How did this programmer achieve this calculator inside of a game?

Link here: YouTube Video

I'm curious and thinking for a long time now I have no idea how this man pulled it off. I just see levers and thread going a开发者_运维问答nd coming into cogs at random so it seems.

Can someone shed some light for us curious geeks. :)

He seems to have programmed the calculator by simulating gates using in-game mechanisms (I'm kind of rusty on this topic but see this for reference). So in a way, the game itself is somewhat of a hardware simulator in this case.

d03boy: Little Big Planet allows players to design their own levels, essentially programming the game environment with in-game objects that simulate physical ones.

To answer the question, it looks to me like the level designer created a virtual adding machine using in-game objects. Pretty neat, if you ask me.