Back in 1837, the first 'modern' computer was conceived (100 years before Turing defined what a computer is). Charles Babbage's Analytical Engine was steam powered, but conceptually remarkably similar to modern computers. It has memory, a programmable processor, and even pipe-lining! Sadly it was never finished.
There's a project getting underway to build the Analytical Engine, which is the size of a truck! http://plan28.org/
They need 50000 pledges of £10 to get the project started. Pledge at http://www.pledgebank.com/babbage
