Stibitz originally studied the magneto-mechanic of telephone rays, but turned his attention to the binary circuits controlled by the relays, to the arithmetic operations expressible in binary form, and, in November 1937, to the construction of a two-digit binary adder. The next year, with the help of S.B. Williams of Bell Labs, he developed a full-scale calculator for complex arithmetic. This computer was operational late in 1939 and was demonstrated in 1940 by remote control between Hanover, New Hampshire, and New York. Several binary computers of greater sophistication followed. In these were introduced the excess 3 code, floating decimal arithmetic, self-checking circuits, jump program instructions, taped programs and 'table-hunting' subcomputers.
Born in York, Pennsylvania, Stibitz attended Moraine Park, an experimental school in Dayton, Ohio, and graduated from Denison University in 1926 with a Ph.D. in Applied Mathematics. He received an M.S. from Union College in 1927 and a Ph.D. in physics from Cornell in 1930. Stibitz joined Bell Telephone Laboratories in 1930 and served as a mathematical consultant. From 1940 to 1945 he was on loan to the U.S. Office of Scientific Research and Development. Following World War II, he was an independent consultant in applied mathematics for various government and industrial agencies. In 1964 he joined the Department of Physiology at Dartmouth Medical School as a research associate. He then worked primarily on applications of physics, mathematics, and computers to biophysical systems. He became a professor in 1966 and professor emeritus in 1970.