The American Standard Code for Information Interchange is a code that was invented late in the first decade of the Rock-n-Roll era in order to facilitate the electronic storage and distribution of textual data. The ASCII code associates each of a limited number of graphic characters (a letter, digit, or special symbol) and special commands with a number. ASCII is not the only method of storing and communicating text data on electronic media, but it has some significant advantages over other methods, which include

1. it is a standard code, understood throughout the world,
2. it is compact (ASCII documents require less space for storage than most other formats), and
3. it facilitates searches for content.

Computers store many text documents as files, which are actually just sequences of numbers. The numbers get into the computer by way of a human interface device, such as a keyboard, which translates the graphic characters (of the keys) into the numbers that the computer understands. These sequences of numbers are then easily transfered from one computer to another and to other human interface devices, such as display screens and printers, which translate the numbers back into graphic characters.

ASCII can be divided into two parts, the first part of the ASCII set is a representation of some special commands that computers use to communicate with each other and with other electronic devices. The commands are:

ASCII Commands

VALUE	COMMAND	VALUE	COMMAND	VALUE	COMMAND
0	NUL	1	SOH	2	STX
3	ETX	4	EOT	5	ENQ
6	ACK	7	BEL	8	BS
9	HT	10	LF	11	VT
12	FF	13	CR	14	SO
15	SI	16	DLE	17	DC1
18	DC2	19	DC3	20	DC4
21	NAK	22	SYN	23	ETB
24	CAN	25	EM	26	SUB
27	ESC	28	FS	29	GS
30	RS	31	US	32	SP

The second part of the ASCII set is a translation map for graphic characters.

ASCII Graphics

VALUE	GRAPHIC	VALUE	GRAPHIC	VALUE	GRAPHIC
33	!	34	"	35	#
36	$	37	%	38	&
39	'	40	(	41	)
42	*	43	+	44	,
45	-	46	.	47	/
48	0	49	1	50	2
51	3	52	4	53	5
54	6	55	7	56	8
57	9	58	:	59	;
60	<	61	=	62	>
63	?	64	@	65	A
66	B	67	C	68	D
69	E	70	F	71	G
72	H	73	I	74	J
75	K	76	L	77	M
78	N	79	O	80	P
81	Q	82	R	83	S
84	T	85	U	86	V
87	W	88	X	89	Y
90	Z	91	[	92	\
93	]	94	^	95	_
96	`	97	a	98	b
99	c	100	d	101	e
102	f	103	g	104	h
105	i	106	j	107	k
108	l	109	m	110	n
111	o	112	p	113	q
114	r	115	s	116	t
117	u	118	v	119	w
120	x	121	y	122	z
123	{	124	|	125	}
126	~

The last element of the ASCII set really belongs in the first group, since it is also a command.

VALUE	COMMAND
127	DEL

ASCII is a subset of ISO-8859.

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