Harry L. Nelson | |
---|---|
Born | January 8, 1932 Topeka, Kansas |
Died | May 14, 2024 |
Known for | Co-creation of "Cray Blitz" |
Harry Lewis Nelson (born January 8, 1932) is an American mathematician and computer programmer. He was a member of the team that won the World Computer Chess Championship in 1983 [1] and 1986, [2] and was a co-discoverer of the 27th Mersenne prime in 1979 [3] (at the time, the largest known prime number). He also served as editor of the Journal of Recreational Mathematics for five years. Most of his professional career was spent at Lawrence Livermore National Laboratory 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. Nelson had a lifelong interest in puzzles of all types, and founded the MiniMax Game Company, a small venture that helps puzzle inventors to develop and market their products.
In 1994, Nelson donated his correspondence from his days as editor of the Journal of Recreational Mathematics to the University of Calgary Library as part of the Eugène Strens Recreational Mathematics Special Collection. [4]
Nelson was born on January 8, 1932, in Topeka, Kansas, the third of four children. He attended local schools and was active in the Boy Scouts, earning the rank of Eagle Scout. Nelson attended Harvard University as a freshman, but then had to drop out for financial reasons. He attended the University of Kansas as a sophomore, but was able to return to Harvard for his junior and senior years, receiving a bachelor's degree in mathematics from Harvard in 1953. In 1952, just before the start of his senior year, he married his high school sweetheart, Claire (née Rachael Claire Ensign). After graduating, he was inducted into the U.S. Army, but was never deployed overseas. He was honorably discharged in 1955, having attained the rank of sergeant. He enrolled in graduate studies at the University of Kansas, earning a master's degree in mathematics in 1957. It was during this period that he became fascinated by the then-new programmable digital computer. Nelson worked towards a Ph.D. until 1959, but the combination of his GI Bill educational benefits running out, needing to support a wife and three children, and the mathematics department rejecting his proposal to do his thesis on computers convinced him to leave the university without completing his Ph.D., and to get a job. [5]
Initially, Nelson worked for Autonetics, an aerospace company in southern California. In 1960 he went to work for the Lawrence Radiation Laboratory (later renamed Lawrence Livermore National Laboratory or LLNL), in Livermore, California. He remained working there until his retirement in 1991. Nelson worked on a variety of computers at LLNL, beginning with the IBM 7030 (nicknamed Stretch). In the 1960s, early units of a new computer were typically delivered as "bare metal," i.e. no software of any kind, including no compiler and no operating system. Programs needed to be written in assembly language, and the programmer needed to have intimate and detailed knowledge of the machine. A lifelong puzzle enthusiast, Nelson sought to understand every detail of the hardware, and earned a reputation as an expert on the features and idiosyncrasies of each new machine. Over time he became the principal person at LLNL in charge of doing acceptance testing of new hardware. [6]
During the process of acceptance testing, a new supercomputer would typically run diagnostic programs at night, looking for problems. During the acceptance testing of LLNL's first Cray-1 computer, Nelson teamed up with Cray employee David Slowinski to devise a program that would hunt for the next Mersenne prime, while simultaneously being a legitimate diagnostic program. On April 8, 1979, the team found the 27th Mersenne prime: 244497 - 1, the largest prime number known at that time. [7] [8]
In 1980, Nelson came across a copy of the chess program Cray Blitz written by Robert Hyatt. Using his detailed knowledge of the Cray-1 architecture, Nelson re-wrote a key routine in assembly language and was able to significantly speed up the program. The two began collaborating along with a third team member, Albert Gower, a strong correspondence chess player. In 1983, Cray Blitz won the World Computer Chess Championship, and successfully defended its title in 1986. [9]
The 1986 Championship was marred by controversy when the HiTech team, led by Hans Berliner, accused the Cray Blitz team of cheating. The charge was investigated for a few months by the tournament director, David Levy, and dismissed. [10] Despite the dismissal, the experience somewhat soured the computer chess scene for Nelson, although he remained active until the ACM discontinued the annual computer chess tournaments in 1994.
Nelson was active with the International Puzzle Party, and was a longtime contributor to the Journal of Recreational Mathematics. He served as Editor of the Journal for 5 years, and sat on its editorial board for many years after stepping down as Editor. [11]
Recreational mathematics is mathematics carried out for recreation (entertainment) rather than as a strictly research-and-application-based professional activity or as a part of a student's formal education. Although it is not necessarily limited to being an endeavor for amateurs, many topics in this field require no knowledge of advanced mathematics. Recreational mathematics involves mathematical puzzles and games, often appealing to children and untrained adults and inspiring their further study of the subject.
A supercomputer is a type of computer with a high level of performance as compared to a general-purpose computer. The performance of a supercomputer is commonly measured in floating-point operations per second (FLOPS) instead of million instructions per second (MIPS). Since 2022, supercomputers have existed which can perform over 1018 FLOPS, so called exascale supercomputers. For comparison, a desktop computer has performance in the range of hundreds of gigaFLOPS (1011) to tens of teraFLOPS (1013). Since November 2017, all of the world's fastest 500 supercomputers run on Linux-based operating systems. Additional research is being conducted in the United States, the European Union, Taiwan, Japan, and China to build faster, more powerful and technologically superior exascale supercomputers.
The Cray-1 was a supercomputer designed, manufactured and marketed by Cray Research. Announced in 1975, the first Cray-1 system was installed at Los Alamos National Laboratory in 1976. Eventually, eighty Cray-1s were sold, making it one of the most successful supercomputers in history. It is perhaps best known for its unique shape, a relatively small C-shaped cabinet with a ring of benches around the outside covering the power supplies and the cooling system.
Lawrence Livermore National Laboratory (LLNL) is a federally funded research and development center in California, United States. Originally established in 1952, the laboratory now is sponsored by the United States Department of Energy and administered privately by Lawrence Livermore National Security, LLC.
Floating point operations per second is a measure of computer performance in computing, useful in fields of scientific computations that require floating-point calculations.
Blue Gene was an IBM project aimed at designing supercomputers that can reach operating speeds in the petaFLOPS (PFLOPS) range, with relatively low power consumption.
Cray Inc., a subsidiary of Hewlett Packard Enterprise, is an American supercomputer manufacturer headquartered in Seattle, Washington. It also manufactures systems for data storage and analytics. Several Cray supercomputer systems are listed in the TOP500, which ranks the most powerful supercomputers in the world.
Henry Ernest Dudeney was an English author and mathematician who specialised in logic puzzles and mathematical games. He is known as one of the country's foremost creators of mathematical puzzles.
Crafty is a chess program written by UAB professor Robert Hyatt, with development and assistance from Michael Byrne, Tracy Riegle, and Peter Skinner. It is derived from Cray Blitz, winner of the 1983 and 1986 World Computer Chess Championships. Tord Romstad, co-author of Stockfish, described Crafty as "arguably the most important and influential chess program ever".
Marjorie Ruth Rice was an American amateur mathematician most famous for her discoveries of pentagonal tilings in geometry.
The CDC STAR-100 is a vector supercomputer that was designed, manufactured, and marketed by Control Data Corporation (CDC). It was one of the first machines to use a vector processor to improve performance on appropriate scientific applications. It was also the first supercomputer to use integrated circuits and the first to be equipped with one million words of computer memory.
Robert Morgan Hyatt is an American computer scientist and programmer. He co-authored the computer chess programs Crafty and Cray Blitz which won two World Computer Chess Championships in the 1980s. Hyatt was a computer science professor at the University of Southern Mississippi (1970–1985) and University of Alabama at Birmingham (1988–2016).
David Slowinski is a mathematician involved in prime numbers. His career highlights have included the discovery of several of the largest known Mersenne primes:
The Advanced Simulation and Computing Program (ASC) is a super-computing program run by the National Nuclear Security Administration, in order to simulate, test, and maintain the United States nuclear stockpile. The program was created in 1995 in order to support the Stockpile Stewardship Program. The goal of the initiative is to extend the lifetime of the current aging stockpile.
Donald Bruce Gillies was a Canadian computer scientist and mathematician who worked in the fields of computer design, game theory, and minicomputer programming environments.
Cray Blitz was a computer chess program written by Robert Hyatt, Harry L. Nelson, and Albert Gower to run on the Cray supercomputer. It was derived from "Blitz" a program that Hyatt started to work on as an undergraduate. "Blitz" played its first move in the fall of 1968, and was developed continuously from that time until roughly 1980 when Cray Research chose to sponsor the program. Cray Blitz participated in computer chess events from 1980 through 1994 when the last North American Computer Chess Championship was held in Cape May, New Jersey. Cray Blitz won several ACM computer chess events, and two consecutive World Computer Chess Championships, the first in 1983 in New York City, and the second in 1986 in Cologne, Germany.
Scalable POWERparallel (SP) is a series of supercomputers from IBM. SP systems were part of the IBM RISC System/6000 (RS/6000) family, and were also called the RS/6000 SP. The first model, the SP1, was introduced in February 1993, and new models were introduced throughout the 1990s until the RS/6000 was succeeded by eServer pSeries in October 2000. The SP is a distributed memory system, consisting of multiple RS/6000-based nodes interconnected by an IBM-proprietary switch called the High Performance Switch (HPS). The nodes are clustered using software called PSSP, which is mainly written in Perl.
The National Energy Research Scientific Computing Center (NERSC), is a high-performance computing (supercomputer) research facility that was founded in 1974. The National User Facility is operated by Lawrence Berkeley National Laboratory for the United States Department of Energy Office of Science.
IBM Sequoia was a petascale Blue Gene/Q supercomputer constructed by IBM for the National Nuclear Security Administration as part of the Advanced Simulation and Computing Program (ASC). It was delivered to the Lawrence Livermore National Laboratory (LLNL) in 2011 and was fully deployed in June 2012. Sequoia was dismantled in 2020, its last position on the top500.org list was #22 in the November 2019 list.