A number a was placed in the memory register manually to serve as the multiplicand and similarly, numbers b, c were placed in the Arithmetic register and the accumulator register… so chosen that at the end of the operation b, c were again in the Arithmetic and accumulator registers, and a was left in the memory register. Thus the operation is periodic, and… the neons associated with the toggles of the registers appear to the human eye to be stationarily on.

[Jack Rosenberg to Julian Bigelow]