Description
The IBM Type 31 Alphabetical Duplicating Punch, a motor-driven key punch from 1934, with a typewriter-like keyboard and a separate numeric keypad. This model (which was current with the release of the IBM 405 accounting machine, used the new (1928) standard 12x80 cards and was almost certainly in use at the statistical and astronomical laboratories, BASR, and elsewhere at Columbia prior to the introduction of the 024 and 026 models in 1949.
