The Laddic — A magnetic device for performing logic

The Laddic is a ladder-like structure cut out of a rectangular hysteresisloop ferrite. The sides of the ladder and all of the rungs are equal in minimum cross section so that all possible paths are flux-limited. The structure presents a large number of possible flux paths. By controlling the actual switching path through the structure any Boolean function of n variables ran be produced. A number of methods of operation are discussed, and design formulae and experimental results presented. One of the attractive features of this device is that the operating currents are not critical. Therefore, it can be operated at speeds limited essentially only by the current drives available. The output may be taken during the input variable phase or during a subsequent reset phase. Switching speeds of a few tenths of a microsecond and repetition rates of a few hundred kilocycles hare been achieved.