The above encoding scheme is ok but does not allow for symbols to be stored or different cased letters. The more symbols/letters we need to store the more binary bits we need to store it is. ASCii is a industry standard way of storing text and requires 7 bits to store it. Below is the ASCii table.

 

Character

ANSI

 

Character

ANSI

 

Character

ANSI

 Number 

 

 Number 

 

 Number 

' '

32

 

A

65

 

b

98

!

33

 

B

66

 

c

99

"

34

 

C

67

 

d

100

#

35

 

D

68

 

e

101

$

36

 

E

69

 

f

102

%

37

 

F

70

 

g

103

&

38

 

G

71

 

h

104

'

39

 

H

72

 

i

105

(

40

 

I

73

 

j

106

)

41

 

J

74

 

k

107

*

42

 

K

75

 

l

108

+

43

 

L

76

 

m

109

,

44

 

M

77

 

n

110

-

45

 

N

78

 

o

111

.

46

 

O

79

 

p

112

/

47

 

P

80

 

q

113

0

48

 

Q

81

 

r

114

1

49

 

R

82

 

s

115

2

50

 

S

83

 

t

116

3

51

 

T

84

 

u

117

4

52

 

U

85

 

v

118

5

53

 

V

86

 

w

119

6

54

 

W

87

 

x

120

7

55

 

X

88

 

y

121

8

56

 

Y

89

 

z

122

9

57

 

Z

90

 

{

123

:

58

 

[

91

 

|

124

;

59

 

\

92

 

}

125

<  

60

 

]

93

 

~

126

=

61

 

^

94

 

 

127

>  

62

 

_

95

 

 

 

?

63

 

`

96

 

 

 

@

64

 

a

97

 

 

 

Notice that letters start at 65 to 90 and also 97 to 122. This is so we can store both uppercase and lowercase letters. Punctuation and symbols get their own value. Finally single digit numbers get their own value. The reason why numbers are stored in this way is to allow numbers and text to be mixed together without having to continuously swap encoding schemes.

7 bits is difficult to store in a computer as they tend to work in bytes (8 bits). As such we use 8 bits to store each letter. This redundancy allows you to store extra symbols such as accents on letters etc.