Programming a Duplex Computer System This paper describes a method of duplex-computer programming that has been used with two computers in a military defense system. The method combines special programs with a basic data processing program package. The duplex operation gives the system greater reliability. After achieving the required level of integration, both computers do similar processing on the same inputs and continually cross-check the intermediate and final results. CACM November, 1961 Dow, J. CA611116 JB March 15, 1978 10:40 PM 252 5 252 252 5 252 252 5 252