[tsimionescu]

> I think you're missing the central point, which is that computation is observer relative. Anything can be interpreted as a computational process.

This is completely wrong. The opposite is true: computation is a mechanical process, it does not depend on an observer giving it meaning. It's true that the same mechanical process can be interpreted as different computations, but they will have the exact same computational properties (e.g. complexity), only the result will be interpreted differently.

In particular, it is extremely unlikely that the wall is implementing Word Star, because WordStar is a highly structured computation. The wall MIGHT be implementing some very simple additions, and essentially any process is implementing any one step computation.