Computer Go is one of the most challenging topics studied in the field of Artificial Intelligence. The reason for this is that the brute-force methods, so successful in Computer Chess, will not work for Go. This offers researchers a new challenge and opens up a very wide scope of possibilities for AI programming. This paper contains the data structures and algorithms used to design the Computer Go program — Archmage 1.1 During the Computer Go contest in Japan in August 1991 and the 4th Computer Olympiad in London in August 1992, Archmage attracted a lot of attention due to its competent strength.