Skip Techniques for High-Speed Carry-Propagation in Binary Arithmetic Units

After a very brief summary of the various well-known methods of expediting carry-propagation in binary arithmetic units, the paper discusses and develops the ``anticipated-carry'' or ``carry-skip'' technique originally due in decimal form to Babbage, much used in mechanical calculators and lately revived for use in binary units. Various degrees of refinement are possible. It appears that for a given expenditure, the technique results in a unit which is simpler and faster than those using one of the other techniques. Conversely in order to attain a given speed with given circuit elements, the skip technique appears to minimize the equipment requirement among the known speed-up techniques.