Imagine a man in the early 1800s trying to build a programmable computer out of steam, brass, and gears, dying considered a total crank, and leaving behind only unfinished machines. Then, over a century later, scientists built his design from his original blueprints, and it worked flawlessly.

This episode traces Charles Babbage, the father of the computer, who conceptualized the fundamental architecture of the modern machine more than a century before the electronic age, and whose brilliance was constantly sabotaged by his own abrasive personality.

• The Difference Engine, the method of finite differences, and how a falling-out with engineer Joseph Clement collapsed the project after 17,000 pounds of funding
• The Analytical Engine with its mill and store, programmed by punched cards borrowed from the Jacquard loom
• Ada Lovelace’s collaboration and her Bernoulli numbers algorithm, plus the debate over credit
• His scattershot genius: the train cowcatcher, the ophthalmoscope, breaking the Vigenere cipher, and his bizarre war on street musicians
• The 1991 triumph, when the Science Museum built Difference Engine No. 2 to 19th-century tolerances and it calculated to 31 digits without error