Draft:40-bit computing

In computer architecture, 40-bit integers, memory addresses, or other data units are those that are 40 bits (5 octets) wide. Also, 40-bit central processing unit (CPU) and arithmetic logic unit (ALU) architectures are those that are based on registers, address buses, or data buses of that size.

List of 40-bit computer systems

^ Baker, C., Chan, D., Cherry, J., Corry, A., Efland, G., Edwards, B., Matson, M., Minsky, H., Nestler, E., Reti, K., Sarrazin, D., Sommer, C., Tan, D., & Weste, N. (1987). Symbolics ivory processor: a 40 bit tagged architecture lisp microprocessor. In 1987 IEEE International Conference on Computer Design, VLSI in computers & processors : ICCD '87, Rye Town Hilton, Rye Brook, N.Y. (pp. 512-515). Institute of Electrical and Electronics Engineers (IEEE).

Computer architecture bit widths
Bit
1 2 4 8 12 16 18 24 26 28 30 31 32 36 40 45 48 60 64 128 256 512 bit slicing
Application
8 16 32 64
Binary floating-point precision
16 (×½) 24 32 (×1) 40 64 (×2) 80 128 (×4) 256 (×8)
Decimal floating-point precision
32 64 128