ASCII - The American Standard Code for Information Interchange
The American National Standards Institute has published an American Standards Code for Information Interchange(ASCII)
This code is now most widely used by major manufactures. so that their equipment will be compatible with those of other manufactures.
ASCII is a computer code which uses 128 different coding combinations of a group of seven bits (27= 128) to represent
- Characters A to Z, both upper and lower case
- Special characters, < , ., ?, : ,etc.,
- Numbers 0 to 9
- Special control codes used in device control
Example Code the text string 'Hello.' in ASCII using hexadecimal digits.
H = 48
e = 65
l = 6C
l = 6C
o = 6F
. = 2E
H = 48
e = 65
l = 6C
l = 6C
o = 6F
. = 2E
Thus the string is represented by the byte sequence
48 65 6C 6C 6F 2E
48 65 6C 6C 6F 2E
ASCII Code Chart
HEX | DEC | CHR | CTRL | HEX | DEC | CHR | HEX | DEC | CHR | HEX | DEC | CHR | |||
00 | 0 | NUL | ^@ | 20 | 32 | SP | 40 | 64 | @ | 60 | 96 | ` | |||
01 | 1 | SOH | ^A | 21 | 33 | ! | 41 | 65 | A | 61 | 97 | a | |||
02 | 2 | STX | ^B | 22 | 34 | " | 42 | 66 | B | 62 | 98 | b | |||
03 | 3 | ETX | ^C | 23 | 35 | # | 43 | 67 | C | 63 | 99 | c | |||
04 | 4 | EOT | ^D | 24 | 36 | $ | 44 | 68 | D | 64 | 100 | d | |||
05 | 5 | ENQ | ^E | 25 | 37 | % | 45 | 69 | E | 65 | 101 | e | |||
06 | 6 | ACK | ^F | 26 | 38 | & | 46 | 70 | F | 66 | 102 | f | |||
07 | 7 | BEL | ^G | 27 | 39 | ' | 47 | 71 | G | 67 | 103 | g | |||
08 | 8 | BS | ^H | 28 | 40 | ( | 48 | 72 | H | 68 | 104 | h | |||
09 | 9 | HT | ^I | 29 | 41 | ) | 49 | 73 | I | 69 | 105 | i | |||
0A | 10 | LF | ^J | 2A | 42 | * | 4A | 74 | J | 6A | 106 | j | |||
0B | 11 | VT | ^K | 2B | 43 | + | 4B | 75 | K | 6B | 107 | k | |||
0C | 12 | FF | ^L | 2C | 44 | , | 4C | 76 | L | 6C | 108 | l | |||
0D | 13 | CR | ^M | 2D | 45 | - | 4D | 77 | M | 6D | 109 | m | |||
0E | 14 | SO | ^N | 2E | 46 | . | 4E | 78 | N | 6E | 110 | n | |||
0F | 15 | SI | ^O | 2F | 47 | / | 4F | 79 | O | 6F | 111 | o | |||
10 | 16 | DLE | ^P | 30 | 48 | 0 | 50 | 80 | P | 70 | 112 | p | |||
11 | 17 | DC1 | ^Q | 31 | 49 | 1 | 51 | 81 | Q | 71 | 113 | q | |||
12 | 18 | DC2 | ^R | 32 | 50 | 2 | 52 | 82 | R | 72 | 114 | r | |||
13 | 19 | DC3 | ^S | 33 | 51 | 3 | 53 | 83 | S | 73 | 115 | s | |||
14 | 20 | DC4 | ^T | 34 | 52 | 4 | 54 | 84 | T | 74 | 116 | t | |||
15 | 21 | NAK | ^U | 35 | 53 | 5 | 55 | 85 | U | 75 | 117 | u | |||
16 | 22 | SYN | ^V | 36 | 54 | 6 | 56 | 86 | V | 76 | 118 | v | |||
17 | 23 | ETB | ^W | 37 | 55 | 7 | 57 | 87 | W | 77 | 119 | w | |||
18 | 24 | CAN | ^X | 38 | 56 | 8 | 58 | 88 | X | 78 | 120 | x | |||
19 | 25 | EM | ^Y | 39 | 57 | 9 | 59 | 89 | Y | 79 | 121 | y | |||
1A | 26 | SUB | ^Z | 3A | 58 | : | 5A | 90 | Z | 7A | 122 | z | |||
1B | 27 | ESC | 3B | 59 | ; | 5B | 91 | [ | 7B | 123 | { | ||||
1C | 28 | FS | 3C | 60 | < | 5C | 92 | \ | 7C | 124 | | | ||||
1D | 29 | GS | 3D | 61 | = | 5D | 93 | ] | 7D | 125 | } | ||||
1E | 30 | RS | 3E | 62 | > | 5E | 94 | ^ | 7E | 126 | ~ | ||||
1F | 31 | US | 3F | 63 | ? | 5F | 95 | _ | 7F | 127 | DEL |