__NOTOC__ The British Tabulating Machine Company (BTM) was a firm which manufactured and sold Hollerith unit record equipment and other data-processing equipment. During

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

, BTM constructed some 200 " bombes", machines used at

Bletchley Park Bletchley Park is an English country house and estate in Bletchley, Milton Keynes (Buckinghamshire) that became the principal centre of Allied code-breaking during the Second World War. The mansion was constructed during the years following ...

to break the German Enigma machine ciphers. The company was formed in 1902 as The Tabulator Limited, after Robert Porter obtained the rights to sell Herman Hollerith's patented machines from the US Tabulating Machine Company (later to become IBM). By 1909, the company had been renamed the "British Tabulating Machine Company Limited". In 1920, the company moved from London to Letchworth, Hertfordshire; it was also at this point that it started manufacturing its own machines, rather than simply reselling Hollerith equipment. Annual revenues were £6K in 1915, £122K in 1925, and £170K in 1937. In 1916 there were 45 staff; this increased to 132 in 1922, 326 in 1929 and 1,225 in 1939. In return for the exclusive right to market Hollerith equipment in Britain and the Empire (excluding Canada), BTM paid 25% of its revenues to the American company by way of royalties. This became an ever-increasing burden as the years progressed; BTM attempted to renegotiate the agreement on several occasions, but it was only finally terminated in 1948. During World War II, BTM was called upon to design and manufacture a machine to assist breaking the German Enigma machine ciphers. This machine, known as a bombe, was initially conceived by

Alan Turing Alan Mathison Turing (; 23 June 1912 – 7 June 1954) was an English mathematician, computer scientist, logician, cryptanalyst, philosopher, and theoretical biologist. Turing was highly influential in the development of theoretical c ...

, but the actual machine was designed by BTM chief engineer

Harold 'Doc' Keen Harold Hall "Doc" Keen (1894–1973) was a British engineer who produced the engineering design, and oversaw the construction of, the British bombe, a codebreaking machine used in World War II to read German messages sent using the Enigma machin ...

, who had led the company's engineering department throughout the 1930s. The project was codenamed "CANTAB". The project was managed by computing pioneer Dora Metcalf until 1942. By the end of the European war, over two hundred bombes had been built and installed.

HEC computer

BTM built a valve based computer called the HEC (Hollerith Electronic Computer). The first model (HEC 1) was built in 1951, an example is held by the Birmingham Museum. BTM went on to develop the HEC 2, 2M and 4 models, eventually building more than 100. The machines had a 2 kilobyte drum memory and 1000 valves, and could use punched cards for input and output, or drive a printer.

Merger

In 1959 BTM merged with former rival Powers-Samas to become International Computers and Tabulators Limited (ICT). ICT later became part of ICL (

International Computers Limited International Computers Limited (ICL) was a British computer hardware, computer software and computer services company that operated from 1968 until 2002. It was formed through a merger of International Computers and Tabulators (ICT), English ...

), which was later taken over by

Fujitsu is a Japanese multinational information and communications technology equipment and services corporation, established in 1935 and headquartered in Tokyo. Fujitsu is the world's sixth-largest IT services provider by annual revenue, and the la ...

References

* John Harper, BTM – British Tabulating Machine Company Limite

* John Keen, Harold 'Doc' Keen and the Bletchley Park Bombe, 2003, . * Martin Campbell-Kelly, ICL and the British computer industry

*

External links

Letchworth's Enigma

Grace's Guide to British Industrial History – British Tabulating Machine Co

The BTM HEC Paperwork Collection at The ICL Computer Museum
{{Authority control Defunct manufacturing companies of the United Kingdom International Computers Limited Cryptanalytic devices Manufacturing companies established in 1902 1902 establishments in England British companies established in 1902 British companies disestablished in 1959 1959 disestablishments in England