The document discusses ASCII and Unicode, highlighting ASCII as a common format for text files that represents a limited set of English characters. Unicode is introduced as a multilingual character coding system that supports a broader range of characters from various languages and facilitates global communication. It details the different UTF formats, indicating their bit sizes and character set expansions.

1. Computer Science
(A Level)
ASCII and Unicode

2. A binary representation of a
particular letter, number or special
character
(Definitions)

3. • ASCII stands for “American Standard Code for Information
Interchange”
• It is the most common format for text files in computers on the
internet
• IT MAPS BINARY TO LETTERS/NUMBERS
• It represents text which makes it possible to transfer data from
one computer to another
• ASCII was used to facilitate communication between computers
by using the common language code
ASCII

4. ASCII
Limitations of ASCII
• Can only represent 127 or 255 characters
• Can only code for the standard English language
characters (not for others like Chinese/Arabic)

5. ASCII Table

6. • Unicode is an international and multilingual text character and coding
system
• Unicode uses more bits and therefore can be used for more character
combinations
• It was introduced so that lots of different characters from different
languages could be easily represented and entered
• It facilitates communication between devices all around the world
without relying on translation
Unicode

7. • Joe Becker published a draft of Unicode in August 1988.
Companies such as Apple and Xerox were involved in its creation
Unicode
UTF – 8 = Extended ASCII
= 8 Bits
UTF – 16 = Expands to western languages
= 16 Bits
UTF – 32 = Most complete character set
= 32 Bits
UNICODE: