KOI8-R

KOI8-R is an 8-bit character encoding, designed to cover Russian, which uses the Cyrillic alphabet. It also happens to cover Bulgarian. A derivative encoding is KOI8-U, which adds Ukrainian characters. The original KOI-8 encoding was designed by Soviet authorities in 1974. KOI8 remains much more commonly used than ISO 8859-5, which never really caught on. Another common Cyrillic character encoding is Windows-1251. A way to represent Cyrillic together with other non-Latin languages is Unicode.

In Russian, KOI8 stands for "Kod Obmena Informatsiey, 8 bit" (Код Обмена Информацией, 8 бит) which means "Code for Information Exchange, 8 bit".

The KOI8 character sets have the property that the Russian Cyrillic letters are in pseudo-Roman order rather than the natural Cyrillic alphabetical order as in ISO 8859-5. Although this may seem unnatural, it has the useful property that if the 8th bit is stripped, the text is partially readable in ASCII and may convert to syntactically correct KOI7. For instance, "Русский Текст" in KOI8-R becomes "rUSSKIJ tEKST" ("Russian Text") if the 8th bit is stripped; attempting to interpret the ASCII string "rUSSKIJ tEKST" as KOI7 yields "Русский Текст".

Codepage layout

KOI8-R
	x0	x1	x2	x3	x4	x5	x6	x7	x8	x9	xA	xB	xC	xD	xE	xF
0x	"Control characters"
1x
2x	SP	!	"	#	$	%	&	'	(	)	*	+	,	-	.	/
3x	num|0	num|1	num|2	num|3	num|4	num|5	num|6	num|7	num|8	num|9	:	;	<	=	>	?
4x	@	A	B	C	D	E	F	G	H	I	J	K	L	M	N	O
5x	P	Q	R	S	T	U	V	W	X	Y	Z				^	_
6x	`	a	b	c	d	e	f	g	h	i	j	k	l	m	n	o
7x	p	q	r	s	t	u	v	w	x	y	z	{	|	}	~
8x	─	│	┌	┐	└	┘	├	┤	┬	┴	┼	▀	▄	█	▌	▐
9x	░	▒	▓	⌠	■	∙	√	≈	≤	≥	NBSP	⌡	°	²	·	÷
Ax	═	║	╒	ё	╓	╔	╕	╖	╗	╘	╙	╚	╛	╜	╝	╞
Bx	╟	╠	╡	Ё	╢	╣	╤	╥	╦	╧	╨	╩	╪	╫	╬	©
Cx	ю	а	б	ц	д	е	ф	г	х	и	й	к	л	м	н	о
Dx	п	я	р	с	т	у	ж	в	ь	ы	з	ш	э	щ	ч	ъ
Ex	Ю	А	Б	Ц	Д	Е	Ф	Г	Х	И	Й	К	Л	М	Н	О
Fx	П	Я	Р	С	Т	У	Ж	В	Ь	Ы	З	Ш	Э	Щ	Ч	Ъ

External links

* RFC 1489
* [http://koi8.pp.ru/ All about KOI8-R]
* [http://2cyr.com/decode/ Universal Cyrillic decoder] , an online program that may help recovering Cyrillic texts with broken KOI8-R or other character encodings.
* [http://czyborra.com/charsets/cyrillic.html A brief history of Cyrillic encodings]