The problem of computing the optimum control function for a pulse frequency modulated system using a technique based on the modified maximum principle (MMP) is presented. The MMP requires that a certain function denoted by

be extremized in the process of obtaining the optimum control function. By assuming a specific form for the performance index and in the definition of the state variables, a form for

was achieved which is much more amenable to computation. A brief description of a computer program, for maximizing

and thus obtaining the optimum control function, is included.