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Another technical opinion on building the Analytical Engine

I wrote to Tony Hoare to ask his opinion on this idea and he was kind enough to reply:

Would you be interested in doing an animation of the engine first? I've much enjoyed computer animations of the old Elliott 803, with the original tape decks, paper tape readers and punches, and all making the right motions and the right noises! Of course I also like revisiting the real machine, even if stationary.

The simulation would be a good way of collecting money and enthusiasm for the real Engine. But the trouble with the real thing is that if you demonstrate it, it will wear out. OK for a private owner, but a bit disappointing as a museum piece -- unless supported by simulations.

I assure you that even if the real thing is built, the simulation will be essential to check the design before construction can begin. And it will be the main intellectual challenge in the project -- and great fun.

Clearly, he's correct. The first step in building the Analytical Engine would be to create a working prototype on a computer so that bugs in its design (which will need to be reconstructed from fragments and incomplete descriptions) can be worked out and a viable machine created in some CAD package.

From that a real machine could be created. Looking at the plans for the Analytical Engine the minimum machine would likely to quite large: around the size of a steam locomotive.

So, any experts on building this type of simulation out there?

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