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 character (computing), characters and control characters with unique numbers. Typically each number represents the binary value in a s ...

s for the

Cyrillic script The Cyrillic script ( ) is a writing system used for various languages across Eurasia. It is the designated national script in various Slavic languages, Slavic, Turkic languages, Turkic, Mongolic languages, Mongolic, Uralic languages, Uralic, C ...

. The name stands for ''Kod obmena informatsiey'' () 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 communication. 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 represented as ...

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 data structure, array that replaces runtime (program lifecycle phase), runtime computation of a mathematical function (mathematics), function with a simpler array indexing operation, in a proc ...

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 p ...

. These encodings are derived from

ASCII ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable character, printable and 33 control character, control c ...

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 before ASCII. Each Chara ...

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 KOI-7 (КОИ-7) is a 7-bit character encoding, designed to cover Russian, which uses the Cyrillic alphabet. In Russian, KOI-7 stands for ''Kod Obmena Informatsiey, 7 bit'' (Код Обмена Информацией, 7 бит) which means "Co ...

(''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 the peso sign, is a currency symbol consisting of a Letter case, capital crossed with one or two vertical strokes ( or depending on typeface), used to indicate the unit of various currency, currencies around ...

$ (code point 24_hex) may be replaced by the

universal currency sign The currency sign is a character used to denote an unspecified currency. It can be described as a circle the size of a lowercase character with four short radiating arms at 45° (NE), 135° (SE), 225° (SW) and 315° (NW). It is raised slightl ...

¤).

KOI-8

KOI-8 (КОИ-8), standardized in 1974 as

GOST GOST () refers to a set of international technical standards maintained by the Euro-Asian Council for Standardization, Metrology and Certification (EASC), a regional standards organization operating under the auspices of the Commonwealth of I ...

19768, is an 8-bit extension 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 the ...

(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 the Russian subset of a Cyrillic script. KOI-8, on its turn, is an 8-bit exten ...

/ KOI8-RUSSIA for

Russian Russian(s) may refer to: *Russians (), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries *A citizen of Russia *Russian language, the most widely spoken of the Slavic languages *''The Russians'', a b ...

and Bulgarian (RFC 1489). (Code page 878) *

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 for Ukrainian (RFC 2319). (Code page 1168) *

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 ...

for Ukrainian, Belorussian and

. (Code page 1167) * KOI8-T for

Tajik Tajik, Tajikistan or Tajikistani may refer to. Someone or something related to Tajikistan: Tajik * Tajiks, an ethnic group in Tajikistan, Afghanistan and Uzbekistan * Tajik language, the official language of Tajikistan * Tajik alphabet, Alphabet u ...

. (FreeDOS Code page 62318) * KOI8-C, also KOI8-CA, a proposal for

Caucasus The Caucasus () or Caucasia (), is a region spanning Eastern Europe and Western Asia. It is situated between the Black Sea and the Caspian Sea, comprising parts of Southern Russia, Georgia, Armenia, and Azerbaijan. The Caucasus Mountains, i ...

and

Central Asia Central Asia is a region of Asia consisting of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The countries as a group are also colloquially referred to as the "-stans" as all have names ending with the Persian language, Pers ...

; hardly ever been used. (FreeDOS Code page 61294) *

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 t ...

KOI8-E 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 ...

(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. (FreeDOS Code page 60270) * KOI8-K1 "Cyrillic-1" (defined in CSN 36 9103, ST SEV 358–88) * KOI8-O (formerly KOI8-C) for Old Russian orthography. (FreeDOS Code page 63342) 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 885 ...

, and "KOI-8 N1" and "KOI-8 N2" which are variants of

Code page 866 Code page 866 ( CCSID 866) (CP 866, "DOS Cyrillic Russian") is a code page used under DOS and OS/2 in Russia to write Cyrillic script. It is based on the "alternative code page" () developed in 1984 in IHNA AS USSR and published in 1986 by a res ...

. 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 si ...

-based encoding used in

ES EVM The ES EVM (, "Unified System of Electronic Computing Machines"), or YeS EVM, also known in English literature as the Unified System or Ryad (, "Series"), is a series of mainframe computers generally compatible with IBM's System/360 and System/ ...

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 *Czech (surnam ...

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

Comecon The Council for Mutual Economic Assistance, often abbreviated as Comecon ( ) or CMEA, 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 states, Easter ...

. 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 ''diacrit ...

, 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. I ...

(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