Word codes of computer

Список из 256 символов и их коды в ASCII.

1

Управляющие символы

DEC	OCT	HEX	BIN	Символ	Escape послед.	HTML код	Описание
0	000	0x00	00000000	NUL		�	Нулевой байт
1	001	0x01	00000001	SOH			Начало заголовка
2	002	0x02	00000010	STX			Начало текста
3	003	0x03	00000011	ETX			Конец «текста»
4	004	0x04	00000100	EOT			конец передачи
5	005	0x05	00000101	ENQ			«Прошу подтверждения!»
6	006	0x06	00000110	ACK			«Подтверждаю!»
7	007	0x07	00000111	BEL	a		Звуковой сигнал – звонок
8	010	0x08	00001000	BS	b		Возврат на один символ (BACKSPACE)
9	011	0x09	00001001	TAB	t		Табуляция
10	012	0x0A	00001010	LF	n		Перевод строки
11	013	0x0B	00001011	VT	v		Вертикальная табуляция
12	014	0x0C	00001100	FF	f		Прогон страницы, новая страница
13	015	0x0D	00001101	CR	r		Возврат каретки
14	016	0x0E	00001110	SO			Переключиться на другую ленту (кодировку)
15	017	0x0F	00001111	SI			Переключиться на исходную ленту (кодировку)
16	020	0x10	00010000	DLE			Экранирование канала данных
17	021	0x11	00010001	DC1			1-й символ управления устройством
18	022	0x12	00010010	DC2			2-й символ управления устройством
19	023	0x13	00010011	DC3			3-й символ управления устройством
20	024	0x14	00010100	DC4			4-й символ управления устройством
21	025	0x15	00010101	NAK			«Не подтверждаю!»
22	026	0x16	00010110	SYN			Символ для синхронизации
23	027	0x17	00010111	ETB			Конец текстового блока
24	030	0x18	00011000	CAN			Отмена
25	031	0x19	00011001	EM			Конец носителя
26	032	0x1A	00011010	SUB			Подставить
27	033	0x1B	00011011	ESC	e		Escape (Расширение)
28	034	0x1C	00011100	FS			Разделитель файлов
29	035	0x1D	00011101	GS			Разделитель групп
30	036	0x1E	00011110	RS			Разделитель записей
31	037	0x1F	00011111	US			Разделитель юнитов
127	177	0x7F	01111111	Delete			Символ для удаления (на перфолентах)

2

Печатные символы

DEC	OCT	HEX	BIN	Символ	HTML код	Мнемоника
32	040	0x20	00100000	Пробел
33	041	0x21	00100001	!	!
34	042	0x22	00100010	«	"	"
35	043	0x23	00100011	#	#
36	044	0x24	00100100	$	$
37	045	0x25	00100101	%	%
38	046	0x26	00100110	&	&	&
39	047	0x27	00100111	‘	'	'
40	050	0x28	00101000	(	(
41	051	0x29	00101001	)	)
42	052	0x2A	00101010	*	*
43	053	0x2B	00101011	+	+
44	054	0x2C	00101100	,	,
45	055	0x2D	00101101	—	-
46	056	0x2E	00101110	.	.
47	057	0x2F	00101111	/	/
48	060	0x30	00110000	0	0
49	061	0x31	00110001	1	1
50	062	0x32	00110010	2	2
51	063	0x33	00110011	3	3
52	064	0x34	00110100	4	4
53	065	0x35	00110101	5	5
54	066	0x36	00110110	6	6
55	067	0x37	00110111	7	7
56	070	0x38	00111000	8	8
57	071	0x39	00111001	9	9
58	072	0x3A	00111010	:	:
59	073	0x3B	00111011	;	;
60	074	0x3C	00111100	<	<	&lt;
61	075	0x3D	00111101	=	=
62	076	0x3E	00111110	>	>	&gt;
63	077	0x3F	00111111	?	?
64	100	0x40	01000000	@	@
65	101	0x41	01000001	A	A
66	102	0x42	01000010	B	B
67	103	0x43	01000011	C	C
68	104	0x44	01000100	D	D
69	105	0x45	01000101	E	E
70	106	0x46	01000110	F	F
71	107	0x47	01000111	G	G
72	110	0x48	01001000	H	H
73	111	0x49	01001001	I	I
74	112	0x4A	01001010	J	J
75	113	0x4B	01001011	K	K
76	114	0x4C	01001100	L	L
77	115	0x4D	01001101	M	M
78	116	0x4E	01001110	N	N
79	117	0x4F	01001111	O	O
80	120	0x50	01010000	P	P
81	121	0x51	01010001	Q	Q
82	122	0x52	01010010	R	R
83	123	0x53	01010011	S	S
84	124	0x54	01010100	T	T
85	125	0x55	01010101	U	U
86	126	0x56	01010110	V	V
87	127	0x57	01010111	W	W
88	130	0x58	01011000	X	X
89	131	0x59	01011001	Y	Y
90	132	0x5A	01011010	Z	Z
91	133	0x5B	01011011	[	[
92	134	0x5C	01011100		\
93	135	0x5D	01011101	]	]
94	136	0x5E	01011110	^	^
95	137	0x5F	01011111	_	_
96	140	0x60	01100000	`	`
97	141	0x61	01100001	a	a
98	142	0x62	01100010	b	b
99	143	0x63	01100011	c	c
100	144	0x64	01100100	d	d
101	145	0x65	01100101	e	e
102	146	0x66	01100110	f	f
103	147	0x67	01100111	g	g
104	150	0x68	01101000	h	h
105	151	0x69	01101001	i	i
106	152	0x6A	01101010	j	j
107	153	0x6B	01101011	k	k
108	154	0x6C	01101100	l	l
109	155	0x6D	01101101	m	m
110	156	0x6E	01101110	n	n
111	157	0x6F	01101111	o	o
112	160	0x70	01110000	p	p
113	161	0x71	01110001	q	q
114	162	0x72	01110010	r	r
115	163	0x73	01110011	s	s
116	164	0x74	01110100	t	t
117	165	0x75	01110101	u	u
118	166	0x76	01110110	v	v
119	167	0x77	01110111	w	w
120	170	0x78	01111000	x	x
121	171	0x79	01111001	y	y
122	172	0x7A	01111010	z	z
123	173	0x7B	01111011	{	{
124	174	0x7C	01111100	|	|
125	175	0x7D	01111101	}	}
126	176	0x7E	01111110	~	~

3

Расширенные символы ASCII Win-1251 кириллица

DEC	OCT	HEX	BIN	Символ	HTML код	Мнемоника
128	200	0x80	10000000	Ђ	€
129	201	0x81	10000001	Ѓ	
130	202	0x82	10000010	‚	‚	‚
131	203	0x83	10000011	ѓ	ƒ
132	204	0x84	10000100	„	„	„
133	205	0x85	10000101	…	…	…
134	206	0x86	10000110	†	†	†
135	207	0x87	10000111	‡	‡	‡
136	210	0x88	10001000	€	ˆ	€
137	211	0x89	10001001	‰	‰	‰
138	212	0x8A	10001010	Љ	Š
139	213	0x8B	10001011	‹	‹	‹
140	214	0x8C	10001100	Њ	Œ
141	215	0x8D	10001101	Ќ	
142	216	0x8E	10001110	Ћ	Ž
143	217	0x8F	10001111	Џ	
144	220	0x90	10010000	Ђ	
145	221	0x91	10010001	‘	‘	‘
146	222	0x92	10010010	’	’	’
147	223	0x93	10010011	“	“	“
148	224	0x94	10010100	”	”	”
149	225	0x95	10010101	•	•	•
150	226	0x96	10010110	–	–	–
151	227	0x97	10010111	—	—	—
152	230	0x98	10011000	Начало строки	˜
153	231	0x99	10011001	™	™	™
154	232	0x9A	10011010	љ	š
155	233	0x9B	10011011	›	›	›
156	234	0x9C	10011100	њ	œ
157	235	0x9D	10011101	ќ	
158	236	0x9E	10011110	ћ	ž
159	237	0x9F	10011111	џ	Ÿ
160	240	0xA0	10100000	Неразрывный пробел		 
161	241	0xA1	10100001	Ў	¡
162	242	0xA2	10100010	ў	¢
163	243	0xA3	10100011	Ј	£
164	244	0xA4	10100100	¤	¤	¤
165	245	0xA5	10100101	Ґ	¥
166	246	0xA6	10100110	¦	¦	¦
167	247	0xA7	10100111	§	§	§
168	250	0xA8	10101000	Ё	¨
169	251	0xA9	10101001	©	©	©
170	252	0xAA	10101010	Є	ª
171	253	0xAB	10101011	«	«	«
172	254	0xAC	10101100	¬	¬	¬
173	255	0xAD	10101101	Мягкий перенос	­	­
174	256	0xAE	10101110	®	®	®
175	257	0xAF	10101111	Ї	¯
176	260	0xB0	10110000	°	°	°
177	261	0xB1	10110001	±	±	±
178	262	0xB2	10110010	І	²
179	263	0xB3	10110011	і	³
180	264	0xB4	10110100	ґ	´
181	265	0xB5	10110101	µ	µ	µ
182	266	0xB6	10110110	¶	¶	¶
183	267	0xB7	10110111	·	·	·
184	270	0xB8	10111000	ё	¸
185	271	0xB9	10111001	№	¹
186	272	0xBA	10111010	є	º
187	273	0xBB	10111011	»	»	»
188	274	0xBC	10111100	ј	¼
189	275	0xBD	10111101	Ѕ	½
190	276	0xBE	10111110	ѕ	¾
191	277	0xBF	10111111	ї	¿
192	300	0xC0	11000000	А	À
193	301	0xC1	11000001	Б	Á
194	302	0xC2	11000010	В	Â
195	303	0xC3	11000011	Г	Ã
196	304	0xC4	11000100	Д	Ä
197	305	0xC5	11000101	Е	Å
198	306	0xC6	11000110	Ж	Æ
199	307	0xC7	11000111	З	Ç
200	310	0xC8	11001000	И	È
201	311	0xC9	11001001	Й	É
202	312	0xCA	11001010	К	Ê
203	313	0xCB	11001011	Л	Ë
204	314	0xCC	11001100	М	Ì
205	315	0xCD	11001101	Н	Í
206	316	0xCE	11001110	О	Î
207	317	0xCF	11001111	П	Ï
208	320	0xD0	11010000	Р	Ð
209	321	0xD1	11010001	С	Ñ
210	322	0xD2	11010010	Т	Ò
211	323	0xD3	11010011	У	Ó
212	324	0xD4	11010100	Ф	Ô
213	325	0xD5	11010101	Х	Õ
214	326	0xD6	11010110	Ц	Ö
215	327	0xD7	11010111	Ч	×
216	330	0xD8	11011000	Ш	Ø
217	331	0xD9	11011001	Щ	Ù
218	332	0xDA	11011010	Ъ	Ú
219	333	0xDB	11011011	Ы	Û
220	334	0xDC	11011100	Ь	Ü
221	335	0xDD	11011101	Э	Ý
222	336	0xDE	11011110	Ю	Þ
223	337	0xDF	11011111	Я	ß
224	340	0xE0	11100000	а	à
225	341	0xE1	11100001	б	á
226	342	0xE2	11100010	в	â
227	343	0xE3	11100011	г	ã
228	344	0xE4	11100100	д	ä
229	345	0xE5	11100101	е	å
230	346	0xE6	11100110	ж	æ
231	347	0xE7	11100111	з	ç
232	350	0xE8	11101000	и	è
233	351	0xE9	11101001	й	é
234	352	0xEA	11101010	к	ê
235	353	0xEB	11101011	л	ë
236	354	0xEC	11101100	м	ì
237	355	0xED	11101101	н	í
238	356	0xEE	11101110	о	î
239	357	0xEF	11101111	п	ï
240	360	0xF0	11110000	р	ð
241	361	0xF1	11110001	с	ñ
242	362	0xF2	11110010	т	ò
243	363	0xF3	11110011	у	ó
244	364	0xF4	11110100	ф	ô
245	365	0xF5	11110101	х	õ
246	366	0xF6	11110110	ц	ö
247	367	0xF7	11110111	ч	÷
248	370	0xF8	11111000	ш	ø
249	371	0xF9	11111001	щ	ù
250	372	0xFA	11111010	ъ	ú
251	373	0xFB	11111011	ы	û
252	374	0xFC	11111100	ь	ü
253	375	0xFD	11111101	э	ý
254	376	0xFE	11111110	ю	þ
255	377	0xFF	11111111	я	ÿ

This article is about the character encoding. For other uses, see ASCII (disambiguation).

ASCII

ASCII chart from MIL-STD-188-100 (1972)
MIME / IANA	us-ascii
Alias(es)	ISO-IR-006,[1] ANSI_X3.4-1968, ANSI_X3.4-1986, ISO_646.irv:1991, ISO646-US, us, IBM367, cp367[2]
Language(s)	English (made for; does not support all loanwords), Malay, Rotokas, Interlingua, Ido, and X-SAMPA
Classification	ISO/IEC 646 series
Extensions	Unicode ISO/IEC 8859 (series) KOI-8 OEM (series) Windows-125x (series) Others
Preceded by	ITA 2, FIELDATA
Succeeded by	ISO/IEC 8859, ISO/IEC 10646 (Unicode)
v t e

ASCII ( ASS-kee),^[3]: 6 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 of technical limitations of computer systems at the time it was invented, ASCII has just 128 code points, of which only 95 are printable characters, which severely limited its scope. Many computer systems instead use Unicode, which has millions of code points, but the first 128 of these are the same as the ASCII set.

The Internet Assigned Numbers Authority (IANA) prefers the name US-ASCII for this character encoding.^[2]

ASCII is one of the IEEE milestones.

Overview[edit]

ASCII was developed from telegraph code. Its first commercial use was as a seven-bit teleprinter code promoted by Bell data services.^[when?] Work on the ASCII standard began in May 1961, with the first meeting of the American Standards Association’s (ASA) (now the American National Standards Institute or ANSI) X3.2 subcommittee. The first edition of the standard was published in 1963,^[4][5] underwent a major revision during 1967,^[6][7] and experienced its most recent update during 1986.^[8] Compared to earlier telegraph codes, the proposed Bell code and ASCII were both ordered for more convenient sorting (i.e., alphabetization) of lists and added features for devices other than teleprinters.^[8]

The use of ASCII format for Network Interchange was described in 1969.^[9] That document was formally elevated to an Internet Standard in 2015.^[10]

Originally based on the (modern) English alphabet, ASCII encodes 128 specified characters into seven-bit integers as shown by the ASCII chart above.^[11] Ninety-five of the encoded characters are printable: these include the digits 0 to 9, lowercase letters a to z, uppercase letters A to Z, and punctuation symbols. In addition, the original ASCII specification included 33 non-printing control codes which originated with Teletype machines; most of these are now obsolete,^[12] although a few are still commonly used, such as the carriage return, line feed, and tab codes.

For example, lowercase i would be represented in the ASCII encoding by binary 1101001 = hexadecimal 69 (i is the ninth letter) = decimal 105.

Despite being an American standard, ASCII does not have a code point for the cent (¢). It also does not support English terms with diacritical marks such as résumé and jalapeño, or proper nouns with diacritical marks such as Beyoncé.

History[edit]

The American Standard Code for Information Interchange (ASCII) was developed under the auspices of a committee of the American Standards Association (ASA), called the X3 committee, by its X3.2 (later X3L2) subcommittee, and later by that subcommittee’s X3.2.4 working group (now INCITS). The ASA later became the United States of America Standards Institute (USASI),^[3]: 211 and ultimately became the American National Standards Institute (ANSI).

With the other special characters and control codes filled in, ASCII was published as ASA X3.4-1963,^[5][13] leaving 28 code positions without any assigned meaning, reserved for future standardization, and one unassigned control code.^{[3]: 66, 245} There was some debate at the time whether there should be more control characters rather than the lowercase alphabet.^[3]: 435 The indecision did not last long: during May 1963 the CCITT Working Party on the New Telegraph Alphabet proposed to assign lowercase characters to sticks^[a][14] 6 and 7,^[15] and International Organization for Standardization TC 97 SC 2 voted during October to incorporate the change into its draft standard.^[16] The X3.2.4 task group voted its approval for the change to ASCII at its May 1963 meeting.^[17] Locating the lowercase letters in sticks^[a][14] 6 and 7 caused the characters to differ in bit pattern from the upper case by a single bit, which simplified case-insensitive character matching and the construction of keyboards and printers.

The X3 committee made other changes, including other new characters (the brace and vertical bar characters),^[18] renaming some control characters (SOM became start of header (SOH)) and moving or removing others (RU was removed).^{[3]: 247–248} ASCII was subsequently updated as USAS X3.4-1967,^[6][19] then USAS X3.4-1968, ANSI X3.4-1977, and finally, ANSI X3.4-1986.^[8][20]

Revisions of the ASCII standard:

• ASA X3.4-1963^{[3][5][19][20]}
• ASA X3.4-1965 (approved, but not published, nevertheless used by IBM 2260 & 2265 Display Stations and IBM 2848 Display Control)^{[3]: 423, 425–428, 435–439 [21][19][20]}
• USAS X3.4-1967^[3][6][20]
• USAS X3.4-1968^[3][20]
• ANSI X3.4-1977^[20]
• ANSI X3.4-1986^[8][20]
• ANSI X3.4-1986 (R1992)
• ANSI X3.4-1986 (R1997)
• ANSI INCITS 4-1986 (R2002)^[22]
• ANSI INCITS 4-1986 (R2007)^[23]
• (ANSI) INCITS 4-1986[R2012]^[24]
• (ANSI) INCITS 4-1986[R2017]^[25]

In the X3.15 standard, the X3 committee also addressed how ASCII should be transmitted (least significant bit first),^{[3]: 249–253 [26]} and how it should be recorded on perforated tape. They proposed a 9-track standard for magnetic tape, and attempted to deal with some punched card formats.

Design considerations[edit]

Bit width[edit]

The X3.2 subcommittee designed ASCII based on the earlier teleprinter encoding systems. Like other character encodings, ASCII specifies a correspondence between digital bit patterns and character symbols (i.e. graphemes and control characters). This allows digital devices to communicate with each other and to process, store, and communicate character-oriented information such as written language. Before ASCII was developed, the encodings in use included 26 alphabetic characters, 10 numerical digits, and from 11 to 25 special graphic symbols. To include all these, and control characters compatible with the Comité Consultatif International Téléphonique et Télégraphique (CCITT) International Telegraph Alphabet No. 2 (ITA2) standard of 1924,^[27][28] FIELDATA (1956^{[citation needed]}), and early EBCDIC (1963), more than 64 codes were required for ASCII.

ITA2 was in turn based on the 5-bit telegraph code that Émile Baudot invented in 1870 and patented in 1874.^[28]

The committee debated the possibility of a shift function (like in ITA2), which would allow more than 64 codes to be represented by a six-bit code. In a shifted code, some character codes determine choices between options for the following character codes. It allows compact encoding, but is less reliable for data transmission, as an error in transmitting the shift code typically makes a long part of the transmission unreadable. The standards committee decided against shifting, and so ASCII required at least a seven-bit code.^{[3]: 215 §13.6, 236 §4}

The committee considered an eight-bit code, since eight bits (octets) would allow two four-bit patterns to efficiently encode two digits with binary-coded decimal. However, it would require all data transmission to send eight bits when seven could suffice. The committee voted to use a seven-bit code to minimize costs associated with data transmission. Since perforated tape at the time could record eight bits in one position, it also allowed for a parity bit for error checking if desired.^{[3]: 217 §c, 236 §5} Eight-bit machines (with octets as the native data type) that did not use parity checking typically set the eighth bit to 0.^[29]

Internal organization[edit]

The code itself was patterned so that most control codes were together and all graphic codes were together, for ease of identification. The first two so-called ASCII sticks^[a][14] (32 positions) were reserved for control characters.^{[3]: 220, 236 8, 9)} The «space» character had to come before graphics to make sorting easier, so it became position 20_hex;^{[3]: 237 §10} for the same reason, many special signs commonly used as separators were placed before digits. The committee decided it was important to support uppercase 64-character alphabets, and chose to pattern ASCII so it could be reduced easily to a usable 64-character set of graphic codes,^{[3]: 228, 237 §14} as was done in the DEC SIXBIT code (1963). Lowercase letters were therefore not interleaved with uppercase. To keep options available for lowercase letters and other graphics, the special and numeric codes were arranged before the letters, and the letter A was placed in position 41_hex to match the draft of the corresponding British standard.^{[3]: 238 §18} The digits 0–9 are prefixed with 011, but the remaining 4 bits correspond to their respective values in binary, making conversion with binary-coded decimal straightforward (for example, 5 in encoded to 0110101, where 5 is 0101 in binary).

Many of the non-alphanumeric characters were positioned to correspond to their shifted position on typewriters; an important subtlety is that these were based on mechanical typewriters, not electric typewriters.^[30] Mechanical typewriters followed the de facto standard set by the Remington No. 2 (1878), the first typewriter with a shift key, and the shifted values of 23456789- were "#$%_&'() – early typewriters omitted 0 and 1, using O (capital letter o) and l (lowercase letter L) instead, but 1! and 0) pairs became standard once 0 and 1 became common. Thus, in ASCII !"#$% were placed in the second stick,^[a][14] positions 1–5, corresponding to the digits 1–5 in the adjacent stick.^[a][14] The parentheses could not correspond to 9 and 0, however, because the place corresponding to 0 was taken by the space character. This was accommodated by removing _ (underscore) from 6 and shifting the remaining characters, which corresponded to many European typewriters that placed the parentheses with 8 and 9. This discrepancy from typewriters led to bit-paired keyboards, notably the Teletype Model 33, which used the left-shifted layout corresponding to ASCII, differently from traditional mechanical typewriters.

Electric typewriters, notably the IBM Selectric (1961), used a somewhat different layout that has become de facto standard on computers – following the IBM PC (1981), especially Model M (1984) – and thus shift values for symbols on modern keyboards do not correspond as closely to the ASCII table as earlier keyboards did. The /? pair also dates to the No. 2, and the ,< .> pairs were used on some keyboards (others, including the No. 2, did not shift , (comma) or . (full stop) so they could be used in uppercase without unshifting). However, ASCII split the ;: pair (dating to No. 2), and rearranged mathematical symbols (varied conventions, commonly -* =+) to :* ;+ -=.

Some then-common typewriter characters were not included, notably ½ ¼ ¢, while ^ ` ~ were included as diacritics for international use, and < > for mathematical use, together with the simple line characters | (in addition to common /). The @ symbol was not used in continental Europe and the committee expected it would be replaced by an accented À in the French variation, so the @ was placed in position 40_hex, right before the letter A.^[3]: 243

The control codes felt essential for data transmission were the start of message (SOM), end of address (EOA), end of message (EOM), end of transmission (EOT), «who are you?» (WRU), «are you?» (RU), a reserved device control (DC0), synchronous idle (SYNC), and acknowledge (ACK). These were positioned to maximize the Hamming distance between their bit patterns.^{[3]: 243–245}

Character order[edit]

ASCII-code order is also called ASCIIbetical order.^[31] Collation of data is sometimes done in this order rather than «standard» alphabetical order (collating sequence). The main deviations in ASCII order are:

• All uppercase come before lowercase letters; for example, «Z» precedes «a»
• Digits and many punctuation marks come before letters

An intermediate order converts uppercase letters to lowercase before comparing ASCII values.

Character groups[edit]

Control characters[edit]

ASCII reserves the first 32 codes (numbers 0–31 decimal) for control characters, which are characters originally intended not to represent printable information, but rather to control devices (such as printers) that make use of ASCII, or to provide meta-information about data streams such as those stored on magnetic tape.

For example, character 0x0A represents the «line feed» function (which causes a printer to advance its paper), and character 8 represents «backspace». RFC 2822 refers to control characters that do not include carriage return, line feed or white space as non-whitespace control characters.^[32] Except for the control characters that prescribe elementary line-oriented formatting, ASCII does not define any mechanism for describing the structure or appearance of text within a document. Other schemes, such as markup languages, address page and document layout and formatting.

The original ASCII standard used only short descriptive phrases for each control character. The ambiguity this caused was sometimes intentional, for example where a character would be used slightly differently on a terminal link than on a data stream, and sometimes accidental, for example with the meaning of «delete».

Probably the most influential single device affecting the interpretation of these characters was the Teletype Model 33 ASR, which was a printing terminal with an available paper tape reader/punch option. Paper tape was a very popular medium for long-term program storage until the 1980s, less costly and in some ways less fragile than magnetic tape. In particular, the Teletype Model 33 machine assignments for codes 17 (control-Q, DC1, also known as XON), 19 (control-S, DC3, also known as XOFF), and 127 (delete) became de facto standards. The Model 33 was also notable for taking the description of control-G (code 7, BEL, meaning audibly alert the operator) literally, as the unit contained an actual bell which it rang when it received a BEL character. Because the keytop for the O key also showed a left-arrow symbol (from ASCII-1963, which had this character instead of underscore), a noncompliant use of code 15 (control-O, shift in) interpreted as «delete previous character» was also adopted by many early timesharing systems but eventually became neglected.

When a Teletype 33 ASR equipped with the automatic paper tape reader received a control-S (XOFF, an abbreviation for transmit off), it caused the tape reader to stop; receiving control-Q (XON, transmit on) caused the tape reader to resume. This so-called flow control technique became adopted by several early computer operating systems as a «handshaking» signal warning a sender to stop transmission because of impending buffer overflow; it persists to this day in many systems as a manual output control technique. On some systems, control-S retains its meaning but control-Q is replaced by a second control-S to resume output.

The 33 ASR also could be configured to employ control-R (DC2) and control-T (DC4) to start and stop the tape punch; on some units equipped with this function, the corresponding control character lettering on the keycap above the letter was TAPE and TAPE respectively.^[33]

Delete vs backspace[edit]

The Teletype could not move its typehead backwards, so it did not have a key on its keyboard to send a BS (backspace). Instead, there was a key marked RUB OUT that sent code 127 (DEL). The purpose of this key was to erase mistakes in a manually-input paper tape: the operator had to push a button on the tape punch to back it up, then type the rubout, which punched all holes and replaced the mistake with a character that was intended to be ignored.^[34] Teletypes were commonly used with the less-expensive computers from Digital Equipment Corporation (DEC); these systems had to use what keys were available, and thus the DEL character was assigned to erase the previous character.^[35][36] Because of this, DEC video terminals (by default) sent the DEL character for the key marked «Backspace» while the separate key marked «Delete» sent an escape sequence; many other competing terminals sent a BS character for the backspace key.

The Unix terminal driver could only use one character to erase the previous character, this could be set to BS or DEL, but not both, resulting in recurring situations of ambiguity where users had to decide depending on what terminal they were using (shells that allow line editing, such as ksh, bash, and zsh, understand both). The assumption that no key sent a BS character allowed control+H to be used for other purposes, such as the «help» prefix command in GNU Emacs.^[37]

Escape[edit]

Many more of the control characters have been assigned meanings quite different from their original ones. The «escape» character (ESC, code 27), for example, was intended originally to allow sending of other control characters as literals instead of invoking their meaning, an «escape sequence». This is the same meaning of «escape» encountered in URL encodings, C language strings, and other systems where certain characters have a reserved meaning. Over time this interpretation has been co-opted and has eventually been changed.

In modern usage, an ESC sent to the terminal usually indicates the start of a command sequence usually in the form of a so-called «ANSI escape code» (or, more properly, a «Control Sequence Introducer») from ECMA-48 (1972) and its successors, beginning with ESC followed by a «[» (left-bracket) character. In contrast, an ESC sent from the terminal is most often used as an out-of-band character used to terminate an operation or special mode, as in the TECO and vi text editors. In graphical user interface (GUI) and windowing systems, ESC generally causes an application to abort its current operation or to exit (terminate) altogether.

End of line[edit]

The inherent ambiguity of many control characters, combined with their historical usage, created problems when transferring «plain text» files between systems. The best example of this is the newline problem on various operating systems. Teletype machines required that a line of text be terminated with both «carriage return» (which moves the printhead to the beginning of the line) and «line feed» (which advances the paper one line without moving the printhead). The name «carriage return» comes from the fact that on a manual typewriter the carriage holding the paper moves while the typebars that strike the ribbon remain stationary. The entire carriage had to be pushed (returned) to the right in order to position the paper for the next line.

DEC operating systems (OS/8, RT-11, RSX-11, RSTS, TOPS-10, etc.) used both characters to mark the end of a line so that the console device (originally Teletype machines) would work. By the time so-called «glass TTYs» (later called CRTs or «dumb terminals») came along, the convention was so well established that backward compatibility necessitated continuing to follow it. When Gary Kildall created CP/M, he was inspired by some of the command line interface conventions used in DEC’s RT-11 operating system.

Until the introduction of PC DOS in 1981, IBM had no influence in this because their 1970s operating systems used EBCDIC encoding instead of ASCII, and they were oriented toward punch-card input and line printer output on which the concept of «carriage return» was meaningless. IBM’s PC DOS (also marketed as MS-DOS by Microsoft) inherited the convention by virtue of being loosely based on CP/M,^[38] and Windows in turn inherited it from MS-DOS.

Requiring two characters to mark the end of a line introduces unnecessary complexity and ambiguity as to how to interpret each character when encountered by itself. To simplify matters, plain text data streams, including files, on Multics used line feed (LF) alone as a line terminator.^[39]: 357 Unix and Unix-like systems, and Amiga systems, adopted this convention from Multics. On the other hand, the original Macintosh OS, Apple DOS, and ProDOS used carriage return (CR) alone as a line terminator; however, since Apple has now replaced these obsolete operating systems with the Unix-based macOS operating system, they now use line feed (LF) as well. The Radio Shack TRS-80 also used a lone CR to terminate lines.

Computers attached to the ARPANET included machines running operating systems such as TOPS-10 and TENEX using CR-LF line endings; machines running operating systems such as Multics using LF line endings; and machines running operating systems such as OS/360 that represented lines as a character count followed by the characters of the line and which used EBCDIC rather than ASCII encoding. The Telnet protocol defined an ASCII «Network Virtual Terminal» (NVT), so that connections between hosts with different line-ending conventions and character sets could be supported by transmitting a standard text format over the network. Telnet used ASCII along with CR-LF line endings, and software using other conventions would translate between the local conventions and the NVT.^[40] The File Transfer Protocol adopted the Telnet protocol, including use of the Network Virtual Terminal, for use when transmitting commands and transferring data in the default ASCII mode.^[41][42] This adds complexity to implementations of those protocols, and to other network protocols, such as those used for E-mail and the World Wide Web, on systems not using the NVT’s CR-LF line-ending convention.^[43][44]

End of file/stream[edit]

The PDP-6 monitor,^[35] and its PDP-10 successor TOPS-10,^[36] used control-Z (SUB) as an end-of-file indication for input from a terminal. Some operating systems such as CP/M tracked file length only in units of disk blocks, and used control-Z to mark the end of the actual text in the file.^[45] For these reasons, EOF, or end-of-file, was used colloquially and conventionally as a three-letter acronym for control-Z instead of SUBstitute. The end-of-text character (ETX), also known as control-C, was inappropriate for a variety of reasons, while using control-Z as the control character to end a file is analogous to the letter Z’s position at the end of the alphabet, and serves as a very convenient mnemonic aid. A historically common and still prevalent convention uses the ETX character convention to interrupt and halt a program via an input data stream, usually from a keyboard.

The Unix terminal driver uses the end-of-transmission character (EOT), also known as control-D, to indicate the end of a data stream.

In the C programming language, and in Unix conventions, the null character is used to terminate text strings; such null-terminated strings can be known in abbreviation as ASCIZ or ASCIIZ, where here Z stands for «zero».

Control code chart[edit]

Binary	Oct	Dec	Hex	Abbreviation	Unicode Control Pictures[b]	Caret notation[c]	C escape sequence[d]	Name (1967)
1963	1965	1967
000 0000	000	0	00	NULL	NUL	␀	^@		Null
000 0001	001	1	01	SOM	SOH	␁	^A		Start of Heading
000 0010	002	2	02	EOA	STX	␂	^B		Start of Text
000 0011	003	3	03	EOM	ETX	␃	^C		End of Text
000 0100	004	4	04	EOT	␄	^D		End of Transmission
000 0101	005	5	05	WRU	ENQ	␅	^E		Enquiry
000 0110	006	6	06	RU	ACK	␆	^F		Acknowledgement
000 0111	007	7	07	BELL	BEL	␇	^G	a	Bell
000 1000	010	8	08	FE0	BS	␈	^H	b	Backspace[e][f]
000 1001	011	9	09	HT/SK	HT	␉	^I	t	Horizontal Tab[g]
000 1010	012	10	0A	LF	␊	^J	n	Line Feed
000 1011	013	11	0B	VTAB	VT	␋	^K	v	Vertical Tab
000 1100	014	12	0C	FF	␌	^L	f	Form Feed
000 1101	015	13	0D	CR	␍	^M	r	Carriage Return[h]
000 1110	016	14	0E	SO	␎	^N		Shift Out
000 1111	017	15	0F	SI	␏	^O		Shift In
001 0000	020	16	10	DC0	DLE	␐	^P		Data Link Escape
001 0001	021	17	11	DC1	␑	^Q		Device Control 1 (often XON)
001 0010	022	18	12	DC2	␒	^R		Device Control 2
001 0011	023	19	13	DC3	␓	^S		Device Control 3 (often XOFF)
001 0100	024	20	14	DC4	␔	^T		Device Control 4
001 0101	025	21	15	ERR	NAK	␕	^U		Negative Acknowledgement
001 0110	026	22	16	SYNC	SYN	␖	^V		Synchronous Idle
001 0111	027	23	17	LEM	ETB	␗	^W		End of Transmission Block
001 1000	030	24	18	S0	CAN	␘	^X		Cancel
001 1001	031	25	19	S1	EM	␙	^Y		End of Medium
001 1010	032	26	1A	S2	SS	SUB	␚	^Z		Substitute
001 1011	033	27	1B	S3	ESC	␛	^[	e[i]	Escape[j]
001 1100	034	28	1C	S4	FS	␜	^		File Separator
001 1101	035	29	1D	S5	GS	␝	^]		Group Separator
001 1110	036	30	1E	S6	RS	␞	^^[k]		Record Separator
001 1111	037	31	1F	S7	US	␟	^_		Unit Separator
111 1111	177	127	7F	DEL	␡	^?		Delete[l][f]

Other representations might be used by specialist equipment, for example ISO 2047 graphics or hexadecimal numbers.

Printable characters[edit]

Codes 20_hex to 7E_hex, known as the printable characters, represent letters, digits, punctuation marks, and a few miscellaneous symbols. There are 95 printable characters in total.^[m]

Code 20_hex, the «space» character, denotes the space between words, as produced by the space bar of a keyboard. Since the space character is considered an invisible graphic (rather than a control character)^{[3]: 223 [46]} it is listed in the table below instead of in the previous section.

Code 7F_hex corresponds to the non-printable «delete» (DEL) control character and is therefore omitted from this chart; it is covered in the previous section’s chart. Earlier versions of ASCII used the up arrow instead of the caret (5E_hex) and the left arrow instead of the underscore (5F_hex).^[5][47]

Binary	Oct	Dec	Hex	Glyph
1963	1965	1967
010 0000	040	32	20	space
010 0001	041	33	21	!
010 0010	042	34	22	«
010 0011	043	35	23	#
010 0100	044	36	24	$
010 0101	045	37	25	%
010 0110	046	38	26	&
010 0111	047	39	27	‘
010 1000	050	40	28	(
010 1001	051	41	29	)
010 1010	052	42	2A	*
010 1011	053	43	2B	+
010 1100	054	44	2C	,
010 1101	055	45	2D	—
010 1110	056	46	2E	.
010 1111	057	47	2F	/
011 0000	060	48	30	0
011 0001	061	49	31	1
011 0010	062	50	32	2
011 0011	063	51	33	3
011 0100	064	52	34	4
011 0101	065	53	35	5
011 0110	066	54	36	6
011 0111	067	55	37	7
011 1000	070	56	38	8
011 1001	071	57	39	9
011 1010	072	58	3A	:
011 1011	073	59	3B	;
011 1100	074	60	3C	<
011 1101	075	61	3D	=
011 1110	076	62	3E	>
011 1111	077	63	3F	?
100 0000	100	64	40	@	`	@
100 0001	101	65	41	A
100 0010	102	66	42	B
100 0011	103	67	43	C
100 0100	104	68	44	D
100 0101	105	69	45	E
100 0110	106	70	46	F
100 0111	107	71	47	G
100 1000	110	72	48	H
100 1001	111	73	49	I
100 1010	112	74	4A	J
100 1011	113	75	4B	K
100 1100	114	76	4C	L
100 1101	115	77	4D	M
100 1110	116	78	4E	N
100 1111	117	79	4F	O
101 0000	120	80	50	P
101 0001	121	81	51	Q
101 0010	122	82	52	R
101 0011	123	83	53	S
101 0100	124	84	54	T
101 0101	125	85	55	U
101 0110	126	86	56	V
101 0111	127	87	57	W
101 1000	130	88	58	X
101 1001	131	89	59	Y
101 1010	132	90	5A	Z
101 1011	133	91	5B	[
101 1100	134	92	5C		~
101 1101	135	93	5D	]
101 1110	136	94	5E	↑	^
101 1111	137	95	5F	←	_
110 0000	140	96	60		@	`
110 0001	141	97	61		a
110 0010	142	98	62		b
110 0011	143	99	63		c
110 0100	144	100	64		d
110 0101	145	101	65		e
110 0110	146	102	66		f
110 0111	147	103	67		g
110 1000	150	104	68		h
110 1001	151	105	69		i
110 1010	152	106	6A		j
110 1011	153	107	6B		k
110 1100	154	108	6C		l
110 1101	155	109	6D		m
110 1110	156	110	6E		n
110 1111	157	111	6F		o
111 0000	160	112	70		p
111 0001	161	113	71		q
111 0010	162	114	72		r
111 0011	163	115	73		s
111 0100	164	116	74		t
111 0101	165	117	75		u
111 0110	166	118	76		v
111 0111	167	119	77		w
111 1000	170	120	78		x
111 1001	171	121	79		y
111 1010	172	122	7A		z
111 1011	173	123	7B		{
111 1100	174	124	7C	ACK	¬	|
111 1101	175	125	7D		}
111 1110	176	126	7E	ESC	|	~

Character set[edit]

ASCII (1977/1986)

0

1

2

3

4

5

6

7

8

9

A

B

C

D

E

F

0x

NUL

SOH

STX

ETX

EOT

ENQ

ACK

BEL

BS

HT

LF

VT

FF

CR

SO

SI

1x

DLE

DC1

DC2

DC3

DC4

NAK

SYN

ETB

CAN

EM

SUB

ESC

FS

GS

RS

US

2x

SP

!

»

#

$

%

&

‘

(

)

*

+

,

—

.

/

3x

0

1

2

3

4

5

6

7

8

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

{

|

}

~

DEL

Changed or added in 1963 version   Changed in both 1963 version and 1965 draft

Usage[edit]

ASCII was first used commercially during 1963 as a seven-bit teleprinter code for American Telephone & Telegraph’s TWX (TeletypeWriter eXchange) network. TWX originally used the earlier five-bit ITA2, which was also used by the competing Telex teleprinter system. Bob Bemer introduced features such as the escape sequence.^[4] His British colleague Hugh McGregor Ross helped to popularize this work – according to Bemer, «so much so that the code that was to become ASCII was first called the Bemer–Ross Code in Europe».^[48] Because of his extensive work on ASCII, Bemer has been called «the father of ASCII».^[49]

On March 11, 1968, US President Lyndon B. Johnson mandated that all computers purchased by the United States Federal Government support ASCII, stating:^[50][51][52]

I have also approved recommendations of the Secretary of Commerce [Luther H. Hodges] regarding standards for recording the Standard Code for Information Interchange on magnetic tapes and paper tapes when they are used in computer operations.
All computers and related equipment configurations brought into the Federal Government inventory on and after July 1, 1969, must have the capability to use the Standard Code for Information Interchange and the formats prescribed by the magnetic tape and paper tape standards when these media are used.

ASCII was the most common character encoding on the World Wide Web until December 2007, when UTF-8 encoding surpassed it; UTF-8 is backward compatible with ASCII.^[53][54][55]

Variants and derivations[edit]

As computer technology spread throughout the world, different standards bodies and corporations developed many variations of ASCII to facilitate the expression of non-English languages that used Roman-based alphabets. One could class some of these variations as «ASCII extensions», although some misuse that term to represent all variants, including those that do not preserve ASCII’s character-map in the 7-bit range. Furthermore, the ASCII extensions have also been mislabelled as ASCII.

7-bit codes[edit]

From early in its development,^[56] ASCII was intended to be just one of several national variants of an international character code standard.

Other international standards bodies have ratified character encodings such as ISO 646 (1967) that are identical or nearly identical to ASCII, with extensions for characters outside the English alphabet and symbols used outside the United States, such as the symbol for the United Kingdom’s pound sterling (£); e.g. with code page 1104. Almost every country needed an adapted version of ASCII, since ASCII suited the needs of only the US and a few other countries. For example, Canada had its own version that supported French characters.

Many other countries developed variants of ASCII to include non-English letters (e.g. é, ñ, ß, Ł), currency symbols (e.g. £, ¥), etc. See also YUSCII (Yugoslavia).

It would share most characters in common, but assign other locally useful characters to several code points reserved for «national use». However, the four years that elapsed between the publication of ASCII-1963 and ISO’s first acceptance of an international recommendation during 1967^[57] caused ASCII’s choices for the national use characters to seem to be de facto standards for the world, causing confusion and incompatibility once other countries did begin to make their own assignments to these code points.

ISO/IEC 646, like ASCII, is a 7-bit character set. It does not make any additional codes available, so the same code points encoded different characters in different countries. Escape codes were defined to indicate which national variant applied to a piece of text, but they were rarely used, so it was often impossible to know what variant to work with and, therefore, which character a code represented, and in general, text-processing systems could cope with only one variant anyway.

Because the bracket and brace characters of ASCII were assigned to «national use» code points that were used for accented letters in other national variants of ISO/IEC 646, a German, French, or Swedish, etc. programmer using their national variant of ISO/IEC 646, rather than ASCII, had to write, and, thus, read, something such as

ä aÄiÜ = 'Ön'; ü

instead of

{ a[i] = 'n'; }

C trigraphs were created to solve this problem for ANSI C, although their late introduction and inconsistent implementation in compilers limited their use. Many programmers kept their computers on US-ASCII, so plain-text in Swedish, German etc. (for example, in e-mail or Usenet) contained «{, }» and similar variants in the middle of words, something those programmers got used to. For example, a Swedish programmer mailing another programmer asking if they should go for lunch, could get «N{ jag har sm|rg}sar» as the answer, which should be «Nä jag har smörgåsar» meaning «No I’ve got sandwiches».

In Japan and Korea, still as of the 2020s, a variation of ASCII is used, in which the backslash (5C hex) is rendered as ¥ (a Yen sign, in Japan) or ₩ (a Won sign, in Korea). This means that, for example, the file path C:UsersSmith is shown as C:¥Users¥Smith (in Japan) or C:₩Users₩Smith (in Korea).

In Europe, teletext character sets, which are variants of ASCII, are used for broadcast TV subtitles, defined by World System Teletext and broadcast using the DVB-TXT standard for embedding teletext into DVB transmissions.^[58] In the case that the subtitles were initially authored for teletext and converted, the derived subtitle formats are constrained to the same character sets.

8-bit codes[edit]

Eventually, as 8-, 16-, and 32-bit (and later 64-bit) computers began to replace 12-, 18-, and 36-bit computers as the norm, it became common to use an 8-bit byte to store each character in memory, providing an opportunity for extended, 8-bit relatives of ASCII. In most cases these developed as true extensions of ASCII, leaving the original character-mapping intact, but adding additional character definitions after the first 128 (i.e., 7-bit) characters.

Encodings include ISCII (India), VISCII (Vietnam). Although these encodings are sometimes referred to as ASCII, true ASCII is defined strictly only by the ANSI standard.

Most early home computer systems developed their own 8-bit character sets containing line-drawing and game glyphs, and often filled in some or all of the control characters from 0 to 31 with more graphics. Kaypro CP/M computers used the «upper» 128 characters for the Greek alphabet.

The PETSCII code Commodore International used for their 8-bit systems is probably unique among post-1970 codes in being based on ASCII-1963, instead of the more common ASCII-1967, such as found on the ZX Spectrum computer. Atari 8-bit computers and Galaksija computers also used ASCII variants.

The IBM PC defined code page 437, which replaced the control characters with graphic symbols such as smiley faces, and mapped additional graphic characters to the upper 128 positions. Operating systems such as DOS supported these code pages, and manufacturers of IBM PCs supported them in hardware. Digital Equipment Corporation developed the Multinational Character Set (DEC-MCS) for use in the popular VT220 terminal as one of the first extensions designed more for international languages than for block graphics. The Macintosh defined Mac OS Roman and Postscript defined another character set: both sets contained «international» letters, typographic symbols and punctuation marks instead of graphics, more like modern character sets.

The ISO/IEC 8859 standard (derived from the DEC-MCS) finally provided a standard that most systems copied (at least as accurately as they copied ASCII, but with many substitutions). A popular further extension designed by Microsoft, Windows-1252 (often mislabeled as ISO-8859-1), added the typographic punctuation marks needed for traditional text printing. ISO-8859-1, Windows-1252, and the original 7-bit ASCII were the most common character encodings until 2008 when UTF-8 became more common.^[54]

ISO/IEC 4873 introduced 32 additional control codes defined in the 80–9F hexadecimal range, as part of extending the 7-bit ASCII encoding to become an 8-bit system.^[59]

Unicode[edit]

Unicode and the ISO/IEC 10646 Universal Character Set (UCS) have a much wider array of characters and their various encoding forms have begun to supplant ISO/IEC 8859 and ASCII rapidly in many environments. While ASCII is limited to 128 characters, Unicode and the UCS support more characters by separating the concepts of unique identification (using natural numbers called code points) and encoding (to 8-, 16-, or 32-bit binary formats, called UTF-8, UTF-16, and UTF-32, respectively).

ASCII was incorporated into the Unicode (1991) character set as the first 128 symbols, so the 7-bit ASCII characters have the same numeric codes in both sets. This allows UTF-8 to be backward compatible with 7-bit ASCII, as a UTF-8 file containing only ASCII characters is identical to an ASCII file containing the same sequence of characters. Even more importantly, forward compatibility is ensured as software that recognizes only 7-bit ASCII characters as special and does not alter bytes with the highest bit set (as is often done to support 8-bit ASCII extensions such as ISO-8859-1) will preserve UTF-8 data unchanged.^[60]

See also[edit]

Notes[edit]

References[edit]

Further reading[edit]

• Bemer, Robert William (1960). «A Proposal for Character Code Compatibility». Communications of the ACM. 3 (2): 71–72. doi:10.1145/366959.366961. S2CID 9591147.
• Bemer, Robert William (2003-05-23). «The Babel of Codes Prior to ASCII: The 1960 Survey of Coded Character Sets: The Reasons for ASCII». Archived from the original on 2013-10-17. Retrieved 2016-05-09, from:
  • Bemer, Robert William (December 1960). «Survey of coded character representation». Communications of the ACM. 3 (12): 639–641. doi:10.1145/367487.367493. S2CID 21403172.
  • Smith, H. J.; Williams, F. A. (December 1960). «Survey of punched card codes». Communications of the ACM. 3 (12): 642. doi:10.1145/367487.367491.
• «American National Standard Code for Information Interchange | ANSI X3.4-1977» (PDF). National Institute for Standards. 1977. Archived (PDF) from the original on 2022-10-09. (facsimile, not machine readable)
• Robinson, G. S.; Cargill, C. (1996). «History and impact of computer standards». Computer. Vol. 29, no. 10. pp. 79–85. doi:10.1109/2.539725.
• Mullendore, Ralph Elvin (1964) [1963]. Ptak, John F. (ed.). «On the Early Development of ASCII – The History of ASCII». JF Ptak Science Books (published March 2012). Archived from the original on 2016-05-26. Retrieved 2016-05-26.

External links[edit]

• «C0 Controls and Basic Latin – Range: 0000–007F» (PDF). The Unicode Standard 8.0. Unicode, Inc. 2015 [1991]. Archived (PDF) from the original on 2016-05-26. Retrieved 2016-05-26.
• Fischer, Eric. «The Evolution of Character Codes, 1874–1968». CiteSeerX 10.1.1.96.678. [1]

Таблица кодов символов в современных компьютерах может быть использована любым юзером. Что это такое? И где найти подобный элемент? Как им пользоваться и для каких целей? Далее постараемся дать ответы на все перечисленные вопросы. Обычно таблицы символов позволяют печатать уникальные знаки в текстовых документов. Главное — знать, какими они бывают, а также где искать соответствующую информацию. Все намного проще, чем кажется.

Определение

Что такое таблица кодов символов? Это, как нетрудно догадаться, база данных. В ней пользователи могут увидеть сочетание числовых значений, при обработке которых в указанное место текста вставляется символ. Например, знак ♥ или ♫. На клавиатуре таких символов нет и быть не может.

Таблица символов помогает пользователям вставлять уникальные знаки в текстовые документы. Здесь можно увидеть кодировку элемента и способ его интерпретации.

Какими бывают

Кодировки символов — тип сочетания букв, цифр и знаков, которые после обработки операционной системой преобразовываются в знак. Они бывают разными.

Сегодня можно столкнуться с такими кодировками:

1. ASCII — способ печати специальных знаков, уникальные коды которых представлены цифрами. Это самый распространенный тип кодировки. Он был разработан в 1963 году в США. Кодировка является семибитной.
2. Windows-1251 — стандартная кодировка для русскоязычной «Виндовс». Она не слишком обширна и почти не пользуется спросом у юзеров.
3. Unicode — 16-битная кодировка для современных операционных систем. Она служит для представления символов и букв на любом языке. Используется современными пользователями наравне с ASCII.

Теперь понятно, какими бывают кодировки. Заострим внимание на первом и последнем варианте. Они пользуются самым большим спросом у современных пользователей ПК.

Где искать в Windows

Таблицы кодов символов по умолчанию вмонтированы в операционную систему «Виндовс». С их помощью юзер сможет печатать буквы и специальные знаки в любом текстовом редакторе или документе.

Для того, чтобы найти таблицу символов в «Виндовс», нужно:

1. Открыть пункт меню «Пуск».
2. Развернуть раздел «Все программы».
3. Выбрать папку «Стандартные»
4. Кликнуть по надписи «Служебные».
5. Заглянуть в приложение «Таблица символов».

Дело сделано. Теперь можно изучить все возможные знаки, которые только могут восприниматься операционной системой. Если дважды кликнуть по миниатюре того или иного символа, а затем щелкнуть по кнопке «Скопировать», соответствующий знак будет перенесен в буфер обмена. Из него можно выгрузить данные в текстовый документ.

Важно: в нижней части окна справа можно увидеть сочетание клавиш для быстрой печати выбранного элемента, а слева — «Юникод» для набора в тексте.

В MS Word

Таблицу кодов символов можно найти даже в текстовых редакторах. Рассмотрим алгоритм действий в MS Word. Это наиболее популярная и распространенная утилита для работы с документами в «Виндовс».

Открытие таблицы кодов символов осуществляется так:

1. Зайти в Word на компьютере. Можно открыть как пустой документ, так и с текстом.
2. Нажать в верхней части она по пункту «Вставка». Желательно развернуть весь список опций.
3. Навести курсор и щелкнуть ЛКМ по надписи «Специальный знак. «.

Вот и все. По центру экрана появится таблица символов. Здесь можно посмотреть таблицу ASCII, «Юникода» и не только. Для этого в нижней части окна в выпадающем списке нужно выбрать после надписи «из. » подходящую кодировку.

Вставка знака может осуществляться через двойной клик по элементу в таблице или путем активации кнопки «Вставить».

Способы обработки кода

Как мы уже говорили, таблица кодов символов помогает изучить цифро-алфавитный код того или иного символа. Как можно провести преобразование оных?

Как правило, «Юникод» обрабатывается следующим образом:

1. Пользователь пишет уникальный код подходящего символа. Обычно он начинается с U+.
2. Юзер нажимает сочетание клавиш Alt + X в текстовом редакторе.
3. Операционная система считывает код, после чего на месте записи появляется специальный знак.

Коды обрабатываются по одному. Это крайне важно. ASCII обрабатываются аналогичным образом.

Некоторые символы можно напечатать при помощи кнопки Alt. Обычно ее нужно зажать, а затем на цифирной панели клавиатуры набрать подходящий код. В этом случае придется заранее активировать режим Num Lock.

Примечание: Мы стараемся как можно оперативнее обеспечивать вас актуальными справочными материалами на вашем языке. Эта страница переведена автоматически, поэтому ее текст может содержать неточности и грамматические ошибки. Для нас важно, чтобы эта статья была вам полезна. Просим вас уделить пару секунд и сообщить, помогла ли она вам, с помощью кнопок внизу страницы. Для удобства также приводим ссылку на оригинал (на английском языке).

С помощью кодировок символов ASCII и Юникода можно хранить данные на компьютере и обмениваться ими с другими компьютерами и программами. Ниже перечислены часто используемые латинские символы ASCII и Юникода. Наборы символов Юникода, отличные от латинских, можно посмотреть в соответствующих таблицах, упорядоченных по наборам.

В этой статье

Вставка символа ASCII или Юникода в документ

Если вам нужно ввести только несколько специальных знаков или символов, можно использовать таблицу символов или сочетания клавиш. Список символов ASCII см. в следующих таблицах или статье Вставка букв национальных алфавитов с помощью сочетаний клавиш.

В многих языках есть символы, которые не удалось уместить в расширенный набор ACSII (256 символов). Поэтому существуют вариации наборов ASCII и Юникода с региональными знаками и символами (см. таблицы символов Юникода, упорядоченные по наборам).

Если у вас возникают проблемы с вводом кода необходимого символа, попробуйте использовать таблицу символов.

Вставка символов ASCII

Чтобы вставить символ ASCII, нажмите и удерживайте клавишу ALT, вводя код символа. Например, чтобы вставить символ градуса (º), нажмите и удерживайте клавишу ALT, затем введите 0176 на цифровой клавиатуре.

Для ввода чисел используйте цифровую клавиатуру, а не цифры на основной клавиатуре. Если на цифровой клавиатуре необходимо ввести цифры, убедитесь, что включен индикатор NUM LOCK.

Вставка символов Юникода

Чтобы вставить символ Юникода, введите код символа, затем последовательно нажмите клавиши ALT и X. Например, чтобы вставить символ доллара ($), введите 0024 и последовательно нажмите клавиши ALT и X. Все коды символов Юникода см. в таблицах символов Юникода, упорядоченных по наборам.

Важно: Некоторые программы Microsoft Office, например PowerPoint и InfoPath, не поддерживают преобразование кодов Юникода в символы. Если вам необходимо вставить символ Юникода в одной из таких программ, используйте таблицу символов.

Если после нажатия клавиш ALT+X отображается неправильный символ Юникода, выберите правильный код, а затем снова нажмите ALT+X.

Кроме того, перед кодом следует ввести «U+». Например, если ввести «1U+B5» и нажать клавиши ALT+X, отобразится текст «1µ», а если ввести «1B5» и нажать клавиши ALT+X, отобразится символ «Ƶ».

Использование таблицы символов

Таблица символов — это программа, встроенная в Microsoft Windows, которая позволяет просматривать символы, доступные для выбранного шрифта.

С помощью таблицы символов можно копировать отдельные символы или группу символов в буфер обмена и вставлять их в любую программу, поддерживающую отображение этих символов. Открытие таблицы символов

В Windows 10 Введите слово «символ» в поле поиска на панели задач и выберите таблицу символов в результатах поиска.

В Windows 8 Введите слово «символ» на начальном экране и выберите таблицу символов в результатах поиска.

В Windows 7 нажмите кнопку Пуск, последовательно выберите Все программы, Стандартные, Служебные и щелкните Таблица символов.

Символы группируются по шрифту. Щелкните список шрифтов, чтобы выбрать подходящий набор символов. Чтобы выбрать символ, щелкните его, затем нажмите кнопку Выбрать. Чтобы вставить символ, щелкните правой кнопкой мыши нужное место в документе и выберите Вставить.

Office 365, AD, Active Directory, Sharepoint, C#, Powershell. Технические статьи и заметки.

Word. Библиотека значков или как вставить забавный рисунок в текст документа

Дано: Word 2016 (обновляемый по подписке Office 365).
Задача: добавить на страницу рисунок (значок) из готовой коллекции рисунков.

Не так давно в Word появилась бесплатная коллекция значков, которые можно вставить в документ.
Значков более 500 штук по разным тематикам.
Для деловых документов, можно использовать бизнес-значки, значки с людьми, с техникой (компьютеры, принтеры), значки связи и аналитики и т.п.
Для оформления праздничных поздравлений есть также специальные значки.
Имеются медицинские и спортивные значки.

Как вставить значок в документ:
1) Щелкаем в нужное место в документе
2) Затем на ленте вкладка «Вставка»
3) Группа значков «Иллюстрации»
4) Кнопка «Значки»

Далее стиль значка можно менять: изменить цвет, размер, сделать его контурным, перевернуть и так далее. Для этого:
1) Щелкаем на рисунке
2) На ленте вкладка «Формат»
3) Группа кнопок «Стили рисунка»
4) Выбираем нужный стиль

Но помните, что вставить за раз можно не более 50 штук. Чтобы вставить больше, нужно сначала выделить 50 и вставить, затем снова открыть окно вставки значков, снова выделить нужное количество и вставить, и так повторить столько раз, сколько требуется значков.

Далее привожу примеры имеющихся значков.

• Значки «Люди»
• Значки на тему «Техника и электроника»
• Значки на тему «Связь»
• Значки на тему «Бизнес»
• Значки на тему «Аналитика»

• Значки на тему «Коммерция»
• Значки на тему «Образование»
• Значки на тему «Искусство»
• Значки на тему «Праздник»
• Значки «Лица» (смайлы)

• Значки на тему «Знаки и символы» (любовь, руки, предупреждения)
• Значки «Стрелки»
• Значки на тему «Интерфейс»
• Значки на тему «Природа» (отдых, путешествия)
• Значки на тему «Животные» (дикие, домашние)

• Значки на тему «Еда и напитки»
• Значки на тему «Погода» (времена года)
• Значки на тему «Местоположение» (карты, указатели)
• Значки на тему «Транспорт»
• Значки на тему «Здания» (дома)

• Значки на тему «Спорт» (спортивный инвентарь)
• Значки на тему «Безопасность и правосудие» (юридические)
• Значки на тему «Медицина»
• Значки на тему «Инструменты, строительство»
• Значки на тему «Дом» (мебель, вещи)
• Значки на тему «Одежда»

While a Program, as we all know, is, A set of instructions that specify the operations, operands, and the sequence by which processing has to occur. An instruction code is a group of bits that tells the computer to perform a specific operation part.

Instruction Code: Operation Code

The operation code of an instruction is a group of bits that define operations such as add, subtract, multiply, shift and compliment. The number of bits required for the operation code depends upon the total number of operations available on the computer. The operation code must consist of at least n bits for a given 2^n operations. The operation part of an instruction code specifies the operation to be performed.

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Instruction Code: Register Part

The operation must be performed on the data stored in registers. An instruction code therefore specifies not only operations to be performed but also the registers where the operands(data) will be found as well as the registers where the result has to be stored.

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Stored Program Organisation

The simplest way to organize a computer is to have Processor Register and instruction code with two parts. The first part specifies the operation to be performed and second specifies an address. The memory address tells where the operand in memory will be found.

Instructions are stored in one section of memory and data in another.

Computers with a single processor register is known as Accumulator (AC). The operation is performed with the memory operand and the content of AC.

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Common Bus System

The basic computer has 8 registers, a memory unit and a control unit. Paths must be provided to transfer data from one register to another. An efficient method for transferring data in a system is to use a Common Bus System. The output of registers and memory are connected to the common bus.

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Load(LD)

The lines from the common bus are connected to the inputs of each register and data inputs of memory. The particular register whose LD input is enabled receives the data from the bus during the next clock pulse transition.

Before studying about instruction formats lets first study about the operand address parts.

When the 2nd part of an instruction code specifies the operand, the instruction is said to have immediate operand. And when the 2nd part of the instruction code specifies the address of an operand, the instruction is said to have a direct address. And in indirect address, the 2nd part of instruction code, specifies the address of a memory word in which the address of the operand is found.

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Computer Instructions

The basic computer has three instruction code formats. The Operation code (opcode) part of the instruction contains 3 bits and remaining 13 bits depends upon the operation code encountered.

There are three types of formats:

1. Memory Reference Instruction

It uses 12 bits to specify the address and 1 bit to specify the addressing mode (I). I is equal to 0 for direct address and 1 for indirect address.

2. Register Reference Instruction

These instructions are recognized by the opcode 111 with a 0 in the left most bit of instruction. The other 12 bits specify the operation to be executed.

3. Input-Output Instruction

These instructions are recognized by the operation code 111 with a 1 in the left most bit of instruction. The remaining 12 bits are used to specify the input-output operation.

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Format of Instruction

The format of an instruction is depicted in a rectangular box symbolizing the bits of an instruction. Basic fields of an instruction format are given below:

1. An operation code field that specifies the operation to be performed.
2. An address field that designates the memory address or register.
3. A mode field that specifies the way the operand of effective address is determined.

Computers may have instructions of different lengths containing varying number of addresses. The number of address field in the instruction format depends upon the internal organization of its registers.

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