Data Representation Question: Characters If you type your name into the keyboard, how does the computer know how to show the correct characters? Data Representation Characters

Data Representation Objectives BEGINNER: Explain the use of binary codes to represent characters. ADVANCED: Know the term character set. EXPERT: Describe with examples the relationship between the number of bits. Starter activity Using these decimal codes, what would the word Computing look like?

ASCII Objectives BEGINNER: Explain the use of binary codes to represent characters. ADVANCED: Know the term character set. EXPERT: Describe with examples the relationship between the number of bits. This code is called ASCII(American Standard Code for Information Interchange) and is used to allow the computer to understand the characters that have been typed in by a human. The word ‘Computing’ uses the denary codes: 67 111 109 112 117 116 105 110 103 Obviously the computer would recognise these in Binary as: 01000011 01101111 01101101 01110000 01110101 01110100 01101001 01101110 01100111 Each character is given a unique binary code and that is how the computer can represent the correct character. You will notice that each character is stored in 8 bits but only uses 7 bits. The 8th bit can be used as an addition e.g. languages where they need more characters. This is known as ‘Extended ASCII’. Starter activity ASCII uses 1 byte to store all of the characters needed for the English language. This gives 256 possible characters which is enough for the English language. However what would other languages use such as Arabic where they have thousands of characters?

Data Representation UNICODE Objectives CHARACTER SET BEGINNER: Explain the use of binary codes to represent characters. ADVANCED: Know the term character set. EXPERT: Describe with examples the relationship between the number of bits. UNICODE Unicode was developed to account for every language in the world. It uses 2 bytes that give us 216 possibilities (65,536). An example use of this would allow a user from any country to select their language when setting up an operating system. The Unicode character set would account for every language. Starter activity CHARACTER SET ASCII and Unicode are the most widely used character sets. The term Character set is used to describe the possible characters that can be represented in a computer system.