ASCII

ASCII

How computers represent text

Multiple Select

In this lesson you are going to ...

• Define 'character set'

• Describe 7-bit ASCII

• Work out ASCII code for a given character

• understand limitations of ASCII

Multiple Select

Choose all the types of information that are encoded as binary by computers ...

• Text

• Images

• Videos

• Animations

Multiple Select

What binary representations have your learned about so far in GCSE Computer Science?

• Signed integers

• Unsigned integers

• Floating-point numbers

• Bitmap images

Fill in the Blanks

ASCII is the American Standard Code for Information

Multiple Choice

Choose the best word to completre this sentence.

"ASCII was created to allow computing devices to communicate with each other and for the received message to be _______ to the sent message"

• identical

• similar

• different

• opposite

Multiple Choice

How many bits did the original ASCII system use for each character?

• 7

• 8

• 16

• 256

Fill in the Blanks

How many characters were represented by the original ASCII system?

Multiple Choice

A list of the input symbols that a computer is able to translate?

• character set

• instruction set

• alphabet

• programming language

Fill in the Blanks

How many bits are required to encode all the letters of the alphabet 'a'-'z'?

Fill in the Blanks

What is the difference between the code for 'a' and the code for 'A'?

Multiple Choice

Why do you think that 65 and 97 were chosen as the ASCII values for 'A' and 'a'?

• The least significant 5 bits represent 1

• It was just a random choice

• You need 6 bits to represent both numbers

• There is a difference of 32 between them

Fill in the Blanks

If the 7-bit binary ASCII value for 'A? is 1000001, what is the binary value for 'F'?

Fill in the Blanks

If the character 'a' has the 7-bit binary ASCII value 110 001, what character has the binary value 110 1011?

Multiple Choice

The original ASCII system used 7 bits to represent 128 characters. Extended ASCII was introduced later and used 8 bits to represent how many characters?

• 128

• 256

• 512

• 1024

Fill in the Blanks

What was created in order to represent the characters from other alphabets such as Arabic and Cyrillic?

Multiple Choice

As of 2021, approximately how many symbols are represented in Unicode?

• 48,000

• 148,000,000

• 148,000

• 1,480,000

Open Ended

Thinking Hard:

Write down 3 questions that this lesson has answered...

(press shift+Enter for a new line)

Multiple Select

In this lesson I have learned to ......

• Define "character set"

• describe 7-bit ASCII characters

• derive the ASCII code for a character

• understand limitations of ASCII system

Poll

How much of this lesson have you understood?

• None of it

• Some of it

• Most of it

• All of it