Augusta Ada King, Countess of Lovelace (née Byron; 10 December 1815 – 27 November 1852) wrote the first real computer program , about 100 years before the first digital computer existed. Her and her husband William King, Earl Lovelace, lived in Surrey. They commissioned the building of Horsley Towers, a magnificent gothic mansion near Guildford.
The Cambridge mathemetician and inventor Charles Babbage designed a number of mechanical calculating devices including the Analaytical Engine. He never managed to get his machine working, but versions have been built since. This video explains the principles: Had he succeeded, the Engine would have been the first programmable digital computer.
Countess Lovelace, one of few women trained in mathematics, worked with Babbage and she wrote and published the first real computer program. She was the first of many women to do pioneering work in Computer Science.
Background notes for this talk can be downloaded here.
The speaker Simon Ritchie has been a computer programmer throughout his career in computing. He also runs the Surrey History Meetup, an online forum that aims to promote events in Surrey involving history. See here for details of the Meetup.