ASCII / UNICODE Flashcards Preview

Paper 2 - Computer Science > ASCII / UNICODE > Flashcards

Flashcards in ASCII / UNICODE Deck (13)
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1

What is a character set?
Give examples

A collection of characters and the binary code used to represent them
ASCII, Unicode

2

How many bits does standard ASCII use to represent a character?

7 bits are used to represent a character

3

How many characters can be represented in standard ASCII?

2^7 = 128 different characters

4

What is the range of characters that can be represented in standard ASCII?

0 - 127

5

When is an 8th bit sometimes added to standard ASCII ?

It's sometimes used as a parity bit for error checking during transmission

6

How many bits does extended ASCII use to represent a character?

8 bits are used to represent a character

7

How many characters can be represented in extended ASCII?

2^8 = 256 different characters

8

What is the range of characters that can be represented in extended ASCII?

0-255

9

How many coding standards does Unicode support?
Name them.

Unicode supports 3 standards
UTF-8 , UTF-16, UTF-32

10

What advantage is gained from using Unicode as the character set over ASCII?

ASCII can only represent a fixed amount of characters due to how many bits it uses so it limits how many characters it can represent whereas Unicode uses more bits so can represent a greater amount of characters, such as characters used in different languages/alphabets

11

What is a character code?

A binary pattern equivalent of a character

12

What is a disadvantage of using Unicode?

It uses more bytes per character so uses more storage space per character

13

What's an advantage of using the stored program concept?

It allows one computer to run several different programs