KOI (''КОИ'') is a family of several

code page In computing, a code page is a character encoding and as such it is a specific association of a set of printable characters and control characters with unique numbers. Typically each number represents the binary value in a single byte. (In some c ...

s for the

Cyrillic script The Cyrillic script ( ), Slavonic script or the Slavic script, is a writing system used for various languages across Eurasia. It is the designated national script in various Slavic, Turkic, Mongolic, Uralic, Caucasian and Iranic-speaking c ...

. The name stands for ''Kod obmena informatsiey'' (russian: Код обмена информацией) which means "Code for Information Interchange". A particular feature of the KOI code pages is that the text remains human-readable when the leftmost

bit The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...

is stripped, should it inadvertently pass through equipment or software that can only deal with 7 bit wide characters. This is due to characters being placed in a special order (128 codepoints apart from the Latin letter they sound most similar to), which, however, does not correspond to the alphabetic order in any language that is written in Cyrillic and necessitates the use of

lookup table In computer science, a lookup table (LUT) is an array that replaces runtime computation with a simpler array indexing operation. The process is termed as "direct addressing" and LUTs differ from hash tables in a way that, to retrieve a value v w ...

s to perform

sorting Sorting refers to ordering data in an increasing or decreasing manner according to some linear relationship among the data items. # ordering: arranging items in a sequence ordered by some criterion; # categorizing: grouping items with similar pro ...

. These encodings are derived from

ASCII ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because ...

on the base of some correspondence between Latin and Cyrillic (nearly phonetical), which was already used in Russian dialect of Morse code and in

MTK-2 The Baudot code is an early character encoding for telegraphy invented by Émile Baudot in the 1870s. It was the predecessor to the International Telegraph Alphabet No. 2 (ITA2), the most common teleprinter code in use until the advent of ASCII. ...

telegraph code. The first 26 characters from А (0xE1) in KOI8-R are А, Б, Ц, Д, Е, Ф, Г, Х, И, Й, К, Л, М, Н, О, П, Я, Р, С, Т, У, Ж, В, Ь, Ы, З.

KOI-7

The original KOI encoding (1967) was a 7-bit code page named KOI-7 (''КОИ-7''), which did not contain lowercase letters. In KOI-7, the codes of the 31 or 32 Russian letters are ordered according to the Latin letters. Other code points are the same as in

(however, the

dollar sign The dollar sign, also known as peso sign, is a symbol consisting of a capital " S" crossed with one or two vertical strokes ($ or ), used to indicate the unit of various currencies around the world, including most currencies denominated "p ...

$ (code point 24_hex) may be replaced by the universal currency sign ¤).

KOI-8

KOI-8 (КОИ-8), standardized in 1974 by GOST 19768, is an 8-bit extensions of ASCII. Originally it only included 32 lowercase and 31 uppercase Russian letters. Later derivatives of KOI-8 constitute the family of encodings variously known as KOI8, KOI 8 and KOI-8. The family members are: *

KOI8-B KOI8-B is the informal name for an 8-bit Roman / Cyrillic character set constituting the common subset of the major KOI-8 variants (KOI8-R, KOI8-U, KOI8-RU, KOI8-E, KOI8-F). Accordingly, it is closely related to KOI8-R, but defines only t ...

(with Ёё and Ъ) *

KOI8-R KOI8-R (RFC 1489) is an 8-bit character encoding, derived from the KOI-8 encoding by the programmer Andrei Chernov in 1993 and designed to cover Russian, which uses a Cyrillic alphabet. KOI8-R was based on Russian Morse code, which was creat ...

/ KOI8-RUSSIA for Russian and Bulgarian (RFC 1489). *

KOI8-U KOI8-U (RFC 2319) is an 8-bit character encoding, designed to cover Ukrainian, which uses a Cyrillic alphabet. It is based on KOI8-R, which covers Russian and Bulgarian, but replaces eight box drawing characters with four Ukrainian letters Ґ ...

KOI8-UKRAINE KOI8-U (RFC 2319) is an 8-bit character encoding, designed to cover Ukrainian, which uses a Cyrillic alphabet. It is based on KOI8-R, which covers Russian and Bulgarian, but replaces eight box drawing characters with four Ukrainian letters Ґ, � ...

for

Ukrainian Ukrainian may refer to: * Something of, from, or related to Ukraine * Something relating to Ukrainians, an East Slavic people from Eastern Europe * Something relating to demographics of Ukraine in terms of demography and population of Ukraine * So ...

(RFC 2319). *

KOI8-RU KOI8-RU is an 8-bit character encoding, designed to cover Russian, Ukrainian, and Belarusian which use a Cyrillic alphabet. It is closely related to KOI8-R, which covers Russian and Bulgarian, but replaces ten box drawing characters with five Ukra ...

for

, Belorussian and Russian. *

KOI8-T KOI8-T is an 8-bit single-byte extended ASCII character encoding adapting KOI8 to cover the Tajik Cyrillic alphabet. It was introduced by Michael Davis as an interim solution for representing Tajiki Cyrillic text in an interchangeable manner app ...

for Tajik. * KOI8-C, also KOI8-CA, a proposal for

Caucasus The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range, have historica ...

and

Central Asia Central Asia, also known as Middle Asia, is a region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes the fo ...

; hardly ever been used. *

ISO-IR-111 ISO-IR-111 or KOI8-E is an 8-bit character set. It is a multinational extension of KOI-8 for Belarusian, Macedonian, Serbian, and Ukrainian (except Ґґ which is added to KOI8-F). The name "ISO-IR-111" refers to its registration number in the I ...

/ KOI8-E (ECMA-113 (1st ed., 1986), multilingual for Slavic languages). *

KOI8-F KOI8-F or KOI8 Unified is an 8-bit character set. It was designed by Peter Cassetta of Fingertip Software (now defunct) as an attempt to support all the encoded letters from both KOI8-E (ISO-IR-111) and KOI8-RU (and hence also, KOI8-U and KOI8-R ...

, KOI-8 Unified. Includes the letter allocations from both KOI8-U and KOI8-E, with a subset of the pseudographics from KOI8-R. * KOI8-K1 "Cyrillic-1" (defined in CSN 36 9103, ST SEV 358-88) * KOI8-O (formerly KOI8-C) for Old Russian orthography. Additionally, GOST R 34.303-92 defines "KOI-8 V1" which is

ISO-IR-153 ISO-IR-153 (ST SEV 358-88) is an 8-bit character set that covers the Russian and Bulgarian alphabets. Unlike the KOI encodings, this encoding lists the Cyrillic letters in their correct traditional order. This has become the basis for ISO/IEC 8859 ...

, and "KOI-8 N1" and "KOI-8 N2" which are variants of Code page 866. ГОСТ Р 34.303-92
Наборы 8-битных кодированных символов. 8-битный код обмена и обработки информации.
= 8-bit coded character sets. 8-bit code for information interchange. These do not follow the KOI-8 layout.

DKOI

DKOI is an

EBCDIC Extended Binary Coded Decimal Interchange Code (EBCDIC; ) is an eight- bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems. It descended from the code used with punched cards and the corresponding ...

-based encoding used in

ES EVM The ES EVM (russian: Единая система электронных вычислительных машин (ЕС ЭВМ), translit=Yedinaya sistema electronnykh vytchislitel'nykh mashin (ES EVM), "Unified System of Electronic Computers"), o ...

mainframes. It has been defined by several standards: GOST 19768-74 / ST SEV 358-76, ST SEV 358-88 / GOST 19768-93, CSN 36 9103. There are two variants: *DKOI K1 (ДКОИ К1), each Cyrillic letter is given its own code point. *DKOI K2 (ДКОИ К2), some Cyrillic letters (А, В, Е, К, М, Н, О, Р, С, Т, Х, а, е, о, р, с, у, х) are merged with visually identical Latin letters.

Latin variants

Some encodings are called KOI, but define Latin alphabets: * KOI8-CS / KOI8-CS2 for

Czech Czech may refer to: * Anything from or related to the Czech Republic, a country in Europe ** Czech language ** Czechs, the people of the area ** Czech culture ** Czech cuisine * One of three mythical brothers, Lech, Czech, and Rus' Places * Czech, ...

and Slovak (ČSN (Czech technical standard) 369103, devised by the

Comecon The Council for Mutual Economic Assistance (, ; English abbreviation COMECON, CMEA, CEMA, or CAME) was an economic organization from 1949 to 1991 under the leadership of the Soviet Union that comprised the countries of the Eastern Bloc#List of s ...

. This encoded Latin with

diacritics A diacritic (also diacritical mark, diacritical point, diacritical sign, or accent) is a glyph added to a letter or to a basic glyph. The term derives from the Ancient Greek (, "distinguishing"), from (, "to distinguish"). The word ''diacriti ...

, as used in Czech and Slovak, rather than Cyrillic, but the basic idea was the same - text should remain legible with the 8-th bit cleared, thus e.g. Č became C etc.). *KOI8-L2 "Latin-2" (defined in CSN 36 9103), ISO IR 139ISO-IR-139
/ref> (almost identical to

ISO 8859-2 ISO/IEC 8859-2:1999, ''Information technology — 8-bit single-byte coded graphic character sets — Part 2: Latin alphabet No. 2'', is part of the ISO/IEC 8859 series of ASCII-based standard character encodings, first edition published in 1987. ...

(1987), but has the dollar sign and currency sign swapped) *DKOI CS2 (defined in CSN 36 9103) *DKOI L2 (defined in CSN 36 9103)

References

External links

* * * {{Character encoding Character sets