An Illustrated History ofComputationProf Bernie Cohen FBCS
Blue plaque on his mothers house at 22 Ennismore Ave, Guildford
Computer science is no more about computers than astronomy is about telescopes. Simplicity and elegance are unpopular because they require hard work and discipline to achieve and education to be appreciated.Edsger W. Dijkstra 1930 – 2002
The Magic Number ZERO Introduced into Europe by the Scythian friar St Dyonisius Exiguus (aka Dennis the Humble) c. 470 – c. 544 who also introduced BC and AD into the calendar and whose fomula forcalculating the date of Easterwas adopted by Pope Paul I.
The Problem of Easter Victor 1, the first African Pope (189-199), who broke with the quatrodeciman Eastern bishops because Rome fixed Easter on a Sunday. Passover Nisan 14 King Oswald of Northumbria convened the Synod of Whitby to resolve theThe Celtic Church conflict had its ownformula for Easter William of Orange defeated James II at the Battle of the Boyne
Computors The Brunswiga calculatorJohn Napier Blaise Pascal1550 - 1617 1623 -1662 bones and his Pascaline and logarithms
Navigation, Longitude and Time Charles Babbage (1791-1871) " I wish to God these calculations had been executed by steam!" Sir John Herschel (1792-1871)
The Difference Engine, a special-purpose calculator designed to tabulate logarithms and trigonometricfunctions by evaluating finite differences to create approximating polynomials. The Analytical Engine, a Turing-complete, general purpose computer. As soon as an Analytical Engine exists, it will necessarily guide the future course of the science. Whenever any result is sought by its aid, the question will then arise: ”By what course of calculation can these results be arrived at by the machine in the shortest time?" Passages from the Life of a Philosopher, 1864
Augusta Ada Byron,Countess Lovelace 1815- - 1852
Breaking the Codes at Bletchley ParkEnigma and the Bombe Lorenz and Colossus
The Theory of Computation "On Computable Numbers, with an Application to the Entscheidungsproblem" Proc LMS 1936 The Turing Machine, The Halting Problem, Artificial Intelligence David Hilbert Alan Mathison Turing 1862 - 1943 1912 - 1954 John von Neuman speculated about computers and theAlonzo Church human brain in analogies 1903 - 1995 sufficiently wild to be worthy of a medieval thinker, λ-calculus and Alan Turing thought about Recursion John von Neumann criteria to settle the question of 1903 - 1957 whether machines can think, which we now know is about as Stored-program Architecture relevant as the question of Self-replicating Automata whether submarines can swim. Game Theory E. W. Dijkstra
The man who built Colossus Tommy Flowers 1905 - 1998 When you leave valves switched on, they dont burn out. I cant tell you how to do it , but I wouldnt do it like that. ca. 1966
More British Pioneers William Shockley, Bell Labs, inventor of the junction transistor (1951), the man who brought silicon to Silicon Valley born London 1910 Freddie Williams, U. of Manchester, inventor (with Tom Kilburn) of the Ernest Kaye, died April 21, 2012, Williams Tube, the first electronic last surviving member of the team storage device, used in the that built the Lyons Electronic Office, Ferranti Mark 1, 1951... 1951, the worlds first business computer. … the worlds first commercially available electronic computer, built by a team includng Maurice Wilkes, Christopher Strachey andTim Berners-Lees parents.
Self-Defeating TechnologyThe Blundell Vector Slide Rule (1952) and High Speed Electronic Circuits VLSI (Very Large Scale Integration) and the Swiss Watch Industry
Computers in Business The Elliott 153, Borehamwood, 1954At present four Government offices have been equipped with computers and orders have been placed for equipment for a further four. Studies of the possible use of computers in five more offices have almost been completed. Jocelyn Simon, Financial Secretary to the Treasury, House of Commons debate, June 26, 1958
Programming Languages Tom Kilburns Highest Common Factor routine, the first program run on theBaby, predecessor of the Machester Mark 1 and Ferranti Mark 1, 1948.
Programming Languages Coding in English??? DIVIDE CAKE INTO THREE” The use of COBOL cripples the mind; its teaching should, therefore, be regarded as a criminal offence. E. W. DijkstraGrace Murray Hopper, John W Backus, Peter Naur, USN, 1906 - 1992 IBM, 1924 - 2007 U Copenhagen, First compiler 1951 FORTRAN 1954 1928 - COBOL 1959 BNF : Backus-Naur (or Backus Normal) Form syntactic metalanguage in which the grammar of Algol 60 was fomally defined. Panini (ca. 550BC) constructed a formal grammar of Sanskrit, the Ashtadhyayi
Programming Languages BASIC, Darmouth College, NH, 1964John G. Kemeny Thomas E. Kurtz 1926 -1992 1928 -Manhattan Project with John von Neumann. Princeton PhD (TypeTheory vs Set Theory)under Alonzo Church.Mathematical assistant to Einstein. President of Dartmouth College. Chair of Three MIle Island commission It is practically impossible to teach good programming style to students that have had prior exposure to BASIC; as potential programmers they are mentally mutilated beyond hope of regeneration. E. W. Dijkstra
More Programming Languages Christopher Strachey 1916 - 1975 Scion of the Bloomsbury Group Designed Programming languages for Elliott and Ferranti. Creator of CPL, Christophers Programming Language, from which came BCPL, then B, then C, then Unix. First Prof of Computer Science at Oxford, founded denotational semantics, the formal theory of programming languages. John McCarthy 1927 -2011 Developed LISP at MIT in 1958:a Turing-complete language with a few simple operators and a notation for functions, which provided the foundation for Artificial Intelligence.
Formal Specification & Verification Formal syntax of a programming language defines all valid programs in a finite collection of recursive production rules. A programming language compiler generates executable code for each construct defined by a production rule. Formal semantics of a programming language defines the meaning of each construct as a logical relation between the states of the computation before and after its execution. Formal specification of a program is a logical relation that its execution should guaranteeRobin Milner, 1934 - 2010 betweeen its input and its output. Ferranti, Cambridge,Edinburgh, Stanford, etc. Verification of a program is the proofAutomatic theorem proving that its semantics satisfies it specification. ML, CCS, LCF, Many safety-critical systems are now pi-calculus. required to be formally verified.
Recursion and InvarianceDijkstras Ball Game The Mutilated Chessboard
Recursion and Induction: Proving that 1 + 1 = 2 The Theory NAT DefineSignature 0 as zz: NAT 1 as s zs: NAT → NAT 2 as s s zp : NAT, NAT → NAT + as pAxiomsp(z, n) = n .....................1 Proofp(s m, n) = s p(m, n)......2 1 + 1 = p(s z, s z) by definition = s p(z, s z) by axiom 2 =ssz by axiom 1 = 2 by definition
Minis and Mainframes The DEC PDP 8, 1965 up to 32K 12-bit words. 666KHz The IBM 360, 1964Up to 8Mb 32-bit words 1Mhz
Remote Batch Terminals Televideo 925, 1982 The sad tale of the sheriff and the IBM sales engineer
The Single Chip Microprocessor Intel 4004. 1970 Intel 8008, 1971 4kB in 4-bit words 16Kb in 8-bit words 2300 transistors 3500 transistors 740KHz 800KHz $200 $120
Personal ComputersHomebrew Computer Club, Silicon Valley The MITS Altair 8800, 1975 $400 kits for electronics hobbyists. 10,000 kits shipped No software Microsoft founded to supply a BASIC interpreter. CP/M OS added later.Processor Technology Sol-20, 1977 IBM Blue case and walnut sidesVideo and tape I/O interface boards built-in. Designed by Lee Felsenstein.Kansas City data transfer standard.
The 1977 Trinity Commodore PET Chuck Peddle TRS-80 Apple II Radio ShackSteve Wozniakand Steve Jobs
Xerox PARC The Xerox 914 copier, 1959, generated so much profit that, in 1970, Xerox founded a non-profit research lab in Palo Alto with instructions not to make product. The Xerox Alto, 1973 A personal computer with mouse, graphical user interface and ethernet. Inspired Steve Jobs to design the Apple Mac.The Xerox 8010 Star (or Dandelion), 1981 $16,595 Powered by a Symbolics LISP chip. Rejected as a product line by Xerox.
Personal Computers Atari 400, 1979 The original games machine The IBM PC, 1981 4 million sold 4.77MHz Intel 8088, up to 256Kb RAM IBM thought of buying the 2 floppy disk drives, open architecturecompany to get it, but instead Operating system MS-DOS by Microsoft designed ... based on QDOS, based on CP/M $1565
Home Computers Commodore 64, 1982 17 million sold BBC Model A/B, 1981 Acorn (ARM) Millions sold Amstrad CPC464, 1984 Sinclair ZX Spectrum, 1982 3 million sold5 million sold (not including clones)
WIMP Windows, Icons, Mice and PointersApple Macintosh, 1984 8MHz Widows 1.0 1985, Motorola 68000 2 years late, slow and buggyMacPaint, MacWrite, Mac Draw Windows 2.0 1987 128k, $2495 Mac look-alike, 256k, $2795 Aldus Pagemaker, Excel, Word, Corel Draw
Meanwhile … on the telephone Alexander Almon Brown Graham Bell Strowger 1847 - 1922 1839 - 1902 Prof of Elocution Undertaker Telephony, First exchange aeronautics, La Porte, IN, 1892 hydrofoil and 75 subsribers many other First UK autopmatic inventions. exchange Bell Labs. Epsom, 1912 In 1876, the President of Western Electric declined to buy Bells patent for $100,000, claiming that the telephone was just a toy. Two years later, he offered $2,000,000 for it.
Stored Program Controlled Telephone Switching First in Europe 10CX, 1967 ITT BTM Wilrijk, Belgium First digital exchange in world Moorgate PCM, 1971 London First in world ITT STC No. 1 ESS, 1965AT&T Western Electric Succasunna, NJ
Convergence with Telecoms Alec Reeves Vint Cerf Martin Cooper Pulse code TCP/IP on Motorola DynaTac (The Brick)modulation. 1937 Arpanet, 1972 1973 Tim Berners-Lee Apple Hypertext, 1980 iPad 4s plus Internet 2012 = WWW, 1989
Ubiquitous Computing Moses, meet Steve. Hes going to upgrade your tablet.