What is the largest ascii code?

The largest ascii code is 127. ASCII code is the American Standard Code for Information Interchange, a computer coding system based on the Latin alphabet, mainly used to display modern English and other Western European languages. The standard ASCII code uses 7 binary bits to represent one character, with a total of 128 codes; 0 to 31 and 127 are control characters or special communication characters (the rest are displayable characters), 32 to 126 are characters, and 65 to 90 are There are 26 uppercase English letters, numbers 97 to 122 are lowercase English letters, and the rest are some punctuation marks, arithmetic symbols, etc.

The operating environment of this tutorial: Windows 7 system, Dell G3 computer.

The largest ascii code is 127.

Because the computer can only directly accept, store and process binary numbers. Numerical information can be represented by binary numbers, while non-numeric information must be represented by binary coding. Coding refers to using a small number of basic symbols to combine according to certain rules to represent a large amount of complex and diverse information. Generally speaking, which words and symbols need to be represented by binary codes depends on which words and symbols we require the computer to "recognize". In order to store text and symbols in the computer, the text and symbols must be converted into binary numbers according to the prescribed encoding. At present, computers generally use the ASCII code (American Standard Code for Information Interchange) specified by the International Organization for Standardization to represent English letters and symbols.

ASCII (American Standard Code for Information Interchange): The American Standard Code for Information Interchange is a computer coding system based on the Latin alphabet, mainly used to display modern English and other Western European languages.

Standard ASCII code, usually also called 7-bit code, consists of 7-bit binary code, the highest bit is 0, its range is expressed as 00000000~01111111 in binary, and 0~127 in decimal, a total of 128 types (2 to the 7th power), each code represents a basic symbol, that is to say, up to 128 basic symbols can be represented using ASCII codes.

The standard ASCII code is composed of a binary code consisting of a group of 3 digits and a group of 4 digits. A group of 3 digits constitutes 7 columns, and a group of 4 digits constitutes 15 rows. The behavior is the lower 4 digits and the column is the upper 3 digits. According to the column and row positions of letters and numbers, an ASCII code can be fixed. For example: the letter A is located in column 4 and row 1, that is, the ASCII code is 01000001BCD. Similarly, given a 7-bit ASCII, a corresponding number, letter or symbol can be immediately found.

The expression of ascii code

• 0~31 and 127 (33 in total) are control characters or special communication characters (the rest are optional Display characters)

  Such as control characters: LF (line feed), CR (carriage return), FF (page feed), DEL (delete), BS (backspace), BEL (ring), etc.;

  Special characters for communication: SOH (head of text), EOT (end of text), ACK (confirmation), etc.;

  ASCII values ​​of 8, 9, 10 and 13 are converted to backspace and tab respectively. , line feed and carriage return characters. They do not have a specific graphic display, but will have different effects on text display depending on different applications [1] .

• 32~126 (95 in total) are characters (32 is a space), of which 48~57 are ten Arabic numerals from 0 to 9.

• 65~90 are 26 uppercase English letters, 97~122 are 26 lowercase English letters, and the rest are some punctuation marks, arithmetic symbols, etc.

Also note that in standard ASCII, its highest bit (b7) is used as a parity bit. The so-called parity check refers to a method used to check whether errors occur during code transmission. It is generally divided into two types: odd check and even check. Odd parity rules: the number of 1's in a byte of the correct code must be an odd number. If it is not an odd number, add 1 to the highest bit b7; even parity rules: the number of 1's in a byte of the correct code must be an even number. , if it is not an even number, add 1 to the highest bit b7.

The ASCII code table is as follows:

##0000 01000440000 01010000 01100000 01110000 1000011 90x09HT (horizontal tab)Horizontal tab012##0000 1011013##0x0C0000 11010000 11100000 11110001 0000##DC2 (device control 2)Device Control 2##0230001 0100##210x15 NAK (negative acknowledge)Reject to accept22##230x17 ETB (end of trans. block)End of Transmission Block0001 1000030240x18CAN (cancel)Cancel##0001 10010001 1010##0x1DGS (group separator)Group separator036300x1E037##0010 00000400010 0001##042340x22"Double quotes0010 0011043350x230010 0100044360x24$Dollar sign##0010 0101##046047##0010 1000 050420x2A*##43##055450x2D-0010 1110060480x300Characters 0061490x311Character 1062##Characters 4##53##0011 0110066540011 011106755##0011 1001071570x399Characters 90011 1010072580x3A:Colon##0011 1011##620x3E> is greater than 077630x3F010001010102##0x45E##0100 01100107710x47G0110##0100 10010111##0x4CL##0100 1101 011577##0117790x4FO0101 0000##0101 00010101 00100101 0011##0x54TCapital letter T0125##0101 011001260101 01110127 0101 10000130##0x58X##0101 11000134920x5C\Backslash##0101 11010101 1110 0101 11110140 960x60`Open single quotation mark01410142##99##0x65elower case e##0110 0110##lower case g01501040x68h##0110 10010151##0x69ilowercase i1060x6A0110 101101531070110 1100##0x6Cllower case l0x6D##0110 1110##0x70plower case p##0111 0001##0111 00100111 0011 0111 0100##0x74tlower case t0165##0111 0110##lower case x1210x79ylower case Letter y##0x7B{Open brackets##0111 1100##0111 110101771270x7F DEL (delete)Delete Column!

ASCII table

Bin (binary)	Oct (octal)	Dec (decimal)	Hex (Hex)	Abbreviation/Character	Explanation
0000 0000	00	0	0x00	NUL(null)	##null character
0000 0001	01	1	0x01	SOH(start of headline)	Start of headline
0000 0010	02	2	0x02	STX (start of text)	Start of text
0000 0011	03	3	##0x03	ETX (end of text)	End of text
		##0x04	EOT (end of transmission)	Transmission End
05	5	0x05	ENQ (enquiry)	Request
##06	6	0x06	ACK (acknowledge)	Receive notification
07	7	0x07	BEL (bell)	Bell
010	8	##0x08	BS (backspace)	Backspace	##0000 1001
					##0000 1010
10	0x0A	LF (NL line feed, new line)	Newline key
11	0x0B	VT (vertical tab)	Vertical tab character
0000 1100	##014	12	##FF (NP form feed, new page)	Page key
015	13	0x0D	CR (carriage return)	Enter key
016	14	0x0E	SO (shift out)	No need to switch
017	15	0x0F	SI (shift in)	Enable switching
020	16	##0x10	DLE (data link escape)	Data link escape	##0001 0001
021	17	0x11	DC1 (device control 1)	Device Control 1	0001 0010
022	18	0x12			##0001 0011
19	0x13	DC3 (device control 3)	Device control 3		##024
20	0x14	DC4 (device control 4)	Device control 4	0001 0101	025
				0001 0110	026
	0x16	##SYN (synchronous idle)	synchronous idle
0001 0111	027
031	25	0x19	EM (end of medium)	MEDIA END
032	26	##0x1A	##SUB (substitute)	replace	0001 1011
033	27	0x1B	ESC (escape)	Escape (overflow)	0001 1100
034	28	0x1C	FS (file separator)	File separator	0001 1101
035	29				0001 1110
		##RS (record separator )	Record delimiter		0001 1111
31	0x1F	US (unit separator)	Unit separator
32	0x20	(space)	space			041	33	##0x21	!	Exclamation mark
0010 0010
045	37	##0x25	##%	Percent sign	##0010 0110
38	0x26	&	和		0010 0111
39	0x27	'	Closing single quote
40	0x28	(	##open bracket	0010 1001	051
41	0x29	)	Closing bracket	##0010 1010	052
		## Asterisk		0010 1011	053
0x2B		plus sign	##0010 1100	054	44	0x2C	##,	comma
0010 1101				##Minus sign/dash
056	46	0x2E	.	##Period	##0010 1111
057	47	0x2F	/	slash	##0011 0000
					0011 0001
					##0011 0010
50	##0x32	2	##Character 2	0011 0011	063
51	0x33	3	Character 3	0011 0100	064
52	0x34	4		0011 0101	065
0x35	5	Character 5
0x36	6	Characters 6
0x37	7	Characters 7
##0011 1000	070	56	0x38	8	Characters 8
073	59	##0x3B	;	##Semicolon	0011 1100
074	60	0x3C	<	Less than	0011 1101
075	61	0x3D	=	EQUAL SIGN	0011 1110
076					0011 1111
		##?	Question mark		0100 0000
64	0x40	@	Email symbol		0100 0001
65	0x41	A	Capital letter A		0100 0010
66	##0x42	B	Capital B
0100 0011	0103	67	0x43	##C	uppercase letter C
0100 0100	0104	68	0x44	D	Capital D
0100 0101	0105	69		##Capital E
0106	70	0x46	##F	uppercase Letters F	##0100 0111
			##Capital G		0100 1000
72	0x48	H	Capital letter H
73	0x49	I	Capital I	##01001010	0112
74	0x4A	J	Capital letter J	0100 1011	0113
75	0x4B	K	uppercase K	0100 1100	0114
76		##Capital L
##0x4D	M	Capital letter M
0100 1110	0116	78	0x4E	##N	uppercase letter N
0100 1111				##Capital letter O
0120	80	0x50	P	Capital P
0121	81	0x51	Q	Capital Q
0122	82	0x52	R	uppercase R
0123	##83	0x53	S	upper case S	0101 0100
0124	84				##0101 0101
85	0x55	U	Capital U
86	0x56	V	upper case V
87	0x57	W	upper case W
##88			Capital X
0101 1001	0131	89	0x59	Y	uppercase letter Y
0101 1010	0132	90	0x5A	Z	Capital letter Z
0101 1011	0133	91	##0x5B	[	Open square brackets
0135	93	0x5D	]	Closed square bracket
0136	94	0x5E	^	Caret
##0137	95	#0x5F	_	underscore	##0110 0000
					##0110 0001
97	0x61	a	lower case a		0110 0010
##98	0x62	b	##lower case b	0110 0011	0143
##0x63	c	lowercase letter c
0110 0100	0144	100	0x64	d	lower case d
0110 0101	##0145	101
##0146	102	0x66	f	Lower case f	##0110 0111
0147	103	0x67	g		0110 1000
			##Lowercase letter h
##105				0110 1010	0152
	##j	##lowercase j
0x6B	k	lower case k		##0154	108
			##0110 1101	0155	109
m	Lower case m		##0156	110	0x6E
n	lower case n
0110 1111	0157	111	0x6F	o	lowercase o
0111 0000	0160	##112
0161	113	0x71	q	Lower case q
0162	114	0x72	r	lower case r
0163	115	0x73	s	lower case s
##0164	116				##0111 0101
117	0x75	u	lowercase u		##0166
118	0x76	v	lower case v	0111 0111	0167
119	0x77	w	lowercase w	0111 1000	0170
120	0x78	x		0111 1001	0171
0111 1010	0172	122	0x7A	z	lowercase z
0111 1011	##0173	123
0174	124	0x7C	|	vertical line
##0175	125	0x7D	}	Closing curly brace	0111 1110
0176	126	0x7E	~	tilde	##0111 1111
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