The following is a timeline of computer history, beginning with rudimentary counting aids and continuing up to our present time.
~300 B.C.
Although various primitive counting aids have doubtless been used by many cultures for thousands of years, the earliest surviving abacus was discovered in Babylonia from this time period.
~800 A.D.
The concept of the algorithm, a formal method for solving problems, is put forth by Muhammad ibn Musa Al'Khowarizmi. This would eventually form the basis of modern computer programming techniques.
1612
John Napier makes first printed use of the decimal point, and invents logarithms and several types of mechanical multiplication aids.
1622
William Oughtred invents the slide rule.
1623
William Schickard describes an adding machine with an automatic carry capability. However, none of his prototypes survived.
1642
Blaise Pascal is credited with inventing the first adding machine with automatic carry, the Pascalene.
1673
Gottfried Leibniz builds a calculator capable of multiplication by repeatedly adding a number into an accumulator, not unlike the use of registers in modern computers.
1801
Joseph-Marie Jacquard invents a loom which uses punched cards to control the pattern of the fabric.
1820
Charles Xavier Thomas de Colmar of France invents the Arithmometer, the first commercial mass produced calculating device. Allowing users to perform addition, subtraction, multiplication and division, it remains popular for the next ninety years.
1822
Charles Babbage recognizes the need for a computing machine for computing celestial and navigational tables. He devotes his life to designing the steam-powered Difference Engine.
1833
Babbage expands his work to a more general purpose computer, the Analytical Engine, in which he describes the basic components of modern computers.
1842
Ada Byron King, Countess of Lovelace, translates a description of the Analytical Engine, adding her own notes on programming the device, becoming the world's first programmer.
1847-1849
Babbage created several drawings for the design of the Difference Engine, but was unable to build the device due to technological limitations of the day. After his death, his son built the arithmetic logic unit for the device and sent copies of it around the world, including Harvard University.
1854
George Boole describes a system of symbolic logic that later becomes known as Boolean Algebra, a vital part of computer design.
1890
Herman Hollerith invents a data processing machine using punched cards for use in tabulating data in the 1890 U.S. Census. He founds a company to market these machines, Hollerith Tabulating Company. In later years punched computer cards are known as Hollerith cards.
1892
William Burroughs is granted a patent for one of the first practical and successful commercial calculators. His company later becomes the Burroughs Adding Machine Company.
1914
The Hollerith Tabulating Company merges with two other companies to form the Calculating-Tabulating-Recording (C-T-R) company.
1924
The C-T-R company is renamed IBM.
1925
Vannevar Bush of MIT invents the differential analyzer, which incorporates the functionality of a slide rule with the capability of calculating integration and differentiation.
1935-1938
Konrad Zuse of Berlin, Germany, invents a relay computer that uses binary arithmetic, the Z-1. In 1938 he completes the Z-2. Due to the war his inventions were not widely known until some years later. At the end of the war he moved to Switzerland where he built the Z-4. He also founded a computer company that would be absorbed into the Siemens Corporation.
1936-1939
John Vincent Atanasoff and John Berry invent the Atanasoff-Berry Computer (ABC) at Iowa State University. The ABC is the earliest example of an electronic calculator, and developed several primary concepts later used in the development of general purpose computers.
1937
Alan Turing describes the concept of a "Universal Machine," capable of executing any describable algorithm. Howard Aiken at Harvard University is also working on the problem of "computability" at this time. Also, George Stibitz at Bell Telephone Laboratories is investigating the possibilities of building a device that uses telephone switch relays to do arithmetic.
1939
Bell Telephone Laboratories builds the first electro-mechanical relay calculator, the Complex Number Calculator (later renamed the Bell Labs Model 1). This machine would later be used over telephone lines, setting the stage for the linking of telephone and computer into computer networks.
1940-1944
In an attempt to build a device to decrypt German messages encrypted with the ENIGMA encoder, a team at Bletchley Park, including Alan Turing, invent the Colossus Mark I, which is instrumental in decrypting messages during the end of the war. The existence of Colossus was classified until 1970, and the decryption algorithms remain classified today.
1943
John Mauchly and J. Presper Eckert at the University of Pennsylvania begin work on the Electronic Numerical Integrator and Computer (ENIAC).
1944
The first large scale, automatic general purpose electromechanical calculator, the Harvard Mark I, is built. The Mark I was based on design work done by Howard Aiken in the late 1930s, and was commissioned by the U.S. Navy to calculate mathematical and navigational tables, just as Babbage's Differential Engine was originally intended. In June 1944 Grace Hopper joins Aiken's team as the third "coder" on the Mark 1.
1945
While working on the Mark II, Grace Hopper finds a moth beaten to death in a relay, and glues it into the logbook. From then on, whenever the machine stops, the team tells Aiken they are "debugging" the system.
John von Neuman writes "First Draft of a Report on the EDVAC" in which he lays out the basic principles of modern computer architecture, including the stored program concept. This led to some controversy in later years, as Mauchly and Eckert claimed they had thought of these concepts prior to von Neuman joining the ENIAC team at the University of Pennsylvania. Later, Konrad Zuse claims to have had the same ideas in the 1930s.
1946
ENIAC is unveiled in Pennsylvania. However, it does not use the stored programming concept, instead depending on programming by rewiring connections between components. Later, after a patent dispute with the University of Pennsylvania, Mauchly and Eckert leave to form the Electronic Control Corporation to build the Universal Automatic Computer (UNIVAC). The company was taken over by Remington-Rand before UNIVAC was completed.
1947
William Shockley, John Bardeen, and Walter Brattain invent the transfer resistance device, better known later on as the transistor.
1948
Work on stored program computers continues at various locations in the U.S. and England. The first working prototype of a stored program computer is "Baby," at the Royal Society Computing Laboratory in Manchester.
T.J. Watson, Sr. orders the development of the Selective Sequence Control Computer (SSEC) for IBM, marking the beginning of IBMs movement away from card tabulating machines.
1949
The Electronic Delay Storage Automatic Computer (EDSAC), the first large-scale, fully functional stored program digital computer is built by Maurice Wilkes and his staff at the Mathematical Laboratory at Cambridge University.
1951
Jay Forrester and Bob Everett at MIT build a simulator for the Air Force, the Whirlwind. This is the first real-time processing computer, and the first to implement core memory.
The first UNIVAC is delivered to the Census Bureau.
Maurice Wilkes, Stanley Gill, and David Wheeler develop the concept of using subroutines to create reusable code modules. They write the first software development textbook, "The Preparation of Programs for an Electronic Digital Computer."
The Mark III computer is delivered to the Naval Surface Weapons Center, and is the first computer featured on the cover of Time Magazine.
1952
Grace Hopper, now working on UNIVAC at Remington-Rand, describes the basic concepts of the compiler and language translation.
After being featured on CBS News during election night coverage, UNIVAC becomes the household word for computer.
1953
IBM builds the IBM Type 701 EDPM, their first entry into the mainframe market that did not rely on punch card technology.
1954
IBM builds the IBM Type 650 EDPM, which still used the punch card technology (providing an upgrade path to early adopters), but was the first mass produced computer. Much to their surprise, IBM quickly leased over 1000 of them.
John Backus proposes the development of a high level language easily expressed in mathematical formulae, later known as the Formula Translator (FORTRAN).
1955
IBM introduces the 704, the first commercial machine with floating point hardware. The 704 is capable of a speed of 5000 operations per seconds, or 5 kFLOPS. It was designed by Gene Amdahl, who later worked on designing supercomputers in the 1990s.
The first computer user groups emerge: SHARE (originally not an acronym, but later defined as Society to Help Alleviate Redundant Effort) for IBM users, and USE for UNIVAC users.
1956
John McCarthy and Marvin Minsky organize a conference at Dartmouth to explore the concept of Artificial Intelligence (AI).
1957
IBM develops the IBM 305 RAMAC, the first computer using a disk memory system.
John Backus and his team deliver the first FORTAN compiler for the IBM 704. This was shortly followed by the first compiler error (a missing comma in a GOTO statement).
1958
Jack St. Clair Kilby demonstrates his idea of integrating transistors with resistors and capacitors on a single integrated chip.
The Whirlwind project culminates in the deployment of the SAGE system for the Air Force. The first air traffic control system also goes on-line.
Control Data Corporation markets the first fully transistorized computer, the CDC 1604, designed by Seymour Cray.
Continuing his work in AI, John McCarthy lays down the concepts for an AI programming language he calls LISP (LISt Processing), although later computer students prefer the acronym LISP (Lots of Idiotic, Silly Parentheses).
1959
IBM creates two separate product lines, the IBM 1401 for business and the IBM 1620 for scientists and universities.
General Electric Corporation delivers 32 ERMA (Electronic Recording Machine – Accounting) devices to the Bank of America for use in check processing. These were the first machines to make use of Magnetic Ink Character Recognition (MICR), leading to the automation of the banking system.
The TX-0, one of the first transistor-based computers, is placed on permanent loan to the Research Laboratory of Electronics (RLE) at MIT. The availability of the TX-0 inspires the first generation of MIT hackers.
1960
The first standardized business programming language, the Common Basic Oriented Language (COBOL) is created by an industry-wide team, based on previous work done by Grace Hopper. The second mathematical language, ALGOL 60, is also created by committee.
1961
The first commercial integrated chips are marketed by Fairchild Corporation.
Fernando Corbato of MIT produces the Compatible Time Sharing System (CTSS) operating system for the IBM 7090/94, the first time sharing operating system, and also the first system that allowed remote connection to a computer since the Stibitz demonstration in 1940.
Digital Equipment Corporation donates the first minicomputer, the PDP-1, to the RLE at MIT. The MIT hackers immediately begin working with it much as they had the TX-0.
Steve (Slug) Russell, one of the MIT hackers, creates Spacewar on the PDP-1, one of the first computer games.
1962
The Atlas computer at the University of Manchester goes operational. It features virtual memory and paging, pipelined instruction execution, and separate fixed and floating point arithmetic units. It achieves a speed of 200 kFLOPS.
1963
The first standardized data format is developed, the American Standard Code for Information Interchange (ASCII).
1964
Douglas Engelbart, working at the SRI Augmentation Research Center, continues research on human-computer interface using the On Line System (NLS). Among other areas, Engelbart and SRI developed the mouse, the concept of windows, hypertext, video conferencing, uniform command syntax, and structured file systems.
IBM delivers the first on-line, real time reservation system for American Airlines, called SABRE.
IBM introduces the IBM/360 family of computers. This is the first time the concept of a common operating system and upward compatibility is addressed.
The Dartmouth Time Sharing System becomes operational. It uses a language developed for student program development called BASIC.
1965
Digital Equipment Corporation introduces the first minicomputer, the PDP-8.
The CTSS at MIT gains the notice of J.C.R. Licklider, director of the Advanced Research Projects Agency (ARPA), who arranges Project MAC, consisting of teams from MIT, GE and Bell Telephone Laboratories to build a general purpose, time sharing, multiprocessing system called MULTICS.
1967
The first computer systems using integrated chip technology become available.
The NSF Pierce Report examines the state of computer education in U.S. colleges, and starts the development of formal computer curricula.
1968
Edsger Dijkstra writes a letter to the Association of Computing Machinery (ACM) entitled, "GOTO Statement Considered Harmful," igniting the debate on reliable software development.
Arthur C. Clarke introduces HAL in the movie "2001: A Space Odyssey." HAL is based on AI concepts developed by I.J. Good of Bletchley Park.
1969
Work on the ARPAnet begins.
Disillusioned by problems with MULTICS, Bell Telephone Laboratories withdraws from Project MAC. Two Bell employees, Ritchie and Thompson, begin work on their own operating system aimed at single users rather than multiple users. In a play on the name MULTICS, they name their system UNIX.
1971
Intel Corporation builds the first microprocessor, the Intel 4004.
Alan Shugart at IBM develops the first 8" magnetic floppy disk.
1972
The first digital microcomputer available for personal use is developed, the Micro Instrumentation and Telemetry System (MITS) 816. It does not have either a display or a keyboard.
ARPAnet is demonstrated at an ACM conference.
1973
Don Knuth delivers the first three volumes of what he envisions as a dozen volumes on "The Art of Programming." His work forms the basis of modern data structures, algorithms and programming techniques, and these three volumes are quickly hailed as the bibles of software development.
Robert Metcalfe develops Ethernet at Xerox Parc.
The U.S. District Court in Minneapolis invalidates the patent for the computer issued to Mauchly and Eckert, ruling that Mauchly had derived his ideas for the computer from John Vincent Atanasoff and the ABC. Neither Mauchly nor Eckert ever stopped opposing this verdict, insisting their invention was original.
Community Memory, an experiment in bringing public computer terminals to the masses, launches in Berkeley. The project lasts about two years, before dying from lack of funding.
1974
The March 1974 issue of QST Magazine contains the first ad for a personal computer, the Scelbi (SCientific, ELectronic, and BIological).
Jonathon Titus produces a widely available personal computer kit, the Mark 8.
Intel produces the 8080 microprocessor for the purpose of controlling traffic lights.
Gary Kildall introduces the CP/M operating system.
1975
The first mass produced personal computer marketed to customers other than electrical engineers appears, the MITS Altair 8800 (named after a planet on an episode of Star Trek), which used an Intel 8080 microprocessor running at 2 MHz. The Altair had 256 bytes of memory, no keyboard, no display, no secondary storage, and cost $375. As the Altair is featured in the cover story of the January issue of Popular Electronics, demand for the Altair immediately takes off, even though no machines had actually been built at that point. Bill Gates and Paul Allen later write their first product for the Altair, a BASIC compiler.
IBM introduces its first personal computer, the 5100. Due to the high price of both hardware and software, it does not catch on with the Altair crowd.
The Homebrew Computer Club, the first of the computer user groups for the general public, holds its first meeting in March.
William Crowther writes the first text based game, Adventure (also known as Colossal Cave).
CDC builds the first modern supercomputer, the Cray I, designed by Seymour Cray.
1976
Steve Jobs and Steve Wozniak release the Apple II, a completely assembled computer that came with a keyboard, display, and is affordable enough for the enthusiast. It is an immediate success, and is adopted throughout educational systems for use in fledgling computer courses.
Apple and Microsoft Corporations are both founded.
1977
Commodore introduces the Commodore PET, and Radio Shack releases the TRS-80 (affectionately known as the "Trash-80".
The first Computershack opens in Morristown, N.J.
1978
Daniel Bricklin and Bob Frankston release Visicalc, a spreadsheet program that set the standard for both the look and feel as well as the ease of use of future application programs.
1979
Micropro International releases Wordstar, which sets the standard for word processing programs. The business community begins to realize personal computers can be used for work, and are not the exclusive realm of the hobbyist.
1980
Alan Shugart uses his own company, Shugart Associates, to introduce the Winchester hard drive, bringing mainframe style storage into the realm of the personal computer.
1981
IBM releases the IBM PC, supported by the Microsoft DOS operating system and the Intel 8086/8088 chips, working at an initial clock speed of 5 MHz. IBM successfully markets the PC to users who see it as a tool for getting work done, rather than hobbyists who want to tinker.
Osborne Computer Corporation markets the first portable computer, the Osborne 1.
Commodore introduces the VIC-20 for the computer hobbyist community, and quickly sells over 1 million units.
1982
Intel releases the 80286, the first processor backwards compatible with software written for the previous Intel architecture. The 80286 clock speeds ran from 6 MHz to 12.5 MHz.
Time Magazine names the computer as Time's Man of the Year, the only time the title was awarded to an inanimate object.
Disney Studios releases the first movie that makes extensive use of computer special effects, Tron.
1983
Application programs and computer games proliferate. Mitch Kapor releases Lotus 1-2-3, which supplants Visicalc as the spreadsheet of choice.
After five years of development, the U.S. Department of Defense announces its new programming language, named Ada in honor of Ada, Countess of Lovelace. The Ada language introduced many new innovations, but was widely criticized for its complexity.
1984
In the famous Orwell inspired commercial, Apple Computer announces the Macintosh. According to Steve Jobs, the Macintosh was the result of his having viewed the Alto system at Xerox Parc. The mouse and icon soon become familiar tools for computer interaction.
1985
Government agencies and universities become aware that computer users, most of them young, are deliberately breaking into computer systems. The press comes to label these intruders as "hackers."
1986
Intel releases the 386 processor. The 386 featured a 32 bit chip, and ran at speeds of 16 MHz to 33 MHz.
The Cray X-MP is released. This is the first multiprocessing supercomputer, using four processors, and achieves a processing speed of 713 MFLOPS.
1989
Intel releases the 486 processor. The 486 was the first processor with a built-in math coprocessor, and ran at speeds of 25 to 50 MHz.
1993
Intel releases the Pentium processor. Clock speeds were 60 and 66 MHz.
1995
Intel releases the Pentium Pro processor, designed primarily for server and workstation applications. Clock speeds were 150 to 200 MHz.
1997
Intel releases the Pentium II processor. Clock speeds were 200 to 300 MHz.
1999
Intel releases the Celeron processor for the lower end consumer market. The Celeron runs around 300 MHz. The Pentium III is released for the higher end of the market, and runs between 500 and 650 MHz.
2000
Intel releases the Pentium 4 processor. It's initial clock speed is 1.5 GHz.
2002
Clock speed for the Pentium 4 is 2.2 GHz.
2003
Clock speed for the Pentium 4 is 3.06 GHz.
References:
Intel Corporation: www.intel.com
IEEE Computer Society: www.computer.org
Englander, Irv. The Architecture of Computer Hardware and Systems Software, 2nd Ed. John Wiley & Sons, 2000.
Encyclopaedia Britannica, 2005.