Computer

Basic principles: Accomplishment of the tasks set for it can provide the computer by means of movement of any mechanical parts, the movement of flows of electrons, photons, quantum particles or due to use of effects of any other well studied physical phenomena.

The greatest distribution among computers was gained by so-called "electronic computers", a computer. Actually, for the vast majority of people, the words "electronic computers" and "computers" became words — synonyms though actually it not so. The most widespread type of computers  — the electronic personal computer.

The architecture of computers can directly model the solved problem, is the closest (in sense of the mathematical description) reflecting the studied physical phenomena. So, electronic flows can be used as water threading models when modeling dams or dams. In this way the designed analog computers were normal in the sixties  the 20th century, however today became rather unusual occurrence.

In the majority of modern computers the problem at first is described in mathematical terms, at the same time all necessary information is provided in binary form (in the form of units and zero) then actions for its processing come down to application of simple algebra of logic. As practically all mathematics can be reduced to accomplishment of Boolean transactions, rather fast electronic computer can be applicable for the solution of the majority of mathematical tasks (as well as the majority of tasks of information processing which can be easily reduced to mathematical).

It was revealed that computers after all can solve not any mathematical problem. For the first time tasks which cannot be solved by means of computers were described by the English mathematician Alan Turing.

The result of the carried-out task can be provided to the user by means of different input/output devices of information, such as lamp indicators, monitors, printers, etc.

Beginning users and especially children often hardly perceive the idea that the computer  — just the machine and cannot independently "think" or "understand" those words which it shows. The computer only mechanically displays the lines and colors set by the program by means of input/output devices. The human brain itself recognizes in represented on the screen images, numbers or words and attaches them these or those significance.

Etymology

The word the computer is derivative of the English words to compute, computer which are translated as "calculate", "calculator" (the English word, in turn, comes from Latin computo — "I calculate"). Originally in English this word meant the person making arithmetic calculations with attraction or without attraction of mechanical devices. Further its value was postponed for machines, however modern computers carry out a set of the tasks which are not connected directly with mathematics.

For the first time the interpretation of a word the computer was published in 1897  in the Oxford English dictionary. His originators then understood the computer as the mechanical computing device. In 1946  the dictionary was replenished with the additions allowing to separate concepts of digital, analog and electronic computers.

History

Not computer

• 3000  years   — in Ancient Babylon were invented BC the first scores  — the abacus.
• 500  years  BC  — in China more "modern" version of the abacus with stones on a wire appeared.

Zero generation

• 87 year — in Greece were made BC "the antikitersky mechanism" — the mechanical device based on tooth gearings which is the specialized astronomical calculator.
•  1492  — Leonardo da Vinci provides the sketch of the 13-bit adder with ten-tooth rings in one of the diaries. Though the working device based on these drawings was constructed only in the 20th century, nevertheless the reality of the project of Leonardo da Vinci was confirmed.
•  1623  — Wilhelm Schikkard, professor of the university of Tuebingen, develops the device on the basis of cogwheels ("the considering hours") for addition and subtraction of six-bit decimal numbers. Whether the device was implemented during lifetime of the inventor, it is authentically unknown, but in 1960  it was recreated and proved quite operable.
• 1630   — Richard Delameyn creates a circular slide rule.
• 1642   — Blaise Pascal represents Paskalin  — the first mechanical digital computing device which is really performed and gained fame. The prototype of the device summed up and read five-unit decimal numbers. Pascal manufactured more than ten such calculators, and latest models operated with numbers with eight decimal positions.
• 1673   — the famous German philosopher and the mathematician Gottfried Wilhelm Leibniz constructed the mechanical calculator which by means of a binary numeral system executed multiplication, division, addition and subtraction.
• Approximately in the same time Isaac Newton lays the foundation of the mathematical analysis.
• 1723   — the German mathematician and the astronomer Christiaan Ludwig Gersten on the basis of Leibniz's works created the arithmetic machine. The machine calculated private and number of consecutive addition operations at multiplication of numbers. Besides, the possibility of control of correctness of data entry was provided in it.
• 1786  year  — the German military engineer Johann Müller puts forward the idea "differential machine"  — specialized calculator for tabulation logarithms, calculated by a differential method. The calculator constructed on step rollers Leibniz turned out rather small (13  cm in height and 30  cm c diameter), but at the same time could perform all four arithmetic operations over 14-bit numbers.
• 1801   — Joseph Mari Jacquard builds the software-controlled weaving loom which program of work is set using a set of punched cards.
• 1820  year  — the first industrial release arithmometers. The superiority belongs to the Frenchman Thomas de Calmarou.
• 1822   — the English mathematician Charles Babbage invented, but could not construct, the first differential machine (a specialized arithmometer for automatic creation of mathematical tables) (see. Differential machine of Charles Babbage).
• 1855   — brothers George and Edward Schutz (привет) of Stockholm constructed the first differential machine on the basis of Charles Babbage's works.
• 1876   — the Russian mathematician P.L. Chebyshev is created the summing-up device with continuous transfer of tens. In 1881 he designed to him a prefix for multiplication and division (Chebyshev's Arithmometer).
• 1884—1887   — Hollerith developed years electric the tabulating system which was used in population censuses USA (1890-m and 1900- m  years) and Russia century 1897.
• 1912   — the machine for integration of ordinary differential equations on the project of the Russian scientist A.N. Krylov is created.
• 1927   — in the Massachusetts Institute of Technology (MIT) was invented the analog computer.
• 1938   — the German engineer Conrad Tsuze soon after the termination in 1935  of the Berlin polytechnical institute constructed the first machine called Z1. (Also Helmut Shreyer ({ is mentioned as his coauthor { lang-de|Helmut Schreyer}})). It is completely mechanical programmable digital machine. The model was trial and in practical work was not used. Its recovered version is stored in the German technical museum in Berlin. The same year Tsuze started creation of the machine Z2.
• 1941  year  — Conrad Tsuze creates the first computer Z3, having all properties of the modern computer.
• 1942  year  — in Iowa State University (привет) John Atanasoff (привет) and it graduate student Clifford Berri (привет) was created (to be exact  — developed and began to mount) the first in USA electronic digital computer (привет). Though this machine was not complete (Atanasoff went to field army), it as historians write, had a great influence on Jonah Mochli, created two years after a computer Eniak.
• At the beginning of 1943  successful tests were passed by the first American computer Mark I intended for accomplishment of difficult ballistic calculations of the American VTR.
• At the end of 1943  the special purpose English computer started working the Colossus. The machine worked on interpretation of confidential codes of fascist Germany.
• In 1944  Conrad Tsuze developed faster Z4 computer.

Компьютер Eniak

• 1946  became year of establishment of the first universal electronic Eniak digital computer.

• In the Soviet Union the first electronic computer was created in Kiev by Lebedev's group in 1950 .
• In 1958 N.P. Brusentsov with group of supporters constructed the first ternary computer with a position symmetric ternary numeration system of "Xietun".

It is possible to learn about history of ADP equipment in more detail, having visited the Virtual museum.

Exponential development of the computer equipment

If to trace the history of development of computing devices, since 1900 , it is possible to notice characteristic doubling of performance for each 18 — 24  months. For the first time this feature in 1965  was described by the cofounder of Intel company Gordon E. Moore. (see Moore's Law). So promptly also process of miniaturization of computers develops. The first electronic computers (for example, such as  Eniak created in 1946) were the huge devices weighing many tons, occupying the whole rooms and requiring a large number of service staff for successful functioning. They were so expensive that only the governments and the big research organizations were able to afford them, and were represented so exotic that it seemed  — the small handful of such systems will be able to satisfy any future requirements. In contrast with it, modern computers  — much more powerful and compact and much less expensive  — became truly ubiquitous.

It is considered that exponential development of the computer equipment in the future can result in technology singularity.

Classification

Typification to destination

The most interesting achievements in the field of the computer equipment in the London Museum of Science

At the metro station in the city of Shenzhen the huge keyboard is installed. In waiting time of the train, you can sit on the ENTER keys, M, <L, P and ;).

• Calculator
• Console computer
• Minicomputer
• Mainframe
• Personal computer
  • Game console (Video game console)
  • Pocket computer (PDA)
  • the Dressed computer

• Workstation
  • Desktop computer
  • Notebook (Laptop)

• Server
• Supercomputer

On numeration systems

• binary
• ternary
• decimal

On an element basis

• relay
• lamp
• ferritdiodny
• transistor discrete
• transistor integral

The first ternary computer of "Xietun" on ferritdiodny cells was constructed by Brusentsov in MSU.

The superficial nature of the provided approach to classification of computers is obvious. It is usually used only for designation of common features of the most often found computer devices. Fast rates of development of ADP equipment mean permanent expansion of fields of its application and fast obsolescence of the used concepts. For more strict description of features of this or that computer usually it is required to use other schemes of classifications.

Physical implementation

More strict approach to classification is based on tracking of the computers of technologies used during creation. It is no secret that the earliest computers were completely mechanical systems. Nevertheless already in the thirties  the 20th  century the telecommunication industry offered developers new, electromechanical components (relay), and in the 40th the first completely electronic computers which had vacuum electron tubes in the basis were created. In the 50th  — the 60th  years lamps were succeeded by transistors, and in the late sixties  — the beginning of the 70th  years  — used and today semiconductor integrated circuits (silicon chips).

Point diodes on the basis of sulfide of lead (Pb) and oxide of tin (Sn) in detector radio receivers were one of the first semiconductors. Later semiconductors on a basis Germany (Ge) were developed. Still later semiconductors on the basis of silicon (Si) were developed. If to look at provision of these elements in the periodic table of D.I. Mendeleyev, then it is possible to notice that all of them are in one column and the movement happens up a column in Mendeleyev's table therefore it is possible to assume that the following semiconductors will be developed on the basis of carbon (the C Yayk of programming). On the planet Earth proteinaceous living beings in "dumatel" (brains) use proteinaceous educations (neurons) constructed of proteinaceous molecules which generally are long hydrocarbon molecules i.e. some proteins are semiconductors on the basis of carbon (the C Yayk of programming). Earth has the most perfect brain from proteinaceous beings on the planet the person.

The provided list technologies is not exhaustive; it describes only a top trend of development ADP equipment. During the different periods of history the possibility of creation computers on the basis of a great number of others, nowadays forgotten and time of very exotic technologies was investigated. For example, there were plans of creation of hydraulic and pneumatic computers, between 1903 and 1909  years somebody Percy I. Ludzhet even developed the project of the programmable analytical machine working based on sewing mechanisms (variables of this calculator were going to be defined by means of filar coils).

Now serious works on creation of the optical computers using light signals instead of traditional electricity are conducted. Other perspective direction means use of achievements of molecular biology and researches DNA. And, at last, one of the newest approaches capable to lead to grandiose changes in area of ADP equipment is based on development of quantum computers.

However, in most cases the technology of execution of the computer is much less important, than the design solutions put in its basis.

• Quantum computer and quantum communication
• Mechanical computer
• Optical computer
• Pneumatic computer
• Electronic computer
• Biological computer

File systems

Historically file systems became the first component of operating systems supporting work with disks, first their functionality was limited to distribution of disk space and preserving of names of the files appropriated by users.

The computer file is the most bottom level of abstraction of the data from physical storage existing in the form of bytes on the carrier. Today, speaking about files, most often mean files on disks, besides data in the form of files are stored also on flash cards, CD, DVD and on tapes of backup. On computers the concept "files" was used from fortieth years, so called a pack of punched cards.

On what the file was stored, it consists of data array and a folder – the container containing data with a unique identifier. In the annex to computer data the folder is called metadata, i.e. data on data. The term "disk file" (disk file) was for the first time used in documentation to the disk IBM 350 (1956), and "file system" (file system) in one of the first operating rooms with time sharing of Compatible Time-Sharing System (CTSS) developed in the Massachusetts Institute of Technology in 1961. On its basis OS Multics which in turn inspired creators of Unix was created.

In 1973 Harry Kildal developed the file system as a part of the CP/M OS for the 8-bit PC, it then changed it in DR-DOS of the 16-bit PC then as a result of a simple combination against the will of the author this file system found the new embodiment in the form of File Allocation Table (FAT) of Microsoft company.

In process of increase in the sizes of disks there were new file systems, Unix File System (UFS) became one of the major steps, it gave an impetus to development of the whole galaxy of file systems. Top became 128-bit file the Zettabyte File System (ZFS) systems, developed in Sun Micro Systems.

In recent years under the influence of need to work with Big Data development of file systems accelerated. They can be separated into two categories: distributed, usually set on clusters, and traditional, but expected work with big amounts of data. From the first the greatest fame was gained by Lustre, GPFS and two systems created "based on"

Lustre — GlusterFS and Ceph. The GPFS system is commercial, the others are available in open codes. The XtreemFS, MogileFS, pNFS, ParaScale, CAStor and Tahoe-LAFS systems are less popular. In the second category the undisputed leader – ZFS and LZJB close to it complemented with a shrinking algorithm of data without loss. Besides there are still NILFS developed in Nippon Telephone and Telegraph CyberSpace Laboratories and Veritas File System developed by Veritas Software company. Also the palliative solution where file systems from both groups are combined is not excluded.

In more detail about evolution of DWH read here.

Design features

Modern computers use all range of the design solutions developed for all the time of development of ADP equipment. These solutions, as a rule, do not depend on physical sale of computers, and are a basis on which developers rely. The most important issues resolved by creators of computers are included below:

Digital or analog

The fundamental solution at design of the computer is the choice whether it will be a digital or analog system. If digital computers work with discrete numerical or character variables, then analog are intended for processing of continuous flows of the arriving data. Today digital computers have much broader range of application though their analog fellows are still used for some special purposes. It is also necessary to mention that here also other approaches applied, for example, in pulse and quantum computings, however meanwhile are possible they are either highly specialized, or experimental solutions.

Examples of analog calculators, from simple to difficult, are: slide rule, astrolabe, oscillograph, TV, analog sound processor, auto pilot, brain.

Among the simplest discrete calculators the abacus, or ordinary scores is known; the most difficult of such systems is the supercomputer.

Binary, decimal or ternary

Example of the computer on the basis of decimal numeration is the first American computer Mark I.

Transition to internal representation of numbers in binary form became the major step in development of ADP equipment. It considerably simplified constructions of computing devices and peripheral equipment. Acceptance for a basis of a binary numeral system allowed to implement arithmetic functions and logical actions more just.

Nevertheless transition to to binary logic was not instant and unconditional process. Many designers tried to develop computers on the basis of more usual for the person decimal numeration. Also other constructive solutions were applied. So, one of early Soviet machines worked at a basis ternary numeration system which use is in many respects more profitable and it is convenient in comparison with binary system (the project ternary computer Xietun was developed and implemented by talented Soviet engineer N.P. Brusentsov).

The greatest memory storage density the numeration system with the basis equal to the basis of natural logarithms, i.e. equal to number e =2.71 has …. From integer numeration systems the ternary numeration system has the greatest memory storage density, binary and quaternary numeration systems share the second place. Therefore, at identical technology (number of inverters on 1 мм^2), ternary computers have considerably high capacity of RAM and big capacity of the processor. The ternary logic entirely includes binary logic as the central subset therefore ternary computers can do everything that can binary, plus possibilities of ternary logic. For example, transactions of multiplication and division on 3 and on 3^n in binary computers are executed by microprograms, and in ternary computers are executed hardware by one shift instruction on 1 or n of discharges to the right or to the left. Ternary algorithms work quicker than binary algorithms, but on binary computers this advantage is lost.

A bigger amount of memory and performance have computers with a nonintegral numeration system with the nonintegral basis equal to number e =2.71....

In general, however, the choice of an internal system of data view does not change the basic principles of operation of the computer — any computer can emulate any other.

Programmable

Capability of the machine to accomplishment of a certain changeable set of instructions (program) without the need for a physical reconfiguration is fundamental feature of computers. This feature gained further development when machines purchased capability dynamically to manage process of program execution. It allows computers to change independently an execution order of instructions of the program depending on a status of data.

Storing programs and data

At the runtime calculations often happens it is necessary to save intermediate data for their further use. Capacity of many computers substantially is defined by the speed with which they can read and write values in (from) memory and its general capacity. Originally computer memory was used only for storage of intermediate values, but it was soon offered to save the code of the program in the same memory (See the Von Neumann architecture), as data. This successful solution is used in the majority of computer systems today. However for managing controllers (a micro computer) more convenient was a scheme at which data and programs are stored in different sections of memory (Harvard architecture).

Classification by capabilities

One of the easiest ways to classify different types of computing devices determination of their capabilities is. All calculators can be carried to one of three types, thus:

• the specialized devices able to perform only one function (for example, the Antikitersky mechanism the 87th  year  BC or the filar predictor of William Thomson of 1876 );
• special purpose devices which can execute the limited range of functions (the first differential machine of Charles Babbage and various differential analyzers);
• the devices of general purpose used today. The name the computer is applied, as a rule, to machines of general purpose.

Modern general purpose computer

By consideration of modern computers the most important feature distinguishing them from early computing devices is what at corresponding programming any computer can imitate behavior any other (though this opportunity and is limited, for example, to the capacity of means of data storage or difference in speed). Thus, it is supposed that modern machines can emulate any computing device of the future which can be ever created. Somewhat this threshold capacity is useful to distinction general purpose computers and special purpose devices. Determination "general purpose computer" can be formalized in the requirement that the specific computer was capable to imitate behavior universal machine Turing. The machine Z3 created by the German engineer Conrad Tsuze in 1941  a year is considered the first computer meeting such condition (the proof of this fact was made c 1998).

Technologies of the future

See Also: Moore's law

IBM created the transistors similar to a human brain

In April, 2013 it became known that IBM found a method of production of transistors which, united in special schemes, can simulate work of a human brain completely.

New transistors will be manufactured of materials with strong correlation, such as metal oxides that will allow to make schemes more powerful, but less power-intensive, developers stated.

"Opportunities to scaling of standard transistors are almost exhausted after "race" of the last 50 years", -Stuart Parkin, the employee of IBM Research said. "Now we should consider alternative devices and materials which will work essentially in a different way", - he added.

Scientists try to find a method of change of conductivity of the correlating materials for the last several years. Parkin's team became the first which performed conversion of metal oxides from isolated in the carrying-out status using oxides of ions. The command published article about this method in the Science magazine recently.

Theoretically, such transistors will be able to imitate work of a human brain, and the computing power of such systems in comparison with traditional computers "on silicon" will be million times higher.

Work of Intel on "a computer brain"

In May, 2012 Intel in Israel began developments in the field of creation of "a computer brain": technology which will be capable to self-training. "Training of machines has huge perspectives" - said Justin Rattner, the technology director of Intel. "Despite the name, smartphones remain mute devices. My smartphone knows about me no more, than that day when I purchased it", - he added.

According to him, devices of new type will come into closer contact to the owners. Within the researches which will be conducted by Intel Collaborative Research Institute for Computational Intelligence jointly with specialists of Technion in Haifa and Hebrew University in Jerusalem, it is going to create new devices, portable computers with a specialized software.

Intel will perform developments of "computer intelligence" based on the new research center in Israel in which development is going to invest 15 million dollars in the next five years

For example, if the owner of the device constantly leaves keys at home, then the first week it will remember where he usually leaves them, and on the second week will begin to remind actively to take keys before leaving. Devices of this kind will become available in the market in 2014-2015, Ratner said.

Moody Eden, the president of Intel Israel, also noted: "Within five years all human feelings will be available to computers, and in 10 years of transistors on one chip will be more, than neurons in a human brain".

According to Ratner, Intel uses new technologies of this plan in developments for Adidas company. The new system of Adidas will define who buys footwear, the woman or the man, the adult or the child, and then to show models, suitable for the buyer.

Use of computers

The first computers were created only for calculations (that is reflected in the names "computer" and "computer"). Even the most primitive computers in this area many times over exceed people (except for some unique people counters). Not accidentally the Fortran intended only for accomplishment of calculations was the first high-level programming language.

Databases were the second large application. First of all they were necessary to the governments and banks. Databases require already more difficult computers with the developed input-output systems and information storages. The Kobol language was developed for these purposes. There were DBMS with own programming languages later.

The control of various devices was the third application. Here development went from highly specialized devices of standard computer systems, (often analog) to gradual implementation, on which managing programs are started. Besides, the increasing part of the equipment begins to include the managing computer.

At last, computers developed so that the computer became the main information tool as at office, and at home.  I.e. now almost any work with information is carried out via the computer  — whether it be text typing or watching movies. It belongs both to information storage, and to its transfer on communication channels.

The most difficult and underdeveloped use of computers is the artificial intelligence  — use of computers for the solution of such tasks where there is no accurately certain more or less simple algorithm. Examples of such tasks  are games, machine translation of the text, expert systems.

Mathematical models

• Von-Neumann's automatic machine
• Von-Neumann's machine
• Abstract state machine
• Finite state machine
• The finite state machine with memory
• Universal Turing machine
• Nanocomputer
• Quantum computer and quantum communication
• Edlman's biocomputer
• Final bioautomatic machine of Shapiro

Architecture of computers

• Von Neumann architecture
• Harvard architecture
• Bus architecture of the computer against channel architecture
• Architecture of the personal computer
• Classification of parallel computing systems

• Computer memory
• Processor

Links

• Setup and repair of the PC
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• technology of programming
• programming methodology
• Minicomputers