of general purpose digital techniques for operational flight trainers. This line of development has been carried on into the present at M.I.T. The emphasis has been on stability considerations and algorithms which would permit computers with a given speed to simulate high performance aircraft.