A Turing Machine built using LEGO

<a href="http://news.ycombinator.com/item?id=4126210" rel="nofollow">http://news.ycombinator.com/item?id=4126210</a><p>As I said there, I'm always deeply disappointed (less deeply as time goes by, I'm coming to expect it) when something like this in Lego is actually just a peripheral for a program running in silicon somewhere.<p>I no longer have any of my Lego, but I remember building most of a completely mechanical Turing Machine way back in the early 1970s. So satisfying seeing it work purely mechanically, and I'm sure someone with more creativity and skill than I had, or indeed have, could do it.<p>Please?

Inaccurate. This isn't a Turing machine built using Lego. It's some simple memory which is then used by the Lego mindstorms CPU.

I always find these physical Turing machines kind of silly. The Turing machines and UTM are theoretical devices used to solve a problem in mathematical logic.<p>Also, this particular machine isn't a UTM. It doesn't read its program from the tape, and therefore it's useless IMHO.<p>Now, if someone wants to build a UTM using the symbols and state transitions described in Turing's original paper then that would be worth looking at.

Instructions for how to build it would be nice. I see source code for the NXT brick, but no diagrams.