ASCII
𐑨𐑕𐑒𐑦
ASCII (the American Standard Code for Information Interchange) is a popular character set, introduced in 1963, and extended by UTF-8 starting in 1991. (It was previously extended by various code pages that we'd best not dwell on.)
It was used by both Unix and CP/M, and by extension, most other operating systems too. A notable exception is the 8-bit home computers.
It rather sensibly features every digit and letter in alphabetical order, so that sorting a list of strings by their first character numerically, and within that their second character numerically, and so on, is inherently the same thing as alphabetising them. Contrast with, say, Baudot.
Also rather sensibly, the uppercase and lowercase versions of a given letter differ only by a single bit, making it relatively easy to translate between them using bitwise logic.
The ASCII characters you're likely to actually encounter are:
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | A | B | C | D | E | F | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | NUL | BEL | BS | HT | LF | CR | ||||||||||
| 1 | ESC | |||||||||||||||
| 2 | SP | ! | " | # | $ | % | & | ' | ( | ) | * | + | , | - | . | / |
| 3 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | : | ; | < | = | > | ? |
| 4 | @ | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O |
| 5 | P | Q | R | S | T | U | V | W | X | Y | Z | [ | \ | ] | ^ | _ |
| 6 | ` | a | b | c | d | e | f | g | h | i | j | k | l | m | n | o |
| 7 | p | q | r | s | t | u | v | w | x | y | z | { | | | } | ~ |
On a Unix system, the appropriate manual page can be shown using man ascii.
Downloads
Documentation
- "ASCII format for Network Interchange" Vint Cerf, Oct 1969
Character sets: ASCII | Useful Unicode characters
