Harry NelsonHarry Lewis Nelson (born January 8, 1932) is an American mathematician and computer programmer with degrees in mathematics from Harvard University and Kansas University. Most of his professional career was spent at Lawrence Livermore National Laboratry where he worked with some of the earliest supercomputers. He was particularly noted as one of the world's foremost experts in writing optimized assembly language routines for the Cray-1 and Cray X-MP computers. He was a member of the team that won the World Computer Chess Championship in 1983 and 1986, and was a co-discoverer of the 27th Mersenne prime in 1979 (at the time, the largest known prime number). Mathematics is recreation to Harry. In fact, he served as editor of the Journal of Recreational Mathematics for five years and as Emeritus Editor, for subsequent years. Harry has had a lifelong interest in puzzles of all types, and since his retirement in 1991 he has devoted his time to his own MiniMax Game Company, a "think tank" for games and puzzles. There are currently 20 mechanical puzzles and/or games on the U.S. market for which he has made substantial contributions, including RUSH HOUR(R) and Cool Circuits(TM). Read More Read Less