ASCII

A Problem: Can’t represent letters and symbols in binary

Solution: American Standard Code for Information Interchange (ASCII)

“AND” in ASCII

Let’s use ASCII to make the word AND (in all caps)

Letter	Decimal Value	1	2	4	8	16	32	64	128
A	65	1	0	0	0	0	0	1	0
N	78	0	1	1	1	0	0	1	0
D	68	0	0	1	0	0	0	1	0

Table of ASCII Characters and Their Decimal Values

Decimal Value	Letter/Number/Symbol	Description
0	NUL	Null
1	SOH	Start of Heading
2	STX	Start of Text
3	ETX	End of Text
4	EOT	End of Transmission
5	ENQ	Enquiry
6	ACK	Acknowledge
7	BEL	Bell
8	BS	Backspace
9	HT	Horizontal Tab
10	LF	NL Line Feed, New Line
11	VT	Vertical Tab
12	FF	NP Form Feed, New Page
13	CR	Carriage Return
14	SO	Shift Out
15	SI	Shift In
16	DLE	Data Link Escape
17	DC1	Device Control 1
18	DC2	Device Control 2
19	DC3	Device Control 3
20	DC4	Device Control 4
21	NAK	Negative Acknowledge
22	SYN	Synchronous Idle
23	ETB	End of Transmission Block
24	CAN	Cancel
25	EM	End of Medium
26	SUB	Substitute
27	ESC	Escape
28	FS	File Separator
29	GS	Group Separator
30	RS	Record Separator
31	US	Unit Separator
32	(Space)	Space
33	!	Exclamation Mark
34	”	Double Quote
35	#	Hash or Number
36	$	Dollar Sign
37	%	Percentage
38	&	Ampersand
39	’	Single Quote
40	(	Left Parenthesis
41	)	Right Parenthesis
42	*	Asterisk
43	+	Plus Sign
44	,	Comma
45	-	Minus Sign
46	.	Period
47	/	Slash
48	0	Zero
49	1	Number One
50	2	Number Two
51	3	Number Three
52	4	Number Four
53	5	Number Five
54	6	Number Six
55	7	Number Seven
56	8	Number Eight
57	9	Number Nine
58	:	Colon
59	;	Semicolon
60	<	Less Than
61	=	Equals Sign
62	>	Greater Than
63	?	Question Mark
64	@	At Sign
65	A	Upper Case Letter A
66	B	Upper Case Letter B
67	C	Upper Case Letter C
68	D	Upper Case Letter D
69	E	Upper Case Letter E
70	F	Upper Case Letter F
71	G	Upper Case Letter G
72	H	Upper Case Letter H
73	I	Upper Case Letter I
74	J	Upper Case Letter J
75	K	Upper Case Letter K
76	L	Upper Case Letter L
77	M	Upper Case Letter M
78	N	Upper Case Letter N
79	O	Upper Case Letter O
80	P	Upper Case Letter P
81	Q	Upper Case Letter Q
82	R	Upper Case Letter R
83	S	Upper Case Letter S
84	T	Upper Case Letter T
85	U	Upper Case Letter U
86	V	Upper Case Letter V
87	W	Upper Case Letter W
88	X	Upper Case Letter X
89	Y	Upper Case Letter Y
90	Z	Upper Case Letter Z
91	[	Left Square Bracket
92	\	Backslash
93	]	Right Square Bracket
94	^	Caret or Circumflex
95	_	Underscore
96	`	Grave Accent
97	a	Lower Case Letter a
98	b	Lower Case Letter b
99	c	Lower Case Letter c
100	d	Lower Case Letter d
101	e	Lower Case Letter e
102	f	Lower Case Letter f
103	g	Lower Case Letter g
104	h	Lower Case Letter h
105	i	Lower Case Letter i
106	j	Lower Case Letter j
107	k	Lower Case Letter k
108	l	Lower Case Letter l
109	m	Lower Case Letter m
110	n	Lower Case Letter n
111	o	Lower Case Letter o
112	p	Lower Case Letter p
113	q	Lower Case Letter q
114	r	Lower Case Letter r
115	s	Lower Case Letter s
116	t	Lower Case Letter t
117	u	Lower Case Letter u
118	v	Lower Case Letter v
119	w	Lower Case Letter w
120	x	Lower Case Letter x
121	y	Lower Case Letter y
122	z	Lower Case Letter z
123	{	Left Curly Bracket
124	|	Vertical Bar
125	}	Right Curly Bracket
126	~	Tilde
127	DEL	Delete