What is ASCII (American Standard Code for Information Interchange)?

The ASCII (American Standard Code for Information Interchange) is the model or character model to be used during information exchange based on the Latin alphabet used in modern English and other western languages.

What is ASCII (American Standard Code for Information Interchange)?

ASCII History and Computer Codes

The ASCII code was developed in the telegraph field and was first used as a teleprint code that is commercially supported by Bell’s data services.

Bell had planned to use a six-bit code derived from Fieldata, which added punctuation and lowercase letters to the old Baudot teleprinting code, but was persuaded to join the ASA (American Standards Agency) subcommittee, which began developing the ASCII code.

Baudot automated the sending and receiving of telegram messages and received many features from the Morse code. However, unlike the Morse code, Baudot used fixed-length codes.

Compared to the early telegram codes, the code proposed by Bell and ASA resulted in a more convenient rearrangement to add additional features such as lists and escape sequences.

ASA, which will later become the ANSI (American National Standards Institute), first published the code ASCII in 1963.

In ASCII, published in 1963, there was an arrow pointing up (↑) instead of circumflex (^) and an arrow pointing left instead of underscore (_).

The 1967 version added lowercase letters, changed the names of some control codes, and two control codes moved ACK and ESC from the lowercase region to the control code region.

ASCII has been updated accordingly and published as ANSI X3.4-1968, ANSI X3.4-1977, and finally ANSI X3.4-1986.

Other standardization agencies have published character data that are the same as ASCII. Although they are only defined by ASA/ANSI standards, they are often called ASCII.

The ECMA (European Computer Manufacturers Association) released its publications of the ASCII clone ECMA-6 in 1965, 1967, 1970, 1973, 1983, and 1991. The 1991 version is the same as ANSI X3.4-1986.

ISO (International Organization for Standardization) published the ISO 646 product in 1967, 1972, 1983, and 1991.

Specifically, “ISO 646: 1972” created a country-specific set of versions where punctuation was replaced with non-English characters. ISO/IEC 646: 1991 International Reference Edition is the same as in ANSI X3.4-1986.

ITU (International Telecommunication Union) published ANSI X3.4-1986, ITU Recommendation T.50 in 1992. In the early 1970s, it released a version as “CCITT Recommendation V.3”.

DIN published a version of ASCII in 1974 as standard DIN 66003.

The Internet Engineering Working Group (IETF) released a version as RFC 20 in 1969, and with the release of RFC 1345 in 1992, it created the standard version for the Internet-based on ANSI X3.4-1986.

The IBM version of ANSI X3.4-1986 has been published in the IBM technical literature as code page 367.

ASCII Code

A computer’s memory stores all information digitally. There is no way to save characters directly. Each character has an equivalent digital code. This digital data is called the ASCII and represents characters using 7 bits.

Codes from 0 to 31 are not used for characters. These are called control characters because they are used for actions such as Carriage Return (CR) or Ring (BEL). Codes 65 to 90 represent uppercase letters, and 97 to 122 codes represent the lower case. If we change the 6th bit, it is equivalent to adding 32 to the code in decimal.

Control Characters

ASCII was not originally developed to carry printable information. It was developed to store the first 32 codes for control character codes to control devices using the same array or provide meta-information about data streams stored on the tape.

For example, character 10 represents the line feed function and character 8 represents the backspace key.

Control characters that do not contain carriage return, line feed, or white spaces are called control characters without spaces.

It does not define any mechanism, such as profit margin languages, address page, and other schemes such as document layout and format, to define the structure or appearance of text in a document, except for control characters that specify the basic line-oriented format.

The original standard used only brief descriptive statements for each control character. This uncertainty is sometimes slightly different from the data flow in a character’s terminal connection, sometimes it was deliberate when used accidentally.

Printable Characters

Code 32 (space character) specifies the space between words produced by a keyboard spacer. The space character is treated as an invisible graphic instead of the control character.

Codes 33 to 126, known as printable characters, represent letters, numbers, punctuation, and some miscellaneous symbols.

Seven-bit ASCII provided seven national characters, and if combined hardware and software allows, you can use extreme strokes to simulate some additional international characters in such a scenario.

It supports ASCII art, a minority artistic discipline that involves creating images using printable characters.

The effect obtained is compared with point techniques, since images produced by this technique are generally appreciated in more detail when viewed from a distance.

ASCII art began as an experimental art but soon became popular as a resource for representing images in non-graphic media such as teletypes, terminals, emails or some printers.

Although you can create ASCII art manually using a text editor, you can automatically convert images and videos to ASCII using software such as the popular Aalib library.

Aalib is supported by some graphic design programs, games, and video players.

Extended Table

   ASCII Control Characters Table (0-31)

DEC
OCT
HEX
BIN
Symbol
HTML Number
Description
0
0
0
0
NUL
�
Null char
1
1
1
1
SOH

Start of Heading
2
2
2
10
STX

Start of Text
3
3
3
11
ETX

End of Text
4
4
4
100
EOT

End of Transmission
5
5
5
101
ENQ

Enquiry
6
6
6
110
ACK

Acknowledgment
7
7
7
111
BEL

Bell
8
10
8
1000
BS

Back Space
9
11
9
1001
HT
	
Horizontal Tab
10
12
0A
1010
LF


Line Feed
11
13
0B
1011
VT

Vertical Tab
12
14
0C
1100
FF

Form Feed
13
15
0D
1101
CR

Carriage Return
14
16
0E
1110
SO

Shift Out / X-On
15
17
0F
1111
SI

Shift In / X-Off
16
20
10
10000
DLE

Data Line Escape
17
21
11
10001
DC1

Device Control 1 (oft. XON)
18
22
12
10010
DC2

Device Control 2
19
23
13
10011
DC3

Device Control 3 (oft. XOFF)
20
24
14
10100
DC4

Device Control 4
21
25
15
10101
NAK

Negative Acknowledgement
22
26
16
10110
SYN

Synchronous Idle
23
27
17
10111
ETB

End of Transmit Block
24
30
18
11000
CAN

Cancel
25
31
19
11001
EM

End of Medium
26
32
1A
11010
SUB

Substitute
27
33
1B
11011
ESC

Escape
28
34
1C
11100
FS

File Separator
29
35
1D
11101
GS

Group Separator
30
36
1E
11110
RS

Record Separator
31
37
1F
11111
US

Unit Separator

   ASCII Printable Characters Table (32-127)

DEC
OCT
HEX
BIN
Symbol
HTML Number
HTML Name
Description
32
40
20
100000
 
Space
33
41
21
100001
!
!
Exclamation mark
34
42
22
100010
"
"
Double quotes (or speech marks)
35
43
23
100011
#
#
Number
36
44
24
100100
$
$
Dollar
37
45
25
100101
%
%
Per cent sign
38
46
26
100110
&
&
&
Ampersand
39
47
27
100111
'
Single quote
40
50
28
101000
(
(
Open parenthesis (or open bracket)
41
51
29
101001
)
)
Close parenthesis (or close bracket)
42
52
2A
101010
*
*
Asterisk
43
53
2B
101011
+
+
Plus
44
54
2C
101100
,
,
Comma
45
55
2D
101101
-
Hyphen
46
56
2E
101110
.
.
Period, dot or full stop
47
57
2F
101111
/
/
Slash or divide
48
60
30
110000
0
0
Zero
49
61
31
110001
1
1
One
50
62
32
110010
2
2
Two
51
63
33
110011
3
3
Three
52
64
34
110100
4
4
Four
53
65
35
110101
5
5
Five
54
66
36
110110
6
6
Six
55
67
37
110111
7
7
Seven
56
70
38
111000
8
8
Eight
57
71
39
111001
9
9
Nine
58
72
3A
111010
:
:
Colon
59
73
3B
111011
;
&#59;
Semicolon
60
74
3C
111100
<
&#60;
&lt;
Less than (or open angled bracket)
61
75
3D
111101
=
&#61;
Equals
62
76
3E
111110
>
&#62;
&gt;
Greater than (or close angled bracket)
63
77
3F
111111
?
&#63;
Question mark
64
100
40
1000000
@
&#64;
At symbol
65
101
41
1000001
A
&#65;
Uppercase A
66
102
42
1000010
B
&#66;
Uppercase B
67
103
43
1000011
C
&#67;
Uppercase C
68
104
44
1000100
D
&#68;
Uppercase D
69
105
45
1000101
E
&#69;
Uppercase E
70
106
46
1000110
F
&#70;
Uppercase F
71
107
47
1000111
G
&#71;
Uppercase G
72
110
48
1001000
H
&#72;
Uppercase H
73
111
49
1001001
I
&#73;
Uppercase I
74
112
4A
1001010
J
&#74;
Uppercase J
75
113
4B
1001011
K
&#75;
Uppercase K
76
114
4C
1001100
L
&#76;
Uppercase L
77
115
4D
1001101
M
&#77;
Uppercase M
78
116
4E
1001110
N
&#78;
Uppercase N
79
117
4F
1001111
O
&#79;
Uppercase O
80
120
50
1010000
P
&#80;
Uppercase P
81
121
51
1010001
Q
&#81;
Uppercase Q
82
122
52
1010010
R
&#82;
Uppercase R
83
123
53
1010011
S
&#83;
Uppercase S
84
124
54
1010100
T
&#84;
Uppercase T
85
125
55
1010101
U
&#85;
Uppercase U
86
126
56
1010110
V
&#86;
Uppercase V
87
127
57
1010111
W
&#87;
Uppercase W
88
130
58
1011000
X
&#88;
Uppercase X
89
131
59
1011001
Y
&#89;
Uppercase Y
90
132
5A
1011010
Z
&#90;
Uppercase Z
91
133
5B
1011011
[
&#91;
Opening bracket
92
134
5C
1011100
\
&#92;
Backslash
93
135
5D
1011101
]
&#93;
Closing bracket
94
136
5E
1011110
^
&#94;
Caret – circumflex
95
137
5F
1011111
_
&#95;
Underscore
96
140
60
1100000
`
&#96;
Grave accent
97
141
61
1100001
a
&#97;
Lowercase a
98
142
62
1100010
b
&#98;
Lowercase b
99
143
63
1100011
c
&#99;
Lowercase c
100
144
64
1100100
d
&#100;
Lowercase d
101
145
65
1100101
e
&#101;
Lowercase e
102
146
66
1100110
f
&#102;
Lowercase f
103
147
67
1100111
g
&#103;
Lowercase g
104
150
68
1101000
h
&#104;
Lowercase h
105
151
69
1101001
i
&#105;
Lowercase i
106
152
6A
1101010
j
&#106;
Lowercase j
107
153
6B
1101011
k
&#107;
Lowercase k
108
154
6C
1101100
l
&#108;
Lowercase l
109
155
6D
1101101
m
&#109;
Lowercase m
110
156
6E
1101110
n
&#110;
Lowercase n
111
157
6F
1101111
o
&#111;
Lowercase o
112
160
70
1110000
p
&#112;
Lowercase p
113
161
71
1110001
q
&#113;
Lowercase q
114
162
72
1110010
r
&#114;
Lowercase r
115
163
73
1110011
s
&#115;
Lowercase s
116
164
74
1110100
t
&#116;
Lowercase t
117
165
75
1110101
u
&#117;
Lowercase u
118
166
76
1110110
v
&#118;
Lowercase v
119
167
77
1110111
w
&#119;
Lowercase w
120
170
78
1111000
x
&#120;
Lowercase x
121
171
79
1111001
y
&#121;
Lowercase y
122
172
7A
1111010
z
&#122;
Lowercase z
123
173
7B
1111011
{
&#123;
Opening brace
124
174
7C
1111100
|
&#124;
Vertical bar
125
175
7D
1111101
}
&#125;
Closing brace
126
176
7E
1111110
~
&#126;
Equivalency sign – tilde
127
177
7F
1111111
&#127;
Delete

   Extended ASCII Codes Table (128-255)

DEC
OCT
HEX
BIN
Symbol
HTML Number
HTML Name
Description
128
200
80
10000000
&#128;
&euro;
Euro sign
129
201
81
10000001
130
202
82
10000010
&#130;
&sbquo;
Single low-9 quotation mark
131
203
83
10000011
ƒ
&#131;
&fnof;
Latin small letter f with hook
132
204
84
10000100
&#132;
&bdquo;
Double low-9 quotation mark
133
205
85
10000101
&#133;
&hellip;
Horizontal ellipsis
134
206
86
10000110
&#134;
&dagger;
Dagger
135
207
87
10000111
&#135;
&Dagger;
Double dagger
136
210
88
10001000
ˆ
&#136;
&circ;
Modifier letter circumflex accent
137
211
89
10001001
&#137;
&permil;
Per mille sign
138
212
8A
10001010
Š
&#138;
&Scaron;
Latin capital letter S with caron
139
213
8B
10001011
&#139;
&lsaquo;
Single left-pointing angle quotation
140
214
8C
10001100
Œ
&#140;
&OElig;
Latin capital ligature OE
141
215
8D
10001101
142
216
8E
10001110
Ž
&#142;
Latin capital letter Z with caron
143
217
8F
10001111
144
220
90
10010000
145
221
91
10010001
&#145;
&lsquo;
Left single quotation mark
146
222
92
10010010
&#146;
&rsquo;
Right single quotation mark
147
223
93
10010011
&#147;
&ldquo;
Left double quotation mark
148
224
94
10010100
&#148;
&rdquo;
Right double quotation mark
149
225
95
10010101
&#149;
&bull;
Bullet
150
226
96
10010110
&#150;
&ndash;
En dash
151
227
97
10010111
&#151;
&mdash;
Em dash
152
230
98
10011000
˜
&#152;
&tilde;
Small tilde
153
231
99
10011001
&#153;
&trade;
Trade mark sign
154
232
9A
10011010
š
&#154;
&scaron;
Latin small letter S with caron
155
233
9B
10011011
&#155;
&rsaquo;
Single right-pointing angle quotation mark
156
234
9C
10011100
œ
&#156;
&oelig;
Latin small ligature oe
157
235
9D
10011101
158
236
9E
10011110
ž
&#158;
Latin small letter z with caron
159
237
9F
10011111
Ÿ
&#159;
&Yuml;
Latin capital letter Y with diaeresis
160
240
A0
10100000
&#160;
&nbsp;
Non-breaking space
161
241
A1
10100001
¡
&#161;
&iexcl;
Inverted exclamation mark
162
242
A2
10100010
¢
&#162;
&cent;
Cent sign
163
243
A3
10100011
£
&#163;
&pound;
Pound sign
164
244
A4
10100100
¤
&#164;
&curren;
Currency sign
165
245
A5
10100101
¥
&#165;
&yen;
Yen sign
166
246
A6
10100110
¦
&#166;
&brvbar;
Pipe, Broken vertical bar
167
247
A7
10100111
§
&#167;
&sect;
Section sign
168
250
A8
10101000
¨
&#168;
&uml;
Spacing diaeresis – umlaut
169
251
A9
10101001
©
&#169;
&copy;
Copyright sign
170
252
AA
10101010
ª
&#170;
&ordf;
Feminine ordinal indicator
171
253
AB
10101011
«
&#171;
&laquo;
Left double angle quotes
172
254
AC
10101100
¬
&#172;
&not;
Not sign
173
255
AD
10101101
­
&#173;
&shy;
Soft hyphen
174
256
AE
10101110
®
&#174;
&reg;
Registered trade mark sign
175
257
AF
10101111
¯
&#175;
&macr;
Spacing macron – overline
176
260
B0
10110000
°
&#176;
&deg;
Degree sign
177
261
B1
10110001
±
&#177;
&plusmn;
Plus-or-minus sign
178
262
B2
10110010
²
&#178;
&sup2;
Superscript two – squared
179
263
B3
10110011
³
&#179;
&sup3;
Superscript three – cubed
180
264
B4
10110100
´
&#180;
&acute;
Acute accent – spacing acute
181
265
B5
10110101
µ
&#181;
&micro;
Micro sign
182
266
B6
10110110
&#182;
&para;
Pilcrow sign – paragraph sign
183
267
B7
10110111
·
&#183;
&middot;
Middle dot – Georgian comma
184
270
B8
10111000
¸
&#184;
&cedil;
Spacing cedilla
185
271
B9
10111001
¹
&#185;
&sup1;
Superscript one
186
272
BA
10111010
º
&#186;
&ordm;
Masculine ordinal indicator
187
273
BB
10111011
»
&#187;
&raquo;
Right double angle quotes
188
274
BC
10111100
¼
&#188;
&frac14;
Fraction one quarter
189
275
BD
10111101
½
&#189;
&frac12;
Fraction one half
190
276
BE
10111110
¾
&#190;
&frac34;
Fraction three quarters
191
277
BF
10111111
¿
&#191;
&iquest;
Inverted question mark
192
300
C0
11000000
À
&#192;
&Agrave;
Latin capital letter A with grave
193
301
C1
11000001
Á
&#193;
&Aacute;
Latin capital letter A with acute
194
302
C2
11000010
Â
&#194;
&Acirc;
Latin capital letter A with circumflex
195
303
C3
11000011
Ã
&#195;
&Atilde;
Latin capital letter A with tilde
196
304
C4
11000100
Ä
&#196;
&Auml;
Latin capital letter A with diaeresis
197
305
C5
11000101
Å
&#197;
&Aring;
Latin capital letter A with ring above
198
306
C6
11000110
Æ
&#198;
&AElig;
Latin capital letter AE
199
307
C7
11000111
Ç
&#199;
&Ccedil;
Latin capital letter C with cedilla
200
310
C8
11001000
È
&#200;
&Egrave;
Latin capital letter E with grave
201
311
C9
11001001
É
&#201;
&Eacute;
Latin capital letter E with acute
202
312
CA
11001010
Ê
&#202;
&Ecirc;
Latin capital letter E with circumflex
203
313
CB
11001011
Ë
&#203;
&Euml;
Latin capital letter E with diaeresis
204
314
CC
11001100
Ì
&#204;
&Igrave;
Latin capital letter I with grave
205
315
CD
11001101
Í
&#205;
&Iacute;
Latin capital letter I with acute
206
316
CE
11001110
Î
&#206;
&Icirc;
Latin capital letter I with circumflex
207
317
CF
11001111
Ï
&#207;
&Iuml;
Latin capital letter I with diaeresis
208
320
D0
11010000
Ð
&#208;
&ETH;
Latin capital letter ETH
209
321
D1
11010001
Ñ
&#209;
&Ntilde;
Latin capital letter N with tilde
210
322
D2
11010010
Ò
&#210;
&Ograve;
Latin capital letter O with grave
211
323
D3
11010011
Ó
&#211;
&Oacute;
Latin capital letter O with acute
212
324
D4
11010100
Ô
&#212;
&Ocirc;
Latin capital letter O with circumflex
213
325
D5
11010101
Õ
&#213;
&Otilde;
Latin capital letter O with tilde
214
326
D6
11010110
Ö
&#214;
&Ouml;
Latin capital letter O with diaeresis
215
327
D7
11010111
×
&#215;
&times;
Multiplication sign
216
330
D8
11011000
Ø
&#216;
&Oslash;
Latin capital letter O with slash
217
331
D9
11011001
Ù
&#217;
&Ugrave;
Latin capital letter U with grave
218
332
DA
11011010
Ú
&#218;
&Uacute;
Latin capital letter U with acute
219
333
DB
11011011
Û
&#219;
&Ucirc;
Latin capital letter U with circumflex
220
334
DC
11011100
Ü
&#220;
&Uuml;
Latin capital letter U with diaeresis
221
335
DD
11011101
Ý
&#221;
&Yacute;
Latin capital letter Y with acute
222
336
DE
11011110
Þ
&#222;
&THORN;
Latin capital letter THORN
223
337
DF
11011111
ß
&#223;
&szlig;
Latin small letter sharp s – ess-zed
224
340
E0
11100000
à
&#224;
&agrave;
Latin small letter a with grave
225
341
E1
11100001
á
&#225;
&aacute;
Latin small letter a with acute
226
342
E2
11100010
â
&#226;
&acirc;
Latin small letter a with circumflex
227
343
E3
11100011
ã
&#227;
&atilde;
Latin small letter a with tilde
228
344
E4
11100100
ä
&#228;
&auml;
Latin small letter a with diaeresis
229
345
E5
11100101
å
&#229;
&aring;
Latin small letter a with ring above
230
346
E6
11100110
æ
&#230;
&aelig;
Latin small letter ae
231
347
E7
11100111
ç
&#231;
&ccedil;
Latin small letter c with cedilla
232
350
E8
11101000
è
&#232;
&egrave;
Latin small letter e with grave
233
351
E9
11101001
é
&#233;
&eacute;
Latin small letter e with acute
234
352
EA
11101010
ê
&#234;
&ecirc;
Latin small letter e with circumflex
235
353
EB
11101011
ë
&#235;
&euml;
Latin small letter e with diaeresis
236
354
EC
11101100
ì
&#236;
&igrave;
Latin small letter i with grave
237
355
ED
11101101
í
&#237;
&iacute;
Latin small letter i with acute
238
356
EE
11101110
î
&#238;
&icirc;
Latin small letter i with circumflex
239
357
EF
11101111
ï
&#239;
&iuml;
Latin small letter i with diaeresis
240
360
F0
11110000
ð
&#240;
&eth;
Latin small letter eth
241
361
F1
11110001
ñ
&#241;
&ntilde;
Latin small letter n with tilde
242
362
F2
11110010
ò
&#242;
&ograve;
Latin small letter o with grave
243
363
F3
11110011
ó
&#243;
&oacute;
Latin small letter o with acute
244
364
F4
11110100
ô
&#244;
&ocirc;
Latin small letter o with circumflex
245
365
F5
11110101
õ
&#245;
&otilde;
Latin small letter o with tilde
246
366
F6
11110110
ö
&#246;
&ouml;
Latin small letter o with diaeresis
247
367
F7
11110111
÷
&#247;
&divide;
Division sign
248
370
F8
11111000
ø
&#248;
&oslash;
Latin small letter o with slash
249
371
F9
11111001
ù
&#249;
&ugrave;
Latin small letter u with grave
250
372
FA
11111010
ú
&#250;
&uacute;
Latin small letter u with acute
251
373
FB
11111011
û
&#251;
&ucirc;
Latin small letter u with circumflex
252
374
FC
11111100
ü
&#252;
&uuml;
Latin small letter u with diaeresis
253
375
FD
11111101
ý
&#253;
&yacute;
Latin small letter y with acute
254
376
FE
11111110
þ
&#254;
&thorn;
Latin small letter thorn
255
377
FF
11111111
ÿ
&#255;
&yuml;
Latin small letter y with diaeresis

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