ASCII stands for American Standard Code for Information Interchange.
Pronounced "as-kee," the adoption of the ASCII character coding scheme was
an important milestone in the history of the computing industry.
ASCII (American Standard Code for Information Interchange)
Something that computer programmers take for granted today, ASCII codes
were developed during the early 1960s as a standard that assigns numeric
values to letters, numbers, punctuation marks, and other characters.
The uppercase letter "A," for instance, is represented by the number 65,
while the lowercase letter "a" is represented by the number 97. The
number "0" is represented by the number 48, while the blank space
character is represented by the number 32. The first 32 numbers are
reserved for non-printable control codes such as the null character (0),
audible bell (07), backspace (08), horizontal tab (09), and form feed (12).
Before the development of ASCII, communication between different computers
was difficult or impossible. Each computer manufacturer used its own
digital coding scheme for representing characters. IBM, for example,
used a 6-bit character coding scheme derived from the binary coded decimal
(BCD) system of Hollerith-designed punch cards, while UNIVAC used a 6-bit
variant of the US Army's FIELDATA coding system. So in May, 1961,
Bob Bemer of IBM requested that
ANSI,
the American National Standards Institute, develop a standard coding
scheme to enable diverse computers to communicate with each other.
After lengthy debate, ASCII was published in 1963, shortly before the IBM
System/360 computer was released. In the interim, the IBM 360
development team had designed an extended BCD coding system (EBCDIC), and they unfortunately didn't have enough lead time to
modify the operating system and peripherals for ASCII prior to the
System/360's 1964 release. Many years later, in 1981, IBM
introduced their Personal Computer that used the ASCII coding standard,
and ASCII has now been widely adopted by most computer
manufacturers. Today, most personal computers and their peripherals
use ASCII characters.
Below, you will find a table listing the standard ASCII codes, as used
by computer programmers in the United States of America.
US ASCII Character Codes (000-063)
Binary
Hexa-
Char- acter
00000000
000
00
NUL
00000001
001
01
SOH
00000010
002
02
STX
00000011
003
03
ETX
00000100
004
04
EOT
00000101
005
05
ENQ
00000110
006
06
ACK
00000111
007
07
BEL
00001000
008
08
BS
00001001
009
09
HT
00001010
010
0A
LF
00001011
011
0B
VT
00001100
012
0C
FF
00001101
013
0D
CR
00001110
014
0E
SO
00001111
015
0F
SI
00010000
016
10
DLE
00010001
017
11
DC1
00010010
018
12
DC2
00010011
019
13
DC3
00010100
020
14
DC4
00010101
021
15
NAK
00010110
022
16
SYN
00010111
023
17
ETB
00011000
024
18
CAN
00011001
025
19
EM
00011010
026
1A
SUB
00011011
027
1B
ESC
00011100
028
1C
FS
00011101
029
1D
GS
00011110
030
1E
RS
00011111
031
1F
US
00100000
032
20
SP
00100001
033
21
!
00100010
034
22
"
00100011
035
23
#
00100100
036
24
$
00100101
037
25
%
00100110
038
26
&
00100111
039
27
'
00101000
040
28
(
00101001
041
29
)
00101010
042
2A
*
00101011
043
2B
+
00101100
044
2C
,
00101101
045
2D
-
00101110
046
2E
.
00101111
047
2F
/
00110000
048
30
0
00110001
049
31
1
00110010
050
32
2
00110011
051
33
3
00110100
052
34
4
00110101
053
35
5
00110110
054
36
6
00110111
055
37
7
00111000
056
38
8
00111001
057
39
9
00111010
058
3A
:
00111011
059
3B
;
00111100
060
3C
<
00111101
061
3D
=
00111110
062
3E
>
00111111
063
3F
?
US ASCII Character Codes (064-127)
Binary
Hexa-
Char- acter
01000000
064
40
@
01000001
065
41
A
01000010
066
42
B
01000011
067
43
C
01000100
068
44
D
01000101
069
45
E
01000110
070
46
F
01000111
071
47
G
01001000
072
48
H
01001001
073
49
I
01001010
074
4A
J
01001011
075
4B
K
01001100
076
4C
L
01001101
077
4D
M
01001110
078
4E
N
01001111
079
4F
O
01010000
080
50
P
01010001
081
51
Q
01010010
082
52
R
01010011
083
53
S
01010100
084
54
T
01010101
085
55
U
01010110
086
56
V
01010111
087
57
W
01011000
088
58
X
01011001
089
59
Y
01011010
090
5A
Z
01011011
091
5B
[
01011100
092
5C
\
01011101
093
5D
]
01011110
094
5E
^
01011111
095
5F
_
01100000
096
60
`
01100001
097
61
a
01100010
098
62
b
01100011
099
63
c
01100100
100
64
d
01100101
101
65
e
01100110
102
66
f
01100111
103
67
g
01101000
104
68
h
01101001
105
69
i
01101010
106
6A
j
01101011
107
6B
k
01101100
108
6C
l
01101101
109
6D
m
01101110
110
6E
n
01101111
111
6F
o
01110000
112
70
p
01110001
113
71
q
01110010
114
72
r
01110011
115
73
s
01110100
116
74
t
01110101
117
75
u
01110110
118
76
v
01110111
119
77
w
01111000
120
78
x
01111001
121
79
y
01111010
122
7A
z
01111011
123
7B
{
01111100
124
7C
|
01111101
125
7D
}
01111110
126
7E
~
01111111
127
7F
DEL
Related Codes And Software Sites
HTML Colors - Hypertext Markup Language color codes.
ASCII (American Standard Code for Information Interchange)
Before the development of ASCII, communication between different computers
was difficult or impossible. Each computer manufacturer used its own
digital coding scheme for representing characters. IBM, for example,
used a 6-bit character coding scheme derived from the binary coded decimal
(BCD) system of Hollerith-designed punch cards, while UNIVAC used a 6-bit
variant of the US Army's FIELDATA coding system. So in May, 1961,
Bob Bemer of IBM requested that
ANSI,
the American National Standards Institute, develop a standard coding
scheme to enable diverse computers to communicate with each other.
After lengthy debate, ASCII was published in 1963, shortly before the IBM
System/360 computer was released. In the interim, the IBM 360
development team had designed an extended BCD coding system (EBCDIC), and they unfortunately didn't have enough lead time to
modify the operating system and peripherals for ASCII prior to the
System/360's 1964 release. Many years later, in 1981, IBM
introduced their Personal Computer that used the ASCII coding standard,
and ASCII has now been widely adopted by most computer
manufacturers. Today, most personal computers and their peripherals
use ASCII characters.