Columbia University Computing History

## IBM Calculators

In the first half of the 20th Century, IBM's flagship product was the Tabulator, which is pretty much just a big adding machine. Beginning about 1930, IBM began to produce machines that could also multiply, and eventually divide, as well as add and subtract. These were called Calculators and they were used primarily for engineering and scientific applications. They differ from desktop calculators in taking their input from decks of cards rather than a keyboard, and in punching their results on cards, rather than displaying them on a counter or printing them on a slip of paper, and by having some programming capability; thus they are automatic rather than manual. They differ from accounting machines not only in having more arithmetic functions, but also in lacking any printing or report-generation capability. They could, however, be linked to accounting machines as an auxilliary arithmetic unit.

Here is a table of IBM's automatic calculators; click on the links to visit pages about specific models:

IBM Calculators
Type Name Introduced Repertoire Remarks
601 Multiplying Punch 1931  + - ×  (mechanical) First IBM calculator that could multiply.
Aberdeen Pluggable Sequence Relay Calculator 1944  + - × ÷ √  (relays) Advanced machine for WWII work.
602 Calculating Punch 1946  + - × ÷  (mechanical) First commercial IBM calculator that could divide.
602-A Calculating Punch 1948  + - × ÷  "A 602 that worked".
603 Electronic Multiplier 1946      ×  The first electronic calculator (vacuum tubes).
604 Electronic Calculating Punch 1946  + - × ÷  Hundreds times faster than the 601-602.
605 Electronic Calculator 1949  + - × ÷  (vacuum tubes) The "CPU" of the Card-Programmed Calculator.
607 Electronic Calculating Punch 1953  + - × ÷  Like a 605 with more memory (there was no 606).
608 Calculator 1953  + - × ÷  The first all-solid-state computing machine.
609 Calculator 1960  + - × ÷  A faster 608 with more memory.
610 Auto-Point Computer 1957  + − × ÷ √  True floating point; interactive, programmable, the first "personal computer".

The 610 is listed because IBM placed it next in line in its 600 series, but in fact it is quite a different species. Unlike the others, it is a standalone self-contained computer. Rather than cards for I/O, it has a keyboard, a CRT, and a printing typewriter, plus paper tape.

The demand for greater flexibility and capacity during the decade from 1946 to 1956 brought forth the Card Programmed Calculator (a 604 or 605 combined with a tabulator, card punch, and memory) and then true stored-program computers such as the SSEC, NORC, 650, and 701, which IBM still called "calculators", perhaps so as not to cause the many human computers to fear for their jobs. In the mid-1950s, the preferred term became "data processing system".

Also See:
Tabulators, Sorters, Key Punches, Collators, Reproducers, Interpreters.

 Columbia University Computing History Frank da Cruz / fdc@columbia.edu This page created: January 2001 Last update: 27 March 2021