The greatest machine that never was - John Graham-Cumming 

Computer science began in the '30s ... the 1830s. John Graham-Cumming tells the story of Charles Babbage's mechanical, steam-powered "analytical engine" and how Ada Lovelace, mathematician and daughter of Lord Byron, saw beyond its simple computational abilities to imagine the future of computers. (Filmed at TEDxImperialCollege.)
Talk by John Graham-Cumming.