Alan Turing was a rather clever sort, who did a lot of work in mathematics, logic, computer science, and code breaking. He also played Go and wrote down a set of rules for the game. Alan Turing's exact formulation, in his own handwriting, can be viewed at the Turing Archive where it is under copyright AND THUS NOT REPRODUCED HERE. They are written on a King's College's notepaper, which should date them as being written at some time between 1931 and 1934.
Essentially, the rules describe No Pass Go, which has been also known as nimgo. Rule 5 appears to be better deleted, since it is a subset of the second phrasing of Rule 7. Rule 6 deals with ko. It can probably be viewed as malformed, since it does not take account of snapback, and thus has something of a Tibetan feel.
Alan Turing played with I.J.Good, who authored an article on the game which was published in New Scientist.
See wikipedia entry.