This paper describes a real-time digital computer program that controls the application of electrical power to the S-IVB stage of the Saturn vehicle at Cape Kennedy, Florida. Douglas Aircraft Company, the S-IVB stage manufacturer, provided NASA with the program requirements relative to the energizing sequence, voltage and current measurement tolerances, and vehicle system operational tests. International Business Machines Corporation provided NASA with the computer program to satisfy the task requirements. The program conjoined the components of the Electrical Support Equipment (two RCA 110A computers and control and instrumentation devices) into a closed loop system. The supporting operating system program by IBM is described.