Data representation

What does 1 and 0s represent?

Represent the flow of electricity

1s = used to show that electricity is flowing

0s = used to show that electricity isnt flowing

Each 1s and 0s is a bit

What are the measures of data?

Bit (b) = a single binary bit (1 per 1s and 0s)

Nibble = 4 bits

Byte (B) = 8 bits

Kilobyte (kB) = 1000 kilobytes

Gigabyte (GB) = 1000 megabytes

Terabyte (TB) = 1000 gigabytes

Petabyte (PB) = 1000 terabytes

What is the system denary? Whats it also known as?

Our normal number system (0-9)

It also known as base-10

What is the binary system?

A numerical system that uses only two digits, 0 and 1

How do we use binary to make a denary number eg 11?

A binary table:

Make the number 11

8s / 4s / 2s / 1s

1 / 0 / 1 / 1 = 1011

1×8=8

0×4=0

2×1=2

1×1=1

8+0+2+1 = 11

How do we convert between binary to denary?

Write a binary number line and convert the number 89 to binary

128 / 64 / 32 / 16 / 8 / 4 / 2 / 1

0 / 1 / 0 / 1 / 1 / 0 / 0 / 1

64+16+8+1= 89 = 01011001

How to you conveter from binary to denary?

Write in the binary numberline and fill in the binary numer

128 / 64 / 32 / 16 / 8 / 4 / 2 / 1

0 / 1 / 0 / 1 / 1 / 0 / 0 / 1

/ 64 / / 16 / 8 / / / 1 = 89

How do we use column addition on binary?

1 + 1 = 1

0 + 0 = 0

1 + 0 = 10 (carry the one)

What is a overflow in binary?

When there are too many numbers (more then 8 bits)

The compuer stores the extra bit elsewhere

What happens to the data if there is a overflow?

There is a lost of accuracy and data

What are binary shifts?

Moves every number in the binary left or right

What happens when a binary number shifts to the left?

The number doubles/multipys moving to the left

We fill the new gaps in with 0s

This may lead to a overflow

What happens when a binary number shifts to the right?

The number divides/halves

We fill the new gaps in with 0s

What is the purpose if hexidecimal?

To simplify/make binary numbers smaller

How convert binary → hexidecimal

• Split the binary number in half and convert to a denary number

• If the number is over the number 9 it becomes a letter

16-base = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F

What are alphanumeric characters?

• Used to make words and strings

• This includes uppercase and lowercase letters, symbols and numbers 0-9

What are character sets?

Collections of characters that a computer recognises from their binary representation

What are alphanumeric characters?

Used to make words and strings

Include:

• Upper case and lower case

• 0-9

• Symbols

What are character sets?

Collections of characters that a computer recognises from their binary representation

Also contains special characters which do certain commands