First computer program

In 1840, Babbage was invited to give a seminar at the University of Turin about his Analytical Engine. Luigi Menabrea, and the future Prime Minister of Italy, translated Babbage's lecture in French, and this transcript was then published in the Bibliothèque universelle de Genève in October 1842[1].

Ada Lovelace was the one who translated the lecture in English and added some notes, which were added to the translation. Lovelace spent almost a year doing this and was assisted with input from Babbage. Her notes, which are more extensive than Menabrea's paper, were then published in Taylor's Scientific Memoirs under the initialism AAL. In 1953 Lovelace's notes on Babbage's Analytical Engine were republished. With this the engine has now been recognised as an early model for a computer and her notes as a description of a computer and software.

Lovelace's notes were labelled alphabetically from A to G. In note G, she describes an algorithm for the Analytical Engine to compute Bernoulli numbers. It is considered the first algorithm for implementation on a computer, and Ada has often been cited as the first computer programmer for this reason.[2][3] The engine was never completed so her code was never tested.[4]

Lovelace's diagram from Note G, the first published computer algorithm

Conceptual leap

Ada Lovelace explained the difference between the Analytical Engine and previous calculating engines, particularly its ability to be programmed to solve problems of any complexity.[5] She realised the potential of the device extended far beyond mere number crunching. She wrote:

[The Analytical Engine] might act upon other things besides number, were objects found whose mutual fundamental relations could be expressed by those of the abstract science of operations, and which should be also susceptible of adaptations to the action of the operating notation and mechanism of the engine...[ 6]


[1]Robin Hammerman and Andrew L. Russell, eds. Ada's Legacy: Cultures of Computing from the Victorian to the Digital Age (Morgan & Claypool 2015)
[2]Simonite, Tom (24 March 2009). "Short Sharp Science: Celebrating Ada Lovelace: the 'world's first programmer'". New Scientist. Retrieved 14 April 2012.
[3]Parker, Matt (2014). Things to Make and Do in the Fourth Dimension. Farrar, Straus & Giroux. p. 261. ISBN 0374275653.
[4]Kim, Eugene Eric; Toole, Betty Alexandra (May 1999). "Ada and the first computer". Scientific American 280 (5): 71–76.
[5]Toole 1998, pp. 175–82.
[6]Hooper, Rowan (16 October 2012). "Ada Lovelace: My brain is more than merely mortal". New Scientist. Retrieved 16 October 2012.
[7]Wikipedia: The Free Encyclopedia. Wikimedia Foundation Inc. Updated 22 July 2004, 10:55 UTC. Encyclopedia on-line. Available from Species. Internet. Retrieved 10 August 2004.