# ASCII Table

Dec | Hex | Char | Description | Dec | Hex | Char | Dec | Hex | Char | Dec | Hex | Char
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
0 | 0 | NUL | (null) | 32 | 20 |  | 64 | 40 | @ | 96 | 60 | `
1 | 1 | SOH | (start of heading) | 33 | 21 | ! | 65 | 41 | A | 97 | 61 | a
2 | 2 | STX | (start of text) | 34 | 22 | " | 66 | 42 | B | 98 | 62 | b
3 | 3 | ETX | (end of text) | 35 | 23 | # | 67 | 43 | C | 99 | 63 | c
4 | 4 | EOT | (end of transmission) | 36 | 24 | $ | 68 | 44 | D | 100 | 64 | d
5 | 5 | ENQ | (enquiry) | 37 | 25 | % | 69 | 45 | E | 101 | 65 | e
6 | 6 | ACK | (acknowledge) | 38 | 26 | & | 70 | 46 | F | 102 | 66 | f
7 | 7 | BEL | (bell) | 39 | 27 | ' | 71 | 47 | G | 103 | 67 | g
8 | 8 | BS | (backspace) | 40 | 28 | ( | 72 | 48 | H | 104 | 68 | h
9 | 9 | TAB | (horizontal tab) | 41 | 29 | ) | 73 | 49 | I | 105 | 69 | i
10 | A | LF | (NL line feed, new line) | 42 | 2A | * | 74 | 4A | J | 106 | 6A | j
11 | B | VT | (vertical tab) | 43 | 2B | + | 75 | 4B | K | 107 | 6B | k
12 | C | FF | (NP form feed, new page) | 44 | 2C | , | 76 | 4C | L | 108 | 6C | l
13 | D | CR | (carriage return) | 45 | 2D | - | 77 | 4D | M | 109 | 6D | m
14 | E | SO | (shift out) | 46 | 2E | . | 78 | 4E | N | 110 | 6E | n
15 | F | SI | (shift in) | 47 | 2F | / | 79 | 4F | O | 111 | 6F | o
16 | 10 | DLE | (data link escape) | 48 | 30 | 0 | 80 | 50 | P | 112 | 70 | p
17 | 11 | DC1 | (device control 1) | 49 | 31 | 1 | 81 | 51 | Q | 113 | 71 | q
18 | 12 | DC2 | (device control 2) | 50 | 32 | 2 | 82 | 52 | R | 114 | 72 | r
19 | 13 | DC3 | (device control 3) | 51 | 33 | 3 | 83 | 53 | S | 115 | 73 | s
20 | 14 | DC4 | (device control 4) | 52 | 34 | 4 | 84 | 54 | T | 116 | 74 | t
21 | 15 | NAK | (negative acknowledge) | 53 | 35 | 5 | 85 | 55 | U | 117 | 75 | u
22 | 16 | SYN | (synchronous idle) | 54 | 36 | 6 | 86 | 56 | V | 118 | 76 | v
23 | 17 | ETB | (end of trans. block) | 55 | 37 | 7 | 87 | 57 | W | 119 | 77 | w
24 | 18 | CAN | (cancel) | 56 | 38 | 8 | 88 | 58 | X | 120 | 78 | x
25 | 19 | EM | (end of medium) | 57 | 39 | 9 | 89 | 59 | Y | 121 | 79 | y
26 | 1A | SUB | (substitute) | 58 | 3A | : | 90 | 5A | Z | 122 | 7A | z
27 | 1B | ESC | (escape) | 59 | 3B | ; | 91 | 5B | [ | 123 | 7B | {
28 | 1C | FS | (file separator) | 60 | 3C | < | 92 | 5C | \ | 124 | 7C | |
29 | 1D | GS | (group separator) | 61 | 3D | = | 93 | 5D | ] | 125 | 7D | }
30 | 1E | RS | (record separator) | 62 | 3E | > | 94 | 5E | ^ | 126 | 7E | ~
31 | 1F | US | (unit separator) | 63 | 3F | ? | 95 | 5F | _ | 127 | 7F | DEL

## Format control

### BS

Backspace. Indicates movement of the printing mechanism or display cursor backwards in one position.

### HT

Horizontal Tabulation. Indicates movement of the printing mechanism or display cursor forward to the next preassigned 'tab' or stopping position.

### LF

Line Feed. Indicates movement of the printing mechanism or display cursor to the start of the next line (ie one line down).

### VT

Vertical Tabulation. Indicates movement of the printing mechanism or display cursor to the next of a series of preassigned printing lines.

### FF

Form Feed. Indicates movement of the printing mechanism or display cursor to the starting position of the next page, form, or screen.

### CR

Carriage Return. Indicates movement of the printing mechanism or display cursor to the starting position (left) of the current line.

## Transmission control

### SOH

Start of Heading. Used to indicate the start of a heading which may contain address or routing information.

### STX

Start of Text. used to indicate the start of the text and so also indicates the end of the heading.

### ETX

End of Text. Used to terminate the text which was started with STX. End of Transmission indicates the end of a transmission which may have included one or more 'texts' with their headings.

### ENQ

Enquiry. A request for a response from a remote station. It may be used as a "who are you?" request for a station to identify itself.

### ACK

Acknowledge. A character transmitted by a receiving device as an affirmation response to a sender. It is used as a positive response to polling messages.

### NAK

Negative Acknowledgement. A character transmitted by a receiving device as a negative response to a sender. It is used as a negative response to polling messages.

### SYN

Synchronous/Idle. Used by a synchronous transmission system to achieve synchronisation. When no data is being sent a synchronous transmission system may send SYN characters continuously.

### ETB

End of Transmission Block. Indicates the end of a block of data for communication purposes. It is used for blocking data where the block structure is not necessarily related to the processing format.

## Information separator

### FS

File Separator.

### GS

Group Separator.

### RS

Record Separtator.

### US

Unit Separator.

Information separators to be used in an optional manner except that their heirarchy shall be FS (the most inclusive) to US (the least inclusive).

## Miscellaneous

### NUL

Null. No character. Used for filling in time or filling space on tape when there is no data.

### BEL

Bell. Used when there is need to call human attention. It may control alarm or attention devices.

### SO

Shift Out. Indicates that the code combinations which follow shall be interpreted as _outside_ the standard character set until an SI character is reached.

### SI

Shift In. Indicates that the code combinations which follow shall be interpreted according to the standard character set.

### DLE

Data Link Escape. A character which shall change the meaning of one or more contiguously following characters. It can provide supplementary controls or permits the sending of data characters having any bit combination.

### DC1, DC2, DC3, DC4

Device Controls. Characters for the control of ancillary devices or special terminal features.

### CAN

Cancel. Indicates that the data which preceeds it in a message or block should be disregarded (usually because an error has been detected).

### EM

End of Medium. Indicates the physical end of a card, tape or other medium, or the end of the required or used portion of the medium.

### SUB

Substitute. Substituted for a character that is found to be erroneous or invalid.

### ESC

Escape. A character intended to provide code extension in that it gives a specified number of contiguously following characters an alternate meaning.

### SP

Space. A nonprinting character used to separate words, or to move the printing mechanism or display cursor forward by one position.

### DEL

Delete. Used to obliterate unwanted characters (for example, on paper tape by punching a hole in _every_ bit position).

Contributor: | Joakim Ögren

Source: | ASCII table at The Pin-Out directory
| Data & Computer Communications from Stallings

Copyright © The Hardware Book Team 1996-2004.
May be copied and redistributed, partially or in whole, as appropriate.
Document last modified: 2002-01-13