I agree. It's an orrery. It's not something we would call a computer today, however amazing it is. Babbage's Difference Engine wasn't a computer in that sense too. The Difference Engine is more like an ALU. Today, two Difference Engines are in existance, one is in the science museum in London, the other one will be shipped to some MicroSoft billionaire anytime soon. The machine is about GBP 1 million. Babbage's Analytical Engine, however, that's what we would call a computer today. A real nice box of tricks. The Analytical Engine was somewhat bigger and somewhat more complex. For example, the difference engine is an adding machine. This in itself is enough to make a computer out of, but the AE also had dedicated mechanisms to multiply and divide 50 digit decimal numbers in about 3 minutes upon request of a punched card. Babbage also got rid of the ripple carry we all learn about in elementary school and created something that could add the same 50 digit numbers in 2 steps (adding all numbers, then adding all carries at once by linking 9's next to each other mechanically). I've no idea what it would cost to make it today. It was also never finished, but part of the ALU has been built by Babbage (and later his son did some work too). Babbage called the ALU the mill and the memory the store, concepts that were taken from the weaving industry. He also used somthing similar to the Jacquard loom to read the punched cards.