Quite amazing. I hope he builds some more computer parts out of wood.

… a few months ago, I had an idea as to how the divide by two mechanisms from my first marble machine could be cascaded together to actually function as a sort of adder or counter. Once I had that idea, I knew I had to try it at some point, and recently, I finally got around to building my marble binary adding machine.

[via MAKE]
Binary marble adding machine