IBM 405 Alphabetical Accounting Machine introduced

IBM 405 Alphabetical Accounting Machine introduced

The IBM 405 Alphabetical Accounting Machine, 1934. This was IBM's high-end tabulator offering (and the first one to be called an Accounting Machine), complementing its numeric-only 285.

The 405 was programmed by a removeable plugboard with over 1600 functionally significant "hubs", with access to up to 16 accumulators, the machine could tabulate at a rate of 150 cards per minute, or tabulate and print at 80 cpm. The print unit contained 88 type bars, the leftmost 43 for alphanumeric characters and the other 45 for digits only. The 405 was IBM's flagship product until after World War II (in which the 405 was used not only as a tabulator but also as the I/O device for top-secret relay calculators built by IBM for the US Army Signal Corps in 1943, used for decrypting German and Japanese coded messages ). In 1952, IBM first used core memory in an experimental 405 model.





IBM 405 Alphabetical Accounting Machine introduced

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