ASCII stands for “American Standard Code for Information Interchange” which was developed by the American National Standards Institute. It is a code used by computers to represent characters in numbers. In the ASCII code, 128 English characters have a unique number between 0 and 127 to represent them. Each character in upper case and lower has different numbers, for example, the ASCII code capital M is 77 and for small m is 109. The operating system like Unix and DOS uses the ASCII code and Windows NT and 2000 uses Unicode which is newer in comparison to ASCII code.
Standard and Extended ASCII
Standard ASCII represents 128 English characters and uses 7 bits to represent every character. Standard ASCII also has ASCII code for computer keyboard keys like Escape key is represented by 27 in ASCII. Extended ASCII represents special characters and characters from other languages. The special character like “é” represented by 233 in Extended ASCII code.
How ASCII code works
When you press a key of your keyboard or you send and receive a text is a set of numbers. Each set of numbers represents characters that you have received or sent. Since the standard ASCII range is 0 to 127, only 7 bits or 1 byte of data is needed. For example, to send the string “Hello” as ASCII it would translate to 72 101 108 108 111.
Standard or lower ASCII characters and codes
ASCII is divided into three different sections Non-printable, Lower ASCII and Higher ASCII.
The system code codes between 0 and 31 are Non-printable.
The codes between 32 and 127 are Lower ASCII. These codes workes on 7-bit character tables.
The codes between 128 and 255 are Higher ASCII. These characters mostly used in a programming language.