computer

Experimental model of the analytical engine Zuse Z3 , 1941 ENIAC , 1946 DEC PDP-7 , 1965 Apple II , 1977 IBM PC , 1981 Notebook ( laptop ) MacBook , 2006 IBM Blue Gene , 2007 Summit , 2018

A computer ( English ; German pronunciation [ kɔmˈpjuːtɐ ]) or calculator is a device that processes data using programmable arithmetic rules . Accordingly, the abstracting or outdated, synonymously used terms computer system , data processing system or electronic data processing system and electronic brain can also be found here and there.

Charles Babbage and Ada Lovelace apply by designed by Babbage 1837 Abacus Analytical Engine as a pioneer of modern universal programmable computer. Konrad Zuse ( Z3 , 1941 and Z4 , 1945) in Berlin, John Presper Eckert and John William Mauchly ( ENIAC , 1946) built the first functional devices of this type. When classifying a device as a universally programmable computer , Turing completeness plays an essential role Role. It is named after the English mathematician Alan Turing , who introduced the logical model of the Turing machine in 1936 .

The early computers were also called (main) computers; their input and output of data was initially limited to numbers. Modern computers know how to handle other data, for example letters and sounds. However, this data is converted into numbers within the computer and processed as such, which is why a computer is still a calculating machine today.

With increasing performance, new areas of application opened up. Today computers can be found in all areas of daily life, mostly in specialized variants that are tailored to a given application. Integrated microcomputers ( embedded system ) are used to control everyday devices such as washing machines and video recorders or to check coins in vending machines; In modern automobiles , for example, they are used to display driving data and control various maneuvers themselves in " driver assistants".

Universal computers can be found in smartphones and game consoles . Personal computers (English for personal computers, as opposed to the mainframe computers used by many) are used for information processing in business and authorities as well as for private individuals; Supercomputers are used to simulate complex processes, e.g. B. in climate research or for medical calculations.

Conceptual history

computer

The German term calculator is derived from the verb to calculate . For etymology see arithmetic # etymology .

computer

The English noun computer is derived from the English verb to compute . That is derived from the Latin verb computare , which means to add up.

The English term computer was originally a job title for assistants who carried out recurring calculations (e.g. for astronomy , for geodesy or for ballistics ) on behalf of mathematicians and thus made tables such as B. filled a log table. This profession was mainly carried out by women.

In the early history of the church , the Jewish calendar was replaced by the Julian calendar . The resulting difficulties in calculating the Easter date lasted until the Middle Ages and were the subject of numerous publications, often titled Computus Ecclesiasticus . But there are also other titles, e.g. B. by Sigismund Suevus 1574, who deal with arithmetic questions. The earliest text in which the word computer is used in isolation dates from 1613.

In the newspaper The New York Times , the word first appeared on May 2, 1892 in a small display of the United States Navy, entitled A Computer Wanted , wanted a computer ' on, in the knowledge of algebra , geometry , trigonometry have been provided and astronomy .

Ballistic tables were calculated on behalf of the United States Army at the University of Pennsylvania in Philadelphia. The result were books for the artillery that predicted the trajectories of different projectiles for different guns. Most of these calculations were done by hand. The only help was a tabulator that could multiply and divide. The employees who calculated there were called "computers" (in the sense of a human computer ). The term was first used in 1946 for a technical device in the Electronic Numerical Integrator and Computer (ENIAC) developed there . The term has been used in Germany since 1962.

Basics

There are basically two types of construction: A computer is a digital computer if it processes digital data (i.e. numbers and text characters) with digital device units; it is an analog computer if it processes analog data with analog device units (i.e. continuously running electrical measured variables such as voltage or current ).

Today digital computers are used almost exclusively. These follow common basic principles with which their free programming is made possible. A digital computer distinguishes between two basic components: the hardware , which is formed from the electronic, physically tangible parts of the computer, and the software , which describes the programming of the computer.

A digital computer consists initially only of hardware. First of all, the hardware provides a memory in which data can be stored in portions, like on the numbered pages of a book, and can be called up at any time for processing or output. Second, the arithmetic unit of the hardware has basic building blocks for free programming with which any processing logic for data can be represented: These building blocks are in principle the calculation , the comparison and the conditional jump . For example, a digital computer can add two numbers, compare the result with a third number, and then continue at either one or the other point in the program depending on the result. In computer science , this model is theoretically represented by the Turing machine mentioned at the beginning ; the Turing machine represents the fundamental considerations for predictability .

However, it is only through software that the digital computer becomes useful. In principle, every software is a defined, functional arrangement of the above-described components calculation, comparison and conditional jump, whereby the components can be used as often as required. This arrangement of the building blocks, known as a program , is stored in the form of data in the computer's memory. From there it can be read out and processed by the hardware. This principle of operation of digital computers has not changed much since its origins in the mid-20th century, although the details of the technology have improved considerably.

Analog computers work on a different principle. Analog components ( amplifiers , capacitors ) replace logic programming in them. In the past, analog computers were used more often to simulate control processes (see: Control technology ), but have now been almost completely replaced by digital computers . In a transition period there were also hybrid computers that combined an analog and a digital computer.

Possible uses for computers are:

Media design (image and word processing)
Management and archiving applications
Control of machines and processes (printer, industrial production using e.g. robots, embedded systems )
Calculations and simulations (e.g. BOINC )
Media playback (internet, television, videos, entertainment applications such as computer games, educational software)
Communication ( chat , email , social networks )
Software development

Hardware architecture

The principle generally used today, which, after its description by John von Neumann in 1946, is called the Von Neumann architecture , defines five main components for a computer:

the arithmetic unit (essentially the arithmetic-logical unit ( ALU )),
the control unit ,
the bus unit ,
the storage unit as well
the input / output unit (s).

In today's computers, the ALU and the control unit are usually merged into one component, the so-called CPU (Central Processing Unit, central processor ).

The memory is a number of numbered, addressable "cells"; each of them can hold a single piece of information. This information is stored in the memory cell as a binary number , i.e. a sequence of yes / no information in the sense of ones and zeros.

With regard to the storage unit, an essential design decision of the Von Neumann architecture is that the program and data share a memory area (the data usually occupy the lower memory area and the programs the upper memory area). In contrast, the Harvard architecture provides data and programs with their own (physically separate) memory areas. Access to the memory areas can be realized in parallel, which leads to speed advantages. For this reason, digital signal processors are often implemented in Harvard architecture. Furthermore, data write operations in the Harvard architecture cannot overwrite programs ( information security ).

In the Von Neumann architecture, the control unit is responsible for memory management in the form of read and write access.

The ALU has the task of combining values from memory cells. It receives the values from the control unit, calculates them (adds two numbers, for example) and returns the value to the control unit, which can then use the value for a comparison or write it to another memory cell.

Finally, the input / output units are responsible for entering the initial programs into the memory cells and displaying the results of the calculation to the user.

Software architecture

The Von Neumann architecture is, so to speak, the lowest level of the functional principle of a computer above the electrophysical processes in the conductor tracks. The first computers were actually programmed in such a way that the numbers of commands and of certain memory cells were written into the individual memory cells one after the other as the program required. Programming languages have been developed to reduce this effort . These automatically generate the numbers within the memory cells, which the computer ultimately processes as a program, from text commands that also represent semantically understandable content for the programmer (e.g. GOTO for the "unconditional jump").

Later certain repetitive procedures were combined in so-called libraries in order not to have to reinvent the wheel every time, e.g. E.g. interpreting a pressed keyboard key as the letter "A" and thus as the number "65" (in ASCII code). The libraries were bundled in higher-level libraries, which link sub-functions to complex operations (example: the display of a letter "A", consisting of 20 individual black and 50 individual white dots on the screen after the user has pressed the "A" key) .

In a modern computer, very many of these program levels work above or below one another. More complex tasks are broken down into subtasks that have already been processed by other programmers, which in turn build on the preparatory work of other programmers whose libraries they use. At the lowest level, however, there is always the so-called machine code - the sequence of numbers with which the computer is actually controlled.

Computer system

A computer system is called:

a network or a group of several computers that are individually controlled and can access shared data and devices;
the totality of external and internal components, ie hardware , software as well as connected peripheral devices , which requires a single fully functional computer in its interaction ;
a system of programs for controlling and monitoring computers.

story

species

Based on how the computer works

Based on the size

Smartphone
Personal Digital Assistant, or PDA, were the forerunners of smartphones.
Tablet computer
Embedded system , e.g. B. in the car, television, washing machine, etc.
Single board computer , e.g. B. Raspberry Pi , cheapest, very small computer. Mostly used as an embedded system.
Personal computer or PC, understood here as a desktop computer or workstation computer .
Host computer or server, integrated in a computer network, usually without its own display, keyboard, etc.
Thin clients are computers that only function properly in conjunction with a larger computer, usually a server.
Home computer (obsolete), the forerunner of the personal computer.
Game console
Smart TV
Netbook , a small notebook.
Laptop or notebook
Minicomputer (obsolete)
Super mini computer (obsolete)
Microcomputer (obsolete)
Mainframe computer or mainframe computer.
Supercomputers , the fastest computers of their time, need the space of a gym, the energy of a small town and are very expensive.

Future prospects

Even more important in less developed countries: a computer course in East Timor

Future developments are likely to consist of the possible use of biological systems ( biocomputers ), further links between biological and technical information processing, optical signal processing and new physical models ( quantum computers ).

A megatrend is currently (2017) the development of artificial intelligence . Here one simulates the processes in the human brain and creates self-learning computers that are no longer programmed as before, but are trained with data similar to a brain. The point in time when artificial intelligence outperforms human intelligence is called technological singularity . Artificial intelligence is already used today (2017) in many applications, including everyday ones (see Artificial Intelligence Applications ). Hans Moravec put the computing power of the brain at 100 teraflops , Raymond Kurzweil at 10,000 teraflops. Supercomputers have already significantly exceeded this computing power . For comparison, a graphics card for 800 euros (5/2016) has a performance of 10 teraflops. Four years later (December 2020) video game consoles already have comparable performance for around € 500.

For further developments and trends, many of which still have the character of buzzwords or hypes , see Autonomic Computing (= computer autonomy ), grid computing , cloud computing , pervasive computing , ubiquitous computing (= computer ubiquity) and wearable computing .

The worldwide web search for the term “computer” has been steadily decreasing since the statistics began in 2004. In the ten years to 2014, that number had fallen to a third.

Timeline

Worldwide market shares of computer manufacturers

Sales figures and market shares of the computer manufacturers according to the market research company Gartner Inc. , based on sales figures of desktop computers , notebooks , netbooks , but without tablet computers , to end consumers:

rank	Manufacturer	Sales figures 2017	Market share 2017	Sales figures 2011	Market share 2011	Sales figures 2010	Market share 2010	Sales figures 2009	Market share 2009
1.	Hewlett-Packard	55,179,000	21.0%	60,554,726	17.2%	62.741.274	17.9%	58,942,530	19.1%
2.	Lenovo	54,669,000	20.8%	45,703,863	13.0%	38.180.444	10.9%	24.735.404	8.0%
3.	Dell	39,793,000	15.1%	42,864,759	12.1%	42.119.272	12.0%	37,353,774	12.1%
4th	Apple	18,963,000	7.2%	under other	under other	under other	under other	under other	under other
5.	Asus	17,952,000	6.8%	20,768,465	5.9%	18,902,723	5.4%	under other	under other
6th	Acer group	17,087,000	6.5%	39,415,381	11.2%	48,758,542	13.9%	39,783,933	12.9%
	Toshiba	under other	under other	under other	under other	19,011,752	5.4%	15.499.805	5.0%
	Other manufacturers	59,034,000	22.5%	143,499,792	40.6%	128.862.141	34.5%	132.026.226	42.9%
	All in all	262,676,000	100%	352,806,984	100%	350.900.332	100%	308.341.673	100%

Well-known computer manufacturers

Current manufacturers

Taiwan Acer (with Gateway , Packard Bell , eMachines)
United States Apple
Taiwan ASRock
Taiwan Asus
Taiwan BenQ
Germany Blue chip computer
Taiwan Compal
United States Cray
United States Dell
Japan Fujitsu
Taiwan Gigabytes
China People's Republic Hasee
India HCL
United States HP Inc.
United States IBM
China People's Republic Lenovo
Canada MDG Computers
Germany Medion
Taiwan MSI
Japan NEC Corporation
Italy Olivetti
Japan Panasonic
Brazil Positivo
Taiwan Quanta computer
Russia Rover Computers
Korea South Samsung
Japan Sony
Japan Toshiba
United States Unisys
Turkey Vestel
United States ViewSonic
Germany Wortmann

Well-known former computer manufacturers

Acorn

Amdahl Corporation

Amstrad

Atari

Commodore International

Compaq

Control Data Corporation

Digital Equipment Corporation (DEC)

ELWRO

Diehl data systems

Dietz computer systems

Escom

Japan/ Fujitsu Siemens ComputersGermany
Austria Gericom
United States Kaypro
Germany Maxdata
United States Mohawk Data Siences Corporation (MDS)
United States NeXT
Norway Norsk Data
Germany Nixdorf computer
Germany Schneider Computer Division
United Kingdom Sinclair Research
Germany Waibel
Germany Zuse KG
Germany Robotron

literature

Konrad Zuse : The computer - my life's work . Springer, Berlin 1993, ISBN 3-540-56292-3 .
Ron White: This is how computers work. A visual foray through the computer & everything that goes with it . Markt + Technik, Munich 2004, ISBN 3-8272-6714-5 .

Story:

Edmund Callis Berkeley: Giant Brains or Machines That Think . 7th edition. John Wiley & Sons 1949, New York 1963 (the first popular representation of EDP, despite the title, which sounds strange to modern ears, very serious and well-founded - relatively easy to find antiquarian and in almost all libraries).
BV Bowden (Ed.): Faster Than Thought . Pitman, New York 1953 (reprint 1963, ISBN 0-273-31580-3 ) - an early popular representation of EDP, gives the status of its time understandably and in detail again; only to be found in antiquarian books and in libraries
Michael Friedewald: The computer as a tool and medium. The spiritual and technical roots of the personal computer . GNT-Verlag, 2000, ISBN 3-928186-47-7 .
Simon Head: The New Ruthless Economy. Work and Power in the Digital Age . Oxford UP 2005, ISBN 0-19-517983-8 (the use of the computer in the tradition of Taylorism ).
Ute Hoffmann: Computer women. What part did women have in computer history and work? Munich 1987, ISBN 3-924346-30-5
Loading history. Computer history (s) from Switzerland . Museum for Communication, Bern 2001, ISBN 3-0340-0540-7 , exhibition catalog for a special exhibition with a focus on Switzerland, but can be read on its own
HNF Heinz Nixdorf Forum Museum Guide . Paderborn 2000, ISBN 3-9805757-2-1 - Museum guide of the world's largest computer museum according to its own description
Karl Weinhart: Computer science and automation. Guide to the exhibitions . Deutsches Museum, Munich 1990, ISBN 3-924183-14-7 - Catalog for the permanent exhibitions of the Deutsches Museum on the subject; Especially recommended as supplementary literature for visiting the exhibition
HR Wieland: Computer history (s) - not just for geeks: From Antikythera to the cloud . Galileo Computing, 2010, ISBN 978-3-8362-1527-5
Christian Wurster: Computers. An illustrated story . Taschen, 2002, ISBN 3-8228-5729-7 (unfortunately the text is not very exact history of EDP with individual errors, but which has its value due to the guest contributions of individual personalities in computer history and the numerous photos).
Anfre Reifenrath: History of Simulation , Humboldt University, dissertation, Berlin 2000. History of the computer from its beginnings to the present with special consideration of the subject of visualization and simulation by the computer.
Claude E. Shannon: A Symbolic Analysis of Relay and Switching Circuits . In: Transactions of the American Institute of Electrical Engineers, Volume 57 . 1938 (pp. 713-723).