English language encoding. Encoding symbols and texts

To encode characters, you need to select a certain code table. It defines the sets of valid characters and their associated whole codes.

There are 7-bit, 8-bit, 16 and 32-bit code tables.

ASCII (7 bit) 8-bit tables ...

Codes 0 ... 127 (0 ... 7F codes 128-255 (80..FF)

Identical and used for…. symbols of any

Match the language, i.e. there are many 8-bit

ASCII in all modern code tables. Often several for

Encodings. one language.

8 bit tables for the Russian language.

1) cf. 1251 (windows- 1251)

2) KOI 8- R (example: in Unix systems)

3) ISO - 866 (GOST - A, previously used in OC DOS).

The text is represented by a sequence of characters and the main difference is in the methods of encoding line hyphenation. In Windows, the time of symbols is 1310, in UNIX with a code of 10.

To eliminate the various code tables, a 16-bit UNOCODE table was introduced. Which today is the standard, recommended for use….

There is UNICODE 32 and UNICODE 62, which solve the problem of Asian languages.

D / Z .: 1) Take the day and month of birth in 4 values ​​of the number and write it down in binary, ternary, octal and hexadecimal systems. 2) Considering that this number is written in the hexadecimal system and write in the decimal system. 3) Encode the surname in cf. 1251, KOI 8-R and UNICODE.

Encodings based on code table UNICODE:

1. Encodings with a constant number of bits per character. (UCS 2 - 2 bytes per character (inside OC windows and in the parameters of its system calls - from windows 2000 (win NT 5.0))).

In programming languages ​​that have a data type for UNICODE characters.

2. Encodings with a variable number of bits per characters (UTF). In these encodings, a character from the range 0 ... 127 gives the minimum number of bytes, and the rest is increased. UTF- 8. Characters from the range 0 ... 827 are encoded in one byte, the rest in 2, 3, 4 or 5 bytes. The encoding was invented for compatibility with old software that works with single-byte strings. English text looks the same as in ASCII encodings, search and alphabetical ordering specifically works even for multibyte characters. Used on the Internet.

UTF-16 characters with a range of 0… .32267 are allocated with 2 bytes, the rest are more bytes. UTF-16 has the same relationship with UCS-2 as UTF is with ASCII.

At the beginning UNICODE- text sometimes 2 bytes of special purpose are added. They are called BOM-BITE ORDER MARK.

Forward and backward byte order.

The memory of any modern computer can be thought of as a long tape, consisting of individual bytes. Each byte has an address, starting with O and so on. Suppose, starting from a certain address, their byte integer is located in memory. It can be mixed in two ways: 1) first high byte, then the rest to low - big endian BE-Big Endean's.

2) First, the least significant byte, then the rest to the most significant - big endian "pointed" LE - Little Endean's.

Intel (AMD) architecture uses LE.

Color coding.

Any color on the screen is obtained from a combination of three basic ones: red, green, blue and yellow taken in different correspondence.

Standard software representation is 3 bytes per color, 1 byte for R, G and B components (RGB-form).

FFFFFF - white codes with the same value, OOOOOO - black bytes correspond to shades of gray.

Sometimes, in image plots, information about the transparency of a point is needed. Then the 4th byte of the transparency is added. It is called the alpha channel, and the RGBA format.

Other basic colors (CMYK) are used in printing.

Presentation: presentation of real numbers.

In technology, not only the binary system is used: the ternary balanced number system (each digit can take one of 3 values: 0.1; -1; dignity: significance - as informational (in mathematics it is proved that the best base is the most economical, and the closest) and engineering (we can use both later and a negative signal). It was first applied in a computer "step" by Brusentsov. It is convenient to represent negative numbers - it is not necessary additional code... Modular arithmetic: modularity coding is used. In such a representation, machine arithmetic for operations is more complicated and multiplication is performed an order of magnitude faster. (10 or more times).

D \ Z: Encode the last name in UTF-8.

Informatics and information Technology.

Computers were originally designed for computing. The branch consisted of the engineering practice of creating computers and special sections of mathematics - the theory of algorithms and computational mathematics. At the same time in 1946. Cybernetics appears. This is the name of the book by the American scientist NORBERT WINNER. The author defined cybernetics as the science of control in biological and theoretical systems. By this time, general systems theories already existed. (Textual criticism is a general organizational science by AA Bogdanov; “systems theory” by Bertolonfy). Wiener also deals with systems in a general sense, but focuses on control mechanisms and information processes, on their commonality in a variety of systems. There is an understanding of the generality of these processes and there are universal computers. A natural step is the idea of ​​using these machines for any information processing task. These ideas quickly spread to scientific environments in other countries. Artificial intelligence (AI) was the ultimate price point for cybernetics. The direction of AI gave a solution to many problems: pattern recognition, automatic control technology, natural language processing.

Under the auspices of cybernetics in different countries the automation of the economy began, that is, computers were used for data processing. In the USSR, the OGAS project began, which assumed the creation of a single network between all enterprises and the complete informatization of management with a reduction in bureaucracy (Luzhkov). For political reasons, the project was scaled down to separate automation systems (ACS). Under the influence of Luzhkov's idea, Stafford Beer created such a system in Chile for the Allende government. Since cybernetics has disintegrated into many practical and theoretical teachings, its name is mainly used historically. And since the 70s, the term "informatics" and "information technology" has spread.

Informatics is a field of science dealing with data processing problems.

What you can do with data: store, transform and transfer.

When the information system interacts with the outside world. They can be considered as transmission, but they are too special for collecting data and managing external objects.

Example of data collection: Using sensors in a plant control system. Control example: Automatically control machinery.

Information technology (IT.) - the use of those. means for solving problems of informatics.

Those. means - hardware and software systems.

In modern electronics, that is, at any level, therefore, any hardware system is actually software and hardware.

Software intended to work as part of a physical device is called probable software.

This table maps each character to a sequence of one or more bytes.

Although the term "character set" (eng. character set, charset), legalized by RFC 2278, is now perhaps the most authoritative, the term "encoding" that preceded it (eng. encoding) is still used synonymously, in particular in programming languages,, and.

Quite often, instead of the term "character set", the term "code page" is used incorrectly, meaning in fact a special case of a single-byte encoded character set.

Currently, three types of encodings are mainly used: EBCDIC compatible and Unicode-based 16-bit, with an overwhelming predominance of the former. The Unicode representation is ASCII compatible. DKOI-8 based encodings) are used only on some mainframes. Originally, each operating system used one character set. Now the character sets used depend on the type operating system only by tradition and are set according to the locale.

Automatic encoding recognition

The use of many encodings in modern software creates a lot of inconvenience not only for programmers, but also for users. According to one point of view, it is possible to cope with crocodiles if the programs will automatically recognize the encoding of the incoming text.

For single-byte encodings, you can take into account the fact that the frequency of using different letters varies greatly (for example, in Russian, "o" is often used, but rarely "b"). Therefore, knowing the language of the text, you can easily choose an encoding in which the byte frequency better matches the frequency of the letters of the given language.

An alternative point of view considers such heuristic algorithms for determining the encoding of a text to be harmful, since modern information technologies have the means to unambiguously match the code page assigned to the text (see, for example, programs for creating text data that violate standards.

Common encodings

Synonyms:

See what "Encoding" is in other dictionaries:

encoding- and, w. Action by value ch. encode. Information encoding for machine information processing. MAC 2 ... Historical Dictionary of Russian Gallicisms

CODE, rude, rue; anny; owls. and not sov. that (spec.). Ozhegov's Explanatory Dictionary. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 ... Ozhegov's Explanatory Dictionary

Noun, number of synonyms: 4 encryption (7) encryption (8) encryption (7) ... Synonym dictionary

J. decipher. 1. the process of action on nesov. ch. encode I, encode I 2. The result of such an action; coding I 2 .. Efremova's Explanatory Dictionary. T.F. Efremova. 2000 ... Modern explanatory dictionary of the Russian language by Efremova

encoding- see encode ... Explanatory translation dictionary

encoding- coding, and ... Russian spelling dictionary

encoding- ed. codirane, code, code table ... Български synonymous with river

encoding- see encode; and; f. Kodirovka / wka information for machine information processing ... Dictionary of many expressions

font encoding- (Encoding) An ordered set of characters in a font [an ordered set of characters in a specific writing system] (see Codepage). The encoding depends on the operating system for which the font is intended (MS Windows or Mac OS) and ... ... Font terminology

frame encoding- The sequence of fields in CAN frames, for example, for a data frame: SOF, arbitration field, check field, data field, CRC field, acknowledge field and EOF. The frame encoding also includes bit stuffing. , "es": ["gHfWy3fmx7g", "cg5D3fEhjnE"], "pt": ["q5VgJy_eL-U", null], "it": ["Aop4sMQwjoM"], "bg": ["2v0MInag9Ic"], " la ": [" W8crjqn-XMA "]," el ": [" VUy1dqner14 "])