ISO/IEC 6937

From Wikipedia, the free encyclopedia

ISO/IEC 6937 is a multibyte extension of ASCII, or rather of ISO/IEC 646-IRV, developed in common with ITU-T (then CCITT) for telematic services under the name of T.51. Certain byte codes are used as lead bytes for letters with diacritics (accents). The value of the lead byte often indicates which diacritic that the letter has, and the follow byte then has the ASCII-value for the letter that the diacritic is on. Only certain combinations of lead byte and follow byte are allowed, and there are some exceptions to the lead byte interpretation for some follow bytes. Note, however, that no combining characters at all are encoded in ISO/IEC 6937. But one can represent some free-standing diacritics, often by letting the follow byte have the code for ASCII space.

ISO/IEC 6937's architects were Hugh McGregor Ross, Peter Fenwick, Bernard Marti and Luek Zeckendorf.

ISO6937/2 defines 327 characters found in modern European languages using the Latin alphabet. Unfortunately non-Latin European characters, such as Cyrillic and Greek are not included in the standard. Also, some accents used with the Latin alphabet like the Romanian comma are not included.

The ISO/IEC 2022 escape sequence to specify the right-hand side of the ISO/IEC 6937 character set is ESC - R (hex 1B 2D 52).^[1]

Contents 1 Single byte characters 2 Two byte characters 3 Codepage layout 4 References

[edit] Single byte characters

The primary set of ISO6937/2 is based on ISO646 (characters 0x00..0x7f) with the exception of character 0x24 ($) which is denoted as a "general currency sign" (¤):

        !"#¤%&`()*+'-./0123456789:;<=>?@
        ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`
        abcdefghijklmnopqrstuvwxyz{|}

The supplementary set (characters 0x80..0xff) contains a selection of spacing and non-spacing graphic characters, additional symbols and some locations reserved for future standardisation.

[edit] Two byte characters

The characters which are not represented in the primary set are coded on two bytes. The first byte the "non spacing diacritical mark" is followed by a letter from the base set e.g.:

small e with acute accent (é) = [Acute]+e

In total 13 diacritical marks can be followed by the selected characters from the primary set:

Accent	Code	Second character	Result
Grave	0xC1	AEIOUaeiou	ÀÈÌÒÙàèìòù
Acute	0xC2	ACEILNORSUYZaceilnorsuyz	ÁĆÉÍĹŃÓŔŚÚÝŹáćéíĺńóŕśúýź
Circumflex	0xC3	ACEGHIJOSUWYaceghijosuwy	ÂĈÊĜĤÎĴÔŜÛŴŶâĉêĝĥîĵôŝûŵŷ
Tilde	0xC4	AINOUainou	ÃĨÑÕŨãĩñõũ
Macron	0xC5	AEIOUaeiou	ĀĒĪŌŪāēīōū
Breve	0xC6	AGUagu	ĂĞŬăğŭ
Dot	0xC7	CEGIZcegiz	ĊĖĠİŻċėġıż
Umlaut or diæresis	0xC8	AEIOUYaeiouy	ÄËÏÖÜŸäëïöüÿ
Ring	0xCA	AUau	ÅŮåů
Cedilla	0xCB	CGKLNRSTcgklnrst	ÇĢĶĻŅŖŞŢçģķļņŗşţ
DoubleAcute	0xCD	OUou	ŐŰőű
Ogonek	0xCE	AEIUaeiu	ĄĘĮŲąęįų
Caron	0xCF	CDELNRSTZcdelnrstz	ČĎĚĽŇŘŠŤŽčďěľňřšťž

[edit] Codepage layout

ISO/IEC 6937:1982[1]
	—0	—1	—2	—3	—4	—5	—6	—7	—8	—9	—A	—B	—C	—D	—E	—F
0−	NUL 0000 0	SOH 0001 1	STX 0002 2	ETX 0003 3	EOT 0004 4	ENQ 0005 5	ACK 0006 6	BEL 0007 7	BS 0008 8	HT 0009 9	LF 000A 10	VT 000B 11	FF 000C 12	CR 000D 13	SO 000E 14	SI 000F 15
1−	DLE 0010 16	DC1 0011 17	DC2 0012 18	DC3 0013 19	DC4 0014 20	NAK 0015 21	SYN 0016 22	ETB 0017 23	CAN 0018 24	EM 0019 25	SUB 001A 26	ESC 001B 27	FS 001C 28	GS 001D 29	RS 001E 30	US 001F 31
2−	SP 0020 32	! 0021 33	" 0022 34	# 0023 35	$ 0024 36	% 0025 37	& 0026 38	' 0027 39	( 0028 40	) 0029 41	* 002A 42	+ 002B 43	, 002C 44	- 002D 45	. 002E 46	/ 002F 47
3−	0 0030 48	1 0031 49	2 0032 50	3 0033 51	4 0034 52	5 0035 53	6 0036 54	7 0037 55	8 0038 56	9 0039 57	: 003A 58	; 003B 59	< 003C 60	= 003D 61	> 003E 62	? 003F 63
4−	@ 0040 64	A 0041 65	B 0042 66	C 0043 67	D 0044 68	E 0045 69	F 0046 70	G 0047 71	H 0048 72	I 0049 73	J 004A 74	K 004B 75	L 004C 76	M 004D 77	N 004E 78	O 004F 79
5−	P 0050 80	Q 0051 81	R 0052 82	S 0053 83	T 0054 84	U 0055 85	V 0056 86	W 0057 87	X 0058 88	Y 0059 89	Z 005A 90	[ 005B 91	\ 005C 92	] 005D 93	^ 005E 94	_ 005F 95
6−	` 0060 96	a 0061 97	b 0062 98	c 0063 99	d 0064 100	e 0065 101	f 0066 102	g 0067 103	h 0068 104	i 0069 105	j 006A 106	k 006B 107	l 006C 108	m 006D 109	n 006E 110	o 006F 111
7−	p 0070 112	q 0071 113	r 0072 114	s 0073 115	t 0074 116	u 0075 117	v 0076 118	w 0077 119	x 0078 120	y 0079 121	z 007A 122	{ 007B 123	| 007C 124	} 007D 125	~ 007E 126	DEL 007F 127
8−	128	129	130	131	132	133	134	135	136	137	138	139	140	141	142	143
9−	144	145	146	147	148	149	150	151	152	153	154	155	156	157	158	159
A−	NBSP 00A0 160	¡ 00A1 161	¢ 00A2 162	£ 00A3 163	164	¥ 00A5 165	166	§ 00A7 167	¤ 168	‘ 169	“ 170	« 171	← 172	↑ 173	→ 174	↓ 175
B−	° 176	± 177	² 178	³ 179	× 180	µ 181	¶ 182	· 183	÷ 184	’ 185	” 186	» 187	¼ 188	½ 189	¾ 190	¿ 191
C−	192	◌̀ 0300 193	◌́ 0301 194	◌̂ 0302 195	◌̃ 0303 196	◌̄ 0304 197	◌̆ 0306 198	◌̇ 0307 199	◌̈ 0308 200	201	◌̊ 030A 202	◌̧ 0327 203	204	◌̋ 030B 205	◌̨ 0328 206	◌̌ 030C 207
D−	― 2015 208	¹ 209	® 210	© 211	™ 212	♪ 266A 213	¬ 214	¦ 215	216	217	218	219	⅛ 215B 220	⅜ 215C 221	⅝ 215D 222	⅞ 215E 223
E−	Ω 2126 224	Æ 225	Đ 0110 226	ª 227	Ħ 0126 228	229	IJ 0132 230	Ŀ 013F 231	Ł 0141 232	Ø 233	Œ 234	º 235	Þ 236	Ŧ 0166 237	Ŋ 014A 238	ʼn 0149 239
F−	ĸ 0138 240	æ 241	đ 0111 242	ð 243	ħ 0127 244	ı 0131 245	ij 0133 246	ŀ 0140 247	ł 0142 248	ø 249	œ 250	ß 251	þ 252	ŧ 0167 253	ŋ 014B 254	SHY 00AD 255

Character code 0xA0 is a non-breaking space (U+00A0), while code 0xFF is a soft hyphen (U+00AD). The above table uses the Unicode combining accents (U+0300–U+036F) for the accents from codes 0xC1–0xCF, but the translation is not exact; Unicode combining accents suffix the accented character, while ISO/IEC 6937's non-spacing accents prefix the characters they modify.

[edit] References

1. ^ ^{a b} Supplementary Set of ISO/IEC 6937:1992 The high-ASCII half of the character set. (The left-hand side is U.S. ASCII.)