5 data holes (<-> bits), which makes 32 different values). Further reading Andrew D. Booth Technical Developments: The Development of A.P.E.(X).C. (in Automatic Computing Machinery), Mathematical Tables and Other Aids to Computation (MTAC) Volume 8, Number 46, April, 1954 References 1940s computers 1950s computers Computer-related introductions in 1948 Crystallography Early British computers One-of-a-kind computers