2. History

2.1 History of Computer Science

Since as long as we can remember, man has felt the need to record and to process data.

As society got more organized, this need grew steadily.

Writing was inverted so that precise records could be kept and transmitted to posterity.

Arithmetic flourished out of the need to manipulate figures and though calculations make out an important fraction of the computer applications we know today, this is only a fraction of the wide application fields, realized by the combination of human genius and technology.

In mankind, technology gets developed to assist man in dealing with repetitive tasks, with the technology available.
The invention of the art of printing and the application of purely mechanical means (presses, cast letters) illustrate how the technology of an era is applied to "process data" in the broadest sense. [art of printing: Gutenberg's Bible in 1450].

In the history of computing, arithmetic plays an important but ever decreasing role.

Since about 2000 B.C. the Chinese and the Egyptians manipulated the abacus; the "beans" on the different branches get different weights and their position indicate which should be taken into account.

Figure 2.1: abacus

Experienced abacus users succeed in fast calculations, however their speed is ultimately limited by the mechanical nature and the muscular ability of the operator; while the storage capacity is limited to 1 number (intermediate- or final result). The Mayans possessed it when the Spanish arrived.

In 1580, Francis Vieta invented the use of letters representing variables symbolically in mathematical formulas: an essential abstraction.

Follows the concept of "algorithm": a mathematical "recipe", describing step by step how to solve a mathematical problem.

In the 17th century, the first mechanical calculating devices were built after Napier's invention of the logarithms (1614), and his "bones" (marked ivory rods) for multiplication: the slide rules.
In 1623, Schickard a German astronomer built a wooden calculator, and in 1645 Pascal (the famous French mathematician) built an adding machine, relying on cog-wheels.
This adding machine allowed multiplications by repetitive additions.

During the same period, a new mathematical discipline: "Analytical Geometry" was developed by scholars like Descartes and Leibniz, who invented a mechanical calculator capable of multiplication.

The Renaissance brought several automata such as music boxes and barrel organs, where the "music" was kept in an "organ book" in the form of punched cards or a punched ribbon.

Typical for this generation of machines is the development of Jacquard's loom, a weaving machine capable of reading punched cards, containing the instructions for the patterns to be woven. Notice that the intellectual curiosity was ahead of the industrial realization at that time!

For the first time we see machines who's actions (the weaving of a pattern) are determined by one or more "programs" that are not an integrated part of the machine!

Remarkably, paper-tape (and punched cards) has been in use as the computer program and data storage medium by excellence until quite recently (the '70's).

About 1820, the Englishman Charles Babbage developed (with government aid) a "programmable" machine, capable to calculate mathematical and statistical tables: "The Difference Engine".

Figure 2.2: Difference Engine

The apparatus was programmed by punched cards and its main components bear remarkable resemblance to modern computers:

A larger prototype: "Analytical Engine", had to be driven by a steam engine however it was never completed.

About 1854, the Englishman George Boole developed a new mathematical logic: "Boole Algebra", the logic which almost all digital computers rely on.

Around 1890, a census had to take place in the United States, (according to the constitution, in order to determine the number of representatives from every state in the Congress). The growth of the population made this a technical-juridical problem: by hand the counting would take longer than the period determined in the constitution! How could this dilemma be solved?
Herman Hollerith, himself a US census employee, developed a census machine, relying on punched cards to treat population statistics, to tabulate and sort the results.
He founded a company: the "Tabulating Machine Company", later re-named CTR ("Computing-Tabulating-Recording"). He rented the machines but cleverly sold the patented cards. In 1924, the company was renamed again, to: IBM (International Business Machines).

detail view

After the first, purely mechanical data processing machines, we must be patient until around 1930 to find electrically driven (analog) calculators via projects at the M.I.T. (Massachusetts Institute of Technology) and in private companies (Burroughs).

About 1935, the British Alan Turing, elaborated a theory concerning automata. More precisely, he demonstrated a number of theorems about digital machines, driven by "tapes", the so called "Turing Machines". On a high theoretical level, Turing also demonstrated that some classes of problems cannot be solved, whatever the computing time devoted to find a solution!

"Digital machines" attribute discrete values to their variables, in contrast to "analog machines", where the variables can evolve in a continuous fashion (in a limited range of course).

Analog machines generally rely on currents or voltages that can be monitored with analog meters or plotters at given points in their circuitry.
Digital machines work with finite numbers and codes (so called discrete representations), which have a limited (however small the discrete steps are, compared to the full range) resolution.

In 1934, the German Konrad Zuse in Berlin, built the first mechanical digital programmable computer: the Z1. This machine was completed in 1937.
It worked with mechanical switches, a later version, the Z3 (in 1941), relied on electrical relays.

In 1939, George Stibitz in "Bell Laboratories", built the "Bell Model 1", a semi-automatic computer, mostly built with telephone relays. In that period, Atanasoff and Berry forwarded the idea to build a fully electronic machine.

Howard Aiken (Harvard University) completed the "Harvard Mark 1" in 1944. An electro-mechanical computer, built of +/- 750.000 parts, some 900 km of cable and with a memory realized with cog-wheels!
Instructions were given via paper tape, while data were entered via switches. To give an idea of the performance: the "Mark 1" performed an addition in .3 sec. and needed 6 seconds to multiply two numbers.
The machine was in use for 15 years!

In 1945 Dr. John von Neumann conceived the architecture for the digital computer: the so called "von Neumann architecture" currently still is by far the most used structure in the industry.

The first completely electronic "general-purpose" computer is completed in 1946 by Eckert and Mauchly at the Pennsylvania University: the "ENIAC" (for Electronic Numerical Integrator and Calculator).
Some 18.000 electronic valves enabled an addition in 0.2 milliseconds and a multiplication in 3 milliseconds. The tremendous heath development of ENIAC required a powerful cooling: in all ENIAC weight some 30 tons!

Figure 2.3: ENIAC

In 1947 the transistor was invented.

From this moment on, the electronic computer technology evolved fast: the realization of magnetic memory (small magnetic cores), the use of magnetic tape and the "drum" disks were realized in the early '50s.

In 1951, the first commercial computer hit the market: the UNIVAC I of which 48 were delivered.

Since the commercialization in the beginning of the '50s, the notion of "generations" was introduced as the technology evolved.

1st generation

The first generation (1950-1955) mainly relied on vacuum tubes. Programs were introduces with keys, directly into the memory locations; or via paper tape and/or punched cards. Programs and data were strictly separated.
To ease the use of machine instructions (binary codes), each instruction was given a meaningful name (mnemonic, like "SUB" for the subtraction instruction).
Translation of these symbolic instruction into machine instruction is called "assembling", it is performed by programs called "assembles" or "cross-assemblers", residing on other machines than the target-machine.
Assembler-programming is a dying art only performed rarely by specialists.

2nd generation

Applying transistors as basic building blocks, led to the second generation between ca. 1955 and 1965. Transistors made computers much more compact and reliable. In this period, the first "higher programming languages" were developed:

3rd generation

Between 1965 and 1970, the development of Silicon integrated circuits led to the third generation. The first "chips" (Small Scale Integration) were soldered to printed circuit boards. Via a photo-lithographic method, the cabling scheme could be multiplied efficiently and reliably.

n the '70s, the chip technology evolved from SSI to MSI (Medium Scale Integration) and later (~'76) LSI (large Scale Integration), even VLSI (Very Large Scale Integration).

4th generation

In the fourth computer generation, data storage is performed in semiconductor memory (about 1000 bytes or memory word elements per chip). Magnetic discs enable the storage of 1 to 10 million bytes.
The fourth generation also is characterized by the development of the "single chip" computer: the Intel 4004 or the Motorola 6800 were typical exponents, the first "systems" like the "Altair", were successful with hobbyists, as precursors of the IBM-PC, which hit the market in 1981.
Remarkable also is that the evolution is less and less marked by individuals, but ever more the result of group efforts emanating from universities, research institutes and companies.

Figure 2.4: PC
At the opposite end of the spectrum, "supercomputers" are designed, which finally start to enable scientists to manipulate realistic models of complex phenomena: the weather, astronomy, fluid dynamics, image processing and physiological processes in living tissue.


Figure 2.5: Supercomputer
During the 80's end-user applications come to maturity, as well as computer networking.

Both local area and world wide networks become operational, mostly thanks to the universities and the pioneering efforts into academic networking worldwide, soon followed by the commercial world.

In the last decennium (1985-1995), computers are applied in an ever widening spectrum of tasks: both "special purpose", targeted at a specific application as well as "general purpose", where users can adapt their applications to their needs, in the framework of a "operating system".

Programming steadily becomes an activity reserved to specialists and hobbyists, an ever decreasing fraction of computer users. Using and tailoring existing applications to one's needs is the concern of most people who want to benefit from computer technology.

Concerning the future, we can look at the main research directions, currently investigated:

Vinton Cerf: Pioneering internet architect

Tim Berners-Lee: inventor of the world wide web
The social impact of the computer as:

should not be underestimated.

As all human activities, the world of computers has its "subcultures", with tendencies, sometimes with almost fanatic proponents and opponents. Almost religious user groups have originated around applications and operating systems. They exchange experiences and information regarding the topic of interest and give rise to freely available programs, the so capped "Public Domain" software.
The worldwide computer network, the "Internet" is used both by the professional and by the amateur as the medium to exchange information and programs. The network is the medium for the existence of "virtual communities", a social development, never seen before!
One thing is certain: once we all get to do with computers in one way or another, therefore it is essential as an "educated" person at the end of the 20th century to get a good functional knowledge and some experience with adequate computers, in order to benefit as much as possible from this rich technology that came to existence by the contributions of countless human geniuses!

2.2 Overview

In following table, we condense the historical overview:

1580                Francis Vieta    letters as variables in formulas

1614                John Napier      logarithms as calculation tools

1637                René Descartes   Analytical Geometry

1642                Blaise Pascal    mechanical adding machine

1660                Isaac Newton     "Calculus"
                    Gottfried Leibniz loose from geometry

1805                Joseph Jacquard  automatic loom

1820                Charles Babbage  "Difference Engine"

1823                Charles Babbage  "Analytical Engine"

1853                George Boole     Boole algebra (binairy logic)

1890                Herman Hollerith automatic census tabulator

1921                Lee De Forest    vacuum tube as switch

1936                Alan Turing      theory of automata

1946                John Mauchly     first "digital" computer
                    John Eckert      ENIAC (at the M.I.T.)

1948                William Schockley invention of the transistor
                    John Bardeen     (Germanium)

1952                John von Neumann computer architecture

1957                1st computer languages

1965                interactive computer access

1981                development of the "personal computer" IBM-PC

1985                workstations, networks, supercomputers

1990                graphical interfaces

1992                multimedia, ...

1993                multi-processors, optical computers

1994                new architectures??
                    information highway, Internet commercial, Cyberspace ...

2000                the "millenium bug": from year 99 to 00!

2001                bursting of the "Internet bubble"

2003                this course: revised text.

2.3 From 1981 to 2003 under the spotlight:


August 12th: the first IBM-pc appears on the market for 3.000 dollar. The IBM-pc is based on the Intel 8088-processor with a clock-speed of 4,77 MHz, a 5,25-inch floppy disk with a capacity of 160 KB and 16 KB RAM-memory.
Microsoft introduces together with the IBM-pc the first version of the operating system MS DOS. The programming languages Basic, COBOL and Pascal hit the market for the IBM-pc.
The Hayes Smartmodem 300 is the first modem for the pc.


The spreadsheet program Lotus 1-2-3 (originally written by Mitch Kapor, later president of the "Electronic Frontier Foundation") appears on the market and becomes an instant success. Unfortunately, the IBM-pc is not capable to display the graphics on the screen. The venue of the Hercules Graphic-adapter, the ancestor of the "graphics cards", will enable this later on.
The pc's operating system is far from perfect. Peter Norton writes the "Norton Utilities", a selection of utility programs that make life easier with ms-dos.
Compaq introduces the Compaq Portable pc, a "portable" computer, 12 kilo's heavy, powered by an Intel 8088-processor. This portable is 3.000 dollar worth.


The Transmission Control Protocol and the Internet Protocol become known as the standard network protocol stack TCP/IP for the internet.
Microsoft expands its activities. Besides operating system and compiler development, they invest in application software: on September 29th, the first version of the text processor "word" is presented.
The first network operating system for the pc is developed by Novell: "Netware". Netware allows pc's in a network to share files with a server, facilitating greatly file sharing.
The second version of DOS, 2.0, is born on March 9th. Dos 2.0 supports the new 10-MB hard disks and 360-KB (5 inch) floppy disks.


On 14 August 14th, the development of PostScript starts, a language developed to describe the pages to be sent to a printer. Postscript files are hardware independent, they would be understood by any type of printer.
After the commercial failure of the Apple III and the Lisa, Apple launches a new model: the Macintosh. The Mac is based on the 68000-processor, has a graphical interface, with a mouse and is delivered with 128 KB of central memory. The monitor is black and white. Price tag: 2.500 dollar.
Hewlett-Packard launches the LaserJet, the first cheap laser printer for small office use. Cost price: about 3.500 dollar.
Intel launches the 80286-processor.


On November 20th, Microsoft launches Windows 1.0. Without great success, as very little application software is available
The battle between personal computer operating systems is mostly between DOS and CP/M. Currently, CP/M leads with 46 percent, followed by DOS with 31 percent. UNIX occupies a market fraction of 6 percent.
Toshiba commercializes the first laptop computer, the T1100. This computer is small, lightweight compared to the other "portable" computers, weighting 10kg on average. The T1100 becomes a world-wide success.
On March 15, the first commercial domain name is registered: Symbolics.com.


Next to the 5.25-inch floppy's - which are flexible, the 3.5-inch diskette appears on the market. This diskette is packaged in a hard (non flexible) plastic cover and has a metal clip. The new floppy's reliability is much higher.
Toshiba launches the first LCD-screen on the market. The screen has a 10 inch diagonal and can display eight colors. The resolution is 640 x 480 pixels.
The first SIMMs (Single Inline Memory Module) appear on the market. These make it very easy to extend the computer's central memory, which was soldered to the main board before.
In August 1986 Intel produces the 80386-processor.


Microsoft is rather active: in August DOS 3.3 is born and two months later,Windows 2.0 sees the daylight. More important however for end-users: on October 6th the appearance op Microsoft Excel for Windows, the first Windows spreadsheet.
The first computervirus, "Brain", starts infecting machines.
Microsoft and IBM collaborate since a few years to produce a new PC operating system: OS/2, of which version 1.0 is launched on April 2nd. Although Microsoft continues OS/2 development, they bluntly admit the have more confidence in their own product: Windows.
IBM introduces a new pc-line: PS/2. The models in this line have new features such as: VGA (Video Graphics Array) that will become a new standard. Model 50 en 60 are based on the 80286, but Model 70 is powered by the 80386-processor.


On November 2nd, Morris, one of the first Internet worms, contaminates 6.000 of the 60.000 Internet hosts. In a few hours time, the program that is capable of copying itself has propagated all over the USA.
IBM and Microsoft introduce OS/2 1.1. This operating system runs only on a pc with at least an 80286-processor, 4 MB central memory and requires at least 8 MB disk space.
In Augustus MS-DOS 4.0 appears on the market. This version has a graphical shell and supports "large hard disks with partitions up to 512 MB.


IBM launches the first commercial antivirusproduct on the market. Viruses are taken seriously and research for the optimal anti-virus strategy is started.
The Internet exceeds 100.000 hosts.
Compaq introduces the first non-interlaced monitor, producing the image at once on the screen. More stable to look at!
In August the Intel 80486-processor appears on the market. This processor has a mathematic co processor built in, important for spreadsheets and graphic applications.


On May 22nd, Windows 3.0 becomes available. This version shows files and disks as pictograms and fully exploits the capabilities of the 80386-processor.
Now that the Internet is at the eve of its commercial explosion, predecessor Arpanet is dissolved.
Computer viruses evolve fast. The latest sort is the polymorph virus, that can adapt itself, while propagating. Another virus type attacks different weaknesses of a system at once.
Not all computers are pc's and not all pc's are IBM-compatible. The market of the non-IBM-compatible computers is led by Apple, that occupies 15 percent of the market.
The first commercial Internet provider, giving access via dial-up lines is established. The World can be found on world.std.com.


Windows 3.11 appears. Four megabytes of RAM are required and 3.11 uses 6MB on the hard disk. Windows 3.11 will sell 50 million units, for a long timespan, the most popular version of Windows.
The World Wide Web (WWW) is developed at the "CERN", Europe's elementary particle research center near Geneva in Switzerland. Tim Berners-Lee is the main architect and developer of the Internet's "killer application".
Linus Torvalds writes the first programming lines of Linux. Contrasting with commercial operating systems, Linux is available free of cost as of 1992.
The CD-rom player gives multimedia characteristics (sound and video) to the computer.


The term "surf" is proposed by Gene Armour Polly.
Printers improve. The best printouts are generated by laser printers offering a resolution of 300 by 300 dots (dpi in the jargon). Hewlett-Packard improves on this by producing its latest LaserJet model, having a 600 x 600 dpi resolution.
First audio- and video-transmissions via the internet.


In March, Intel introduces a new generation of processors: the Pentium.
Pentium processors are available at clock speeds between 60 and 66 MHz. Unfortunately, pentium processors make errors in certain calculations. An arithmetic bug will be fixed later on.
On May 24th the first version of Windows NT is for sale. With this network oriented operating system, Microsoft wants to compete with Novell (Netware). Excel is integrated into Office and progressively bypasses Lotus 1-2-3.
The first version of the browser Mosaic is available. Marc Andreessen' program is the predecessor of the Netscape-browser and produces the breakthrough of the World Wide Web.
Novell gets to the market of application software and buys WordPerfect. Although WordPerfect has been a market leader in text processing for years, this packet looses the leadership. In 1996 WordPerfect will be sold again, this time to the Canadian company Corel, but by then, Word is the unchallenged market leader.
The White House becomes accessible via www.whitehouse.gov. Unfortunately, they forget to register the name, and are overtaken by an "adult entertainment" site!


Marc Andreessen and Jim Clark register Netscape Communications. The first beta version of their browser Netscape Navigator appears and is very successful with the first surfers.
In April, Commodore stops its activities. Commodore was one of the pioneering companies, together with Apple, Radio Shack (Tandy) and Sinclair who built "home computers" by the end of the 70's.
In November, the MPEG format appears, a compressed video format.


The cd-rom has become commonplace: worldwide 29 million cd-rom players are installed. Burning CD's on your own is not possible, until Hewlett-Packard launches the Surestore CD Writer 4020i on the market. Its price tag is still high but HP soon gets competition!
On August 24, the marketing campaign for Windows 95 starts off. In some instances, people even sleep in front of their stores to get to the software as soon as possible. In the first two months, Microsoft sells 7 million units.
The first Internet companies go public (on the stock market). One of the more visible ones is Netscape, in August.
The programming language Java appears (developed by Sun Microsystems). This platform independent language is considered as "the" solution for network-wide applications for the Internet. The ambition is to solve the problem of incompatibility between programs written for different platforms.


Toshiba demonstrates the first working Digital Versatile Disk system, better known as DVD.
In April, 3COM launches its first PalmPilot model, a Personal Digital Assistant or PDA.
This year, about 9,5 million computers are connected to the Internet.


The first TFT-screens for the desktop appear. These monitors have a high resolution, a completely flat screen and are completely free of distortion. Moreover, they consume only one third of the traditional CRT-monitors' energy.
Microsoft is dragged to court because it couples Internet Explorer to Windows 95. It will take years for the judge to sentence, but then Microsoft immediately went to appeal.
To process the media-streams faster, the pentium chips get an enriched instruction set, called MMX, in October the Pentium II appears.
Microsoft has a separate version of Windows for the very small computers - the PDAs - Windows CE. This year, version 2.0 comes out.


On June 25th, Windows 98 is in the stores. This new version is mainly targeted toward the consumer.
Compaq acquires Digital Equipment Corporation. A cost of 9,6 billion dollars.
The number of domain names breaks records: 2 million domain names are attributed.
HP produces its 30 millionth laserprinter.
IBM innovates. The Microdrive is the smallest hard disk in the world: (43x36x5mm), it can contain between 170 and 340 MB. The disk weights barely 20 grams.
Extensible Markup Language - XML - is introduced, to comprise multi-functional documents and data exchange via the web.
Larry Page and Sergey Brin have founded Google in 1998.


Intel produces new processors, among which the Celeron and the Pentium III. The competition however does not sleep: Advanced Micro Devices produces the Athlon.
Ricoh announces the first combined DVD-rom, cd-R (Recordable) and cd-RW (Rewritable) in one drive.


On February 17th, Windows 2000 appears, the long expected successor of Windows NT. Later in the year, a new "consumer" version of Windows appears: Windows Millennium Edition, or briefly Windows Me.
In October, Intel shows prototypes of the Pentium 4 in two versions, with a klockspeed of 1,4 and 1,5 GH (GigaHertz). A new step in the rave for ever faster processing chips.
America OnLine (AOL) buys mediagiant TimeWarner. The largest fusion ever (so far).
Originating from the Philippines, the "I Love You"-virus spreads over the planet. Millions of PC's are contaminated.
Bill Gates resigns as CEO of Microsoft on January 13th. His successor is Steve Ballmer. Gates remains president of the board and names himself "Chief Executive Architect".
Chip producer AMD starts producing Intels' "Celeron"'s competitor the "Duron".


Unbothered free exchange of music via the Internet comes to a halt as a judge concludes that Napster is at least partly responsible for the breaching of author rights via its service.
Napster starts filtering protected music.
The follower of the current generation Athlon processors gets the name: Athlon 4. Thereby overtaking Intel, that will only produce a mobile version of the Pentium 4 next year.
Apple launches its new operating system, Mac OS X, based on UNIX.
By the end of October, Windows XP is in the stores. Targeted to both the business user and the consumer.


The "Internet bubble" bursts: the whole telecom and ICT worlds are in crisis. Moreover, huge investments made by the telecom industry, lead to massive over capacity. As a consequence, the market crashes. Technological breakthrough of Linux: IBM chooses definitely for Linux on its complete range of systems.


At the beginning of 2003, there are about 500 million computers in the world!

Sources: "The Computer from Pascal to von Neumann" door Goldstine, "Computer Science" door Brookshear, "Computers and Computer Languages" door Silverman and Turkiew, Tijdnet, personal notes.