This paper describes a problem and one solution to the problem which arose during the logical design of a digital computer for the real-time simulation of airplane flight. The computer in question is a 1-address machine with magnetic core memory which performs the basic operations of addition, comparison, transfer from arithmetic unit to memory, etc., at the rate of one operation every 5 microseconds. The logic of the machine is realized in pulse-type diode switching circuits similar to those employed by the National Bureau of Standards Eastern Automatic Computer and operating at an allowable pulse repetition frequency of 1.2 megacycles.