In 1840, 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 of Italy, wrote up Babbage's lecture in French, and this transcript was subsequently published in the Bibliothèque universelle de Genève in October 1842. Babbage's friendCharles Wheatstone commissioned Ada to translate Menabrea's paper into English. She then augmented the paper with notes, which were added to the translation. Ada spent the better part of a year doing this, assisted with input from Babbage. These notes, which are more extensive than Menabrea's paper, were then published inTaylor's Scientific Memoirs under the initialism AAL. In 1953, more than a century after her death, Ada's notes on Babbage's Analytical Engine were republished. The engine has now been recognized as an early model for a computer and Ada's notes as a description of a computer and software.^[61]

Her notes were labeled alphabetically from A to G. In note G, she describes an algorithm for the Analytical Engine to computeBernoulli numbers. It is considered the first algorithm ever specifically tailored for implementation on a computer, and Ada has often been cited as the first computer programmer for this reason.^[62][63] The engine was never completed, however, so her code was never tested.