Ada Byron's notes on the analytical engine
Augusta Ada King, Countess of Lovelace (born Ada Byron) is renowned for her description and associated notes on Charles Babbage's design for a mechanical computer called The Analytical Engine. The analytical engine was never built, but Ada's notes are widely recognized as containing the first ever computer program.
History
In 1842 Charles Babbage was invited to give a seminar at the University of Turin about his analytical engine. Luigi Menabrea, a young Italian engineer, and future prime minister, wrote up Babbage's lecture in French, and this transcript was subsequently published in the Bibliothèque Universelle de Genève in October 1842.
Babbage asked Ada Lovelace (born Ada Byron), to translate Menabrea's paper into English, subsequently requesting that she augment the notes she had added to the translation. Ada spent most of a year doing this. These notes, which are more extensive than Menabrea's paper, were then published in The Ladies Diary and Taylor's Scientific Memoirs under the initialism "A.A.L.".
Content
Her notes were labeled alphabetically from A to G. Note G is the longest of the seven. In note G, Ada describes an algorithm for the analytical engine to compute Bernoulli numbers. It is generally considered the first algorithm ever specifically tailored for implementation on a computer, and for this reason she is considered by many to be the first computer programmer.
Note G could possibly also be said to be the first expression of the modern computer phrase "Garbage In, Garbage Out". Lovelace wrote
The Analytical Engine has no pretensions whatever to originate anything. It can do whatever we know how to order it to perform. It can follow analysis; but it has no power of anticipating any analytical relations or truths.