ASCII format for network interchange
RFC 20
| Document | Type |
RFC - Internet Standard
(October 1969; Errata)
Status changed by status-change-rfc20-ascii-format-to-standard
|
|
|---|---|---|---|
| Last updated | 2015-01-28 | ||
| Stream | Legacy | ||
| Formats | plain text pdf html bibtex | ||
| Stream | Legacy state | (None) | |
| Consensus Boilerplate | Unknown | ||
| RFC Editor Note | (None) | ||
| IESG | IESG state | RFC 20 (Internet Standard) | |
| Telechat date | |||
| Responsible AD | (None) | ||
| Send notices to | (None) | ||
Network Working Group Vint Cerf
Request for Comments: 20 UCLA
October 16, 1969
ASCII format for Network Interchange
For concreteness, we suggest the use of standard 7-bit ASCII embedded
in an 8 bit byte whose high order bit is always 0. This leads to the
standard code given on the attached page, copies from USAS X3, 4-
1968. This code will be used over HOST-HOST primary connections.
Break characters will be defined by the receiving remote host, e.g.
SRI uses "." (ASCII X'2E' or 2/14) as the end-of-line character,
where as UCLA uses X'OD' or 0/13 (carriage return).
USA Standard Code for Information Interchange
1. Scope
This coded character set is to be used for the general interchange of
information among information processing systems, communication
systems, and associated equipment.
Cert [Page 1]
RFC 20 ASCII format for Network Interchange October 1969
2. Standard Code
|----------------------------------------------------------------------|
B \ b7 ------------>| 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 |
I \ b6 ---------->| 0 | 0 | 1 | 1 | 0 | 0 | 1 | 1 |
T \ b5 -------->| 0 | 1 | 0 | 1 | 0 | 1 | 0 | 1 |
S |-----------------------------------------------|
COLUMN->| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|b4 |b3 |b2 |b1 | ROW | | | | | | | | |
+----------------------+-----------------------------------------------+
| 0 | 0 | 0 | 0 | 0 | NUL | DLE | SP | 0 | @ | P | ` | p |
|---|---|---|---|------|-----|-----|-----|-----|-----|-----|-----|-----|
| 0 | 0 | 0 | 1 | 1 | SOH | DC1 | ! | 1 | A | Q | a | q |
|---|---|---|---|------|-----|-----|-----|-----|-----|-----|-----|-----|
| 0 | 0 | 1 | 0 | 2 | STX | DC2 | " | 2 | B | R | b | r |
|---|---|---|---|------|-----|-----|-----|-----|-----|-----|-----|-----|
| 0 | 0 | 1 | 1 | 3 | ETX | DC3 | # | 3 | C | S | c | s |
|---|---|---|---|------|-----|-----|-----|-----|-----|-----|-----|-----|
| 0 | 1 | 0 | 0 | 4 | EOT | DC4 | $ | 4 | D | T | d | t |
|---|---|---|---|------|-----|-----|-----|-----|-----|-----|-----|-----|
| 0 | 1 | 0 | 1 | 5 | ENQ | NAK | % | 5 | E | U | e | u |
|---|---|---|---|------|-----|-----|-----|-----|-----|-----|-----|-----|
| 0 | 1 | 1 | 0 | 6 | ACK | SYN | & | 6 | F | V | f | v |
|---|---|---|---|------|-----|-----|-----|-----|-----|-----|-----|-----|
| 0 | 1 | 1 | 1 | 7 | BEL | ETB | ' | 7 | G | W | g | w |
|---|---|---|---|------|-----|-----|-----|-----|-----|-----|-----|-----|
| 1 | 0 | 0 | 0 | 8 | BS | CAN | ( | 8 | H | X | h | x |
|---|---|---|---|------|-----|-----|-----|-----|-----|-----|-----|-----|
| 1 | 0 | 0 | 1 | 9 | HT | EM | ) | 9 | I | Y | i | y |
|---|---|---|---|------|-----|-----|-----|-----|-----|-----|-----|-----|
| 1 | 0 | 1 | 0 | 10 | LF | SUB | * | : | J | Z | j | z |
|---|---|---|---|------|-----|-----|-----|-----|-----|-----|-----|-----|
| 1 | 0 | 1 | 1 | 11 | VT | ESC | + | ; | K | [ | k | { |
|---|---|---|---|------|-----|-----|-----|-----|-----|-----|-----|-----|
| 1 | 1 | 0 | 0 | 12 | FF | FS | , | < | L | \ | l | | |
|---|---|---|---|------|-----|-----|-----|-----|-----|-----|-----|-----|
| 1 | 1 | 0 | 1 | 13 | CR | GS | - | = | M | ] | m | } |
|---|---|---|---|------|-----|-----|-----|-----|-----|-----|-----|-----|
| 1 | 1 | 1 | 0 | 14 | SO | RS | . | > | N | ^ | n | ~ |
|---|---|---|---|------|-----|-----|-----|-----|-----|-----|-----|-----|
| 1 | 1 | 1 | 1 | 15 | SI | US | / | ? | O | _ | o | DEL |
+----------------------+-----------------------------------------------+
Cert [Page 2]
RFC 20 ASCII format for Network Interchange October 1969
3. Character Representation and Code Identification
The standard 7-bit character representation, with b7 the high-order
bit and b1 the low-order bit, is shown below:
EXAMPLE: The bit representation for the character "K," positioned in
column 4, row 11, is
b7 b6 b5 b4 b3 b2 b1
1 0 0 1 0 1 1
The code table position for the character "K" may also be represented
by the notation "column 4, row 11" or alternatively as "4/11." The
decimal equivalent of the binary number formed by bits b7, b6, and
Show full document text