1. Ten Interesting Computer Scientists Dr. Raymond Greenlaw Armstrong Atlantic State University School of Computing

2. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing2 Outline History of Computer Science John Backus Stephen Cook Seymour Cray Edsger Dijkstra Bill Gates Alan Kay Donald Knuth Leslie Lamport John McCarthy Alan Turing

3. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing3 History of Computer Science 1673 – Gottfried Wilhelm von Leibniz invents a machine to do multiplication 1821 – Charles Babbage builds a machine to calculate exponential functions, begins designing Analytical Engine 1832 – Ada Lovelace begins writing programs (on punch cards) for the nonexistent Analytical Engine, inventing such concepts as loops and subroutines 1935 – Alan Turing defines a model for computation

4. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing4 History of Computer Science 1937 – Claude Shannon links Boolean logic to digital circuit design 1939 – Turings work plays a key role in breaking the Germans Enigma code machine 1943 – Small computers are being built in multiple countries 1950 – Turing proposes a test of machine intelligence, the Turing test 1956 – John McCarthy coins the term artificial intelligence

5. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing5 History of Computer Science 1957 – FORTRAN is released by John Backus and the IBM team 1958 – John McCarthy invents Lisp 1959 – John Backus and Peter Naur propose the use of context-free grammars to describe programming languages 1961 – Edsger Dijkstra applies the semaphore principle used in train signaling systems to mutual exclusion in computer operations

6. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing6 History of Computer Science 1962 – Donald Knuth begins work on The Art of Computer Programming 1971 – Alan Kay develops the first object- oriented programming language, Smalltalk 1971 – Stephen Cook publishes a paper on non-deterministic polynomial completeness (NP-completeness), defining a new family of problems that is not computable in a practical sense

7. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing7 History of Computer Science 1973 – Leonid Levin publishes a paper identifying the class of NP-complete problems independently of Cook (research was conducted in 1971) 1977 – Leslie Lamport defines a model of time for distributed systems based on a partial order of events 1980 – Microsoft is founded, helping to push PCs into widespread use with the public

8. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing8 John Backus We simply made up the language as we went along. We did not regard language design as a difficult problem, merely a simple prelude to the real problem: designing a compiler which could produce efficient programs...

9. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing9 Biography - John Backus 1949 – Graduated from Columbia University with a B.S. in Mathematics 1950 – Joined IBM and worked on the SSEC (Selective Sequence Electronic Calculator) for three years Collaborated with Peter Naur to create Backus-Naur Form Developed FP which helped push functional programming Retired in 1991

10. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing10 Achievements - John Backus Designer of FORTRAN Backus-Naur Form Designed FP, a functional programming language 1977 – Turing Award winner 1987 – named an IBM Fellow 1993 – awarded a Draper Prize

11. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing11 Trivia - John Backus Has a plate in his head of his own design after having a bone tumor Roughly half the work of designing FORTRAN went into generating efficient machine code After retiring in 1991, has completely withdrawn from computer science Practices meditation

12. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing12 Stephen Cook The idea that there wont be an algorithm to solve itthis is something fundamental that wont ever changethat idea appeals to me.

13. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing13 Biography - Stephen Cook 1961 – B.S. in Mathematics from University of Michigan 1962, 1966 – M.S. and Ph.D. in Mathematics from Harvard 1966-1970 – Assistant Professor, University of California, Berkeley 1970 – Joined University of Toronto as Associate Professor, Professor in 1975, and University Professor of Computer Science and Mathematics in 1985

14. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing14 Achievements - Stephen Cook Formalized the notion of NP-completeness Cooks Theorem – concerns itself with reducing NP-complete problems to a general Satisfiability problem 1977 – Steacie Fellowship 1982 – Turing Award winner Fellow of Royal Society of Canada

15. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing15 Seymour Cray "If you were plowing a field, which would you rather use: Two strong oxen or 1024 chickens?"

16. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing16 Biography - Seymour Cray 1950 – B.S. in Electrical Engineering, University of Minnesota 1951 – Awarded a M.S. in Applied Mathematics, University of Minnesota 1950 – Joined Engineering Research Associates 1960 – Joined Control Data Corporation 1965 – The CDC 6600, the first commercial supercomputer, is released 1972 – Founded Cray Research

17. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing17 Biography - Seymour Cray 1976 – The Cray-1 is released 1980 – Cray steps down as CEO of Cray Research and becomes an independent contractor 1989 – Founded Cray Computer Corporation 1995 – Set up SRC Computers, Inc 1996 – Died in a car accident

18. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing18 Achievements - Seymour Cray Founder of Cray Research and Cray Computer Corporation Released the first commercial supercomputer Designed computers concerned with total computing speed Worked hard to improve I/O bandwidth as opposed to just concentrating on processor speed

19. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing19 Trivia - Seymour Cray The vehicle Cray was driving when he died, a Jeep Cherokee, was designed on a Cray supercomputer In 1986, Apple bought a Cray X-MP and announced it would be used to design the next Macintosh, Cray replied that he was using a Macintosh to design the Cray-2 supercomputer

20. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing20 Edsger Dijkstra "Computer Science is no more about computers than astronomy is about telescopes."

21. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing21 Biography - Edsger Dijkstra Studied physics at the University of Leiden 1970s – Worked as a research fellow for Burroughs Corporation Worked at the Eindhoven University of Technology in the Netherlands Held the Schlumberger Centennial Chair in Computer Sciences at the University of Texas at Austin Retired in 2000 Died August 6, 2002

22. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing22 Achievements - Edsger Dijkstra Dijkstras algorithm (shortest path) which has been used to solve numerous routing problems The semaphore construct which helped solve the problem of critical regions Formulated the dining philosophers problem 1972 – Turing Award winner Has archive of technical papers at University of Texas at Austin

23. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing23 Trivia - Edsger Dijkstra At age 12, attended Gymnasium Erasminium, an elite Dutch high school Go To Statement Considered Harmful was the revised title by Niklaus Wirth (then editor of CACM), originally titled A case against the goto statement On team to invent first compiler for ALGOL 60, made a deal with collaborator not to shave until project was complete, kept the beard until his death

24. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing24 Trivia - Edsger Dijkstra Dining Philosophers Imagine that five philosophers are sitting around a table. Before each is a bowl of rice and a chopstick to either side of the bowl. The rules for dining: –Each philosopher thinks for a while, eats for a while, and then waits for a while –To eat, he must hold both his right and left chopstick –They only communicate by lifting and lowering their chopsticks

25. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing25 Trivia - Edsger Dijkstra Dining Philosophers In order to eat, the following algorithm must be utilized: –Pick up the right chopstick when available (wait if right neighbor has it) –Pick up the left chopstick when available (wait if left neighbor has it) –Eat Using this algorithm, a few scenarios can occur leading to certain situations

26. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing26 Trivia - Edsger Dijkstra Dining Philosophers Deadlock occurs when all philosophers decide to eat at the same time, they succeed at the first step, but wait forever at the second Starvation can occur for other philosophers if one philosopher never releases his chopsticks Even if all eat, some may eat more than others which can cause lack of fairness

27. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing27 Bill Gates "The best way to prepare [to be a programmer] is to write programs, and to study great programs that other people have written. In my case, I went to the garbage cans at the Computer Science Center and fished out listings of their operating system."

28. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing28 Biography - Bill Gates 1975 – Founded Microsoft with Paul Allen after developing a version of BASIC that ran on Altair systems 1976 – Wrote an article denouncing people who used software and didnt pay for it, helped push closed-source development, after openly admitting he took source code from dumpsters 1980 – Sold IBM a relabeled version of QDOS, known as PC-DOS

29. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing29 Biography - Bill Gates Early 1980s – Aggressively marketed MS- DOS to PC clone manufacturers Late 1980s – Microsoft Windows began to be preinstalled on a number of PCs 1990 – Windows 3.0 is released 1998 – Gates steps down as CEO of Microsoft, but continues to serve as Chairman of the Board and Chief Software Architect

30. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing30 Achievements - Bill Gates Helped port BASIC to the Altair Co-founded Microsoft with Paul Allen Chairman and Chief Software Architect of Microsoft Provided a GUI operating system to many PC clone manufacturers Has positioned Microsoft as the leading software company in the world

31. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing31 Trivia - Bill Gates Dropped out of Harvard in his third year to pursue software development Attained the rank of Life Scout in the Boy Scouts of America Named wealthiest person in the world by Forbes magazine for several years Has a house in Washington valued at over $113 million, all visitors get a microchip that adjusts temperature and other conditions to their preferences

32. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing32 Alan Kay All understanding begins with our not accepting the world as it appears.

33. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing33 Biography - Alan Kay 1966 – B.S. in Mathematics and Molecular Biology, University of Colorado 1969 – M.S. in Electrical Engineering, Ph.D. in Computer Science, University of Utah 1970 – Professor, Stanford Artificial Intelligence Laboratory 1972 – Group Leader, Xerox Palo Alto Research Center 1984 – Apple Fellow, Apple Computers

34. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing34 Achievements - Alan Kay Designer of Smalltalk Coined the term object-orientation Conceived the laptop computer Architect of the modern windowing GUI 2001 – UdK 01-Award winner 2003 – Turing Award winner 2004 – Kyoto Prize and Charles Stark Draper Prize winner

35. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing35 Trivia - Alan Kay Could read by the age of three Expelled from Bethany College for protesting the Jewish quota Made a living as a professional guitarist in the 1960s Used his degree in molecular biology to help form the basic ideas of OOP Very interested in using computers to further education

36. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing36 Donald Knuth Computer programming is an art form, like the creation of poetry or music.

37. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing37 Biography - Donald Knuth In 8 th grade, won competition by composing words from Zieglers Giant Bar; Knuth found 4,500 in two weeks of feigning illness, the judges master list had 2,500, has said he would have found more if he had thought to use the apostrophe Graduated from high school in 1956 with the highest GPA ever achieved at that school

38. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing38 Biography - Donald Knuth Graduated in 1960 from Case Institute of Technology with a B.S. in Mathematics, was simultaneously awarded an M.S. for his achievements, an unprecedented move Received a Ph.D. in Mathematics from California Institute of Technology in 1963 Joined Stanford University as a Professor of Computer Science in 1968 In 1993, became Professor Emeritus of The Art of Computer Programming at Stanford, where he is still currently located

39. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing39 Achievements - Donald Knuth Authored The Art of Computer Programming, a multi-volume tome on CS Inventor of TeX and METAFONT LR(k) parsing Knuth-Morris-Pratt algorithm 1974 – Turing Award winner 1979 – National Medal of Science 1995 – John von Neumann Medal

40. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing40 Trivia - Donald Knuth The Art of Computer Programming began as a text about compilers Loves organ music, mostly 4 and 8-hand music which he plays on an organ in his home, he studied piano as a child Pays $2.56 (one hexadecimal dollar) for errors found in his books Quit using email in 1990 Processes all communications in batch- mode

41. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing41 Leslie Lamport A distributed system is one in which the failure of a computer you didnt even know existed can render your own computer unusable.

42. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing42 Biography - Leslie Lamport 1960 – B.S. in mathematics, Massachusetts Institute of Technology 1963 – M.A., Brandeis University 1972 – Ph.D., Brandeis University 1970-1977 – Massachusetts Computer Associates 1977-1985 – SRI International 1985-2001 – Digital Equipment Corporation/Compaq 2001-Present – Works for Microsoft

43. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing43 Achievements - Leslie Lamport Bakery Algorithm – an improvement to Djikstras semaphore idea, which involves each participant getting a ticket Lamport Clocks – A relative time idea used in distributed computing Developed a technique using digital signatures to aid in fault-tolerant systems Designer/developer of LaTeX, a macro system that sits on top of Knuths TeX and is used by many scientists for papers

44. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing44 Trivia - Leslie Lamport LaTeX started as a side project to improve the new version of TeX introduced in 1982, Lamport estimates he spent about 10 months developing LaTeX Very modest about his involvement with many of his ideas, saying most of it seems like dumb luckI happened to be looking at the right problem, at the right time, having the right background.

45. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing45 John McCarthy If you want the computer to have general intelligence, the outer structure has to be commonsense knowledge and reasoning.

46. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing46 Biography - John McCarthy 1948 – B.S. in Mathematics from the California Institute of Technology 1951 – Ph.D. in Mathematics from Princeton Short-term appointments at Princeton, Stanford, Dartmouth, and MIT 1962 – Full Professor at Stanford University Retired at the end of 2000, is now Professor Emeritus

47. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing47 Achievements - John McCarthy Coined the term artificial intelligence in 1955 at the Dartmouth Conference Designer of LISP, the principle language of artificial intelligence 1961 – First to propose publicly the selling of computing as a utility, like electricity or water 1962 – Set up the Stanford AI Laboratory 1971 – Turing Award winner

48. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing48 Trivia - John McCarthy As a high school junior, bought the calculus books used for freshman and sophomore math, worked out all the exercises which allowed him to skip the first two years of math when he attended the school in 1944 Like Backus and Kay, eventually lost control over the language (LISP) he invented

49. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing49 John McCarthy LISP – list processing language All lists are contained within parentheses (A B C), with the elements as atoms Supports recursion and has an eval operation to define new functions and execute them as part of that program CAR returns the first element of the list, (CAR (A B C)) returns A CDR returns a list with everything but the first element, (CDR (A B C)) returns (B C)

50. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing50 Alan Turing …I believe that at the end of the century the use of words and general educated opinion will have altered so much that one will be able to speak of machines thinking without expecting to be contradicted.

51. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing51 Biography - Alan Turing 1934 – Graduated from Kings College, Cambridge with a distinguished degree 1935 – Elected a Fellow at Kings 1938 – Received his Ph.D. from Princeton During WWII worked at Bletchley Park, his work there was kept secret until the 1970s 1945-1947 – Worked on the design of ACE (Automatic Computing Engine) at the National Physical Laboratory

52. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing52 Biography - Alan Turing 1949 – Became deputy director of the computing laboratory at the University of Manchester 1952-1954 – Worked on mathematical biology 1954 – Died of cyanide poisoning from a half-eaten apple, death ruled a suicide

53. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing53 Achievements - Alan Turing Often considered to be the father of modern computer science Turing Test Turing Machine Church-Turing Thesis Worked at Bletchley Park during WWII Invented an electromechanical machine which could find settings for Enigma Created one of the first designs for a stored program computer

54. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing54 Trivia - Alan Turing Said to have taught himself to read in three weeks At age 14, rode a bike 60 miles to attend his first day at Sherborne School Was gay during a time when it was illegal, many believe this led to his security clearance being revoked, and possibly his death Was forced to undergo hormonal treatment in lieu of prison

55. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing55 Conclusions This is only a small sampling of people who have contributed greatly to the field of computer science. We would like to thank the many others who havent been recognized, but have given greatly to our pool of knowledge. The future is bright, there are many active fields of research, and we look forward to acknowledging other pioneers in computer science.

56. Dr. Raymond Greenlaw – Armstrong Atlantic State University – School of Computing56 References Computer Science: Prof Cook. Cook, Stephen. November 2005 Dewdney, A.K. The New Turing Omnibus. New York: Henry Holt and Company, 1989. Don Knuths Home Page. Knuth, Donald. November 2005 Knuth, Donald. The Art of Computer Programming. United States of America: Addison-Wesley Pub Co, 1997. Knuth, D. E. and Bendix, P. B. "Simple Word Problems in Universal Algebra." In Computational Problems in Abstract Algebra (Proc. Conf., Oxford, 1967). Pergamon Press, pp. 263-297, 1970. Shasha, Dennis Elliott. Out of their minds: the lives and discoveries of 15 great computer scientists. New York: Copernicus, 1995. Winston, Patrick Henry. LISP. Reading: Addison-Wesley Publishing Company, 1984. Multiple Articles, November 2005