Cycle- and delay-time considerations in a real-time digital computer

The use of digital computers in physical control systems requires consideration of certain special effects not normally encountered with analog computers, namely, the sampling action and the computation delay. In this paper, the two effects are defined and their relationship to the digital computer program established. It is shown how they may be selected so as to result in program optimization. A special “information-handling efficiency” criterion is developed to provide a basis for defining program quality. A general discussion is given of methods for improving the program quality by taking into account the variations in information contents among the input-output data paths in a program.