2.1 - Data Representation Flashcards
Revision
What is Bit short for?
Binary Digit
How many numbers can be represented by a Bit? What are they?
2 Numbers.
They can be a 0 or a 1.
What is the smallest unit of storage?
Bit
What is a collection of 8 bits known as?
Byte
Order these from smallest to largest.
TB, KB, GB, Byte, MB, Bit
Bit, Byte, KB, MB, GB, TB
How many bytes are in a KB?
1024 Bytes
How many GB are in a TB?
1024 GB
How many bits are in a byte?
8 Bits
How many MB are in a GB?
1024 MB
How many KB are in an MB?
1024 KB
How much storage space would be required to store a characters in a text file (e.g. T, +, 7)
1 Byte
How much storage would be required to store the word “Computer” in a text file?
8 Bytes (One for each character)
How much storage would be required to store a 64 x 64 pixel jpeg file?
12 KB
How much storage would be required to store a 10-megapixel photo?
11 MB
How much storage would be required to store a five minute MP3 audio file?
5 MB
How much storage would be required to store one hour of video data?
2 GB
Is KB and Kb the same unit of measurement?
No.
KB stands for Kilobytes
Kb stands for Kilobits
To calculate the range of values for n bits we have to use which formula?
0 - (2n - 1)
If you were to write an 8 bit binary number. What is the left most bit known as?
Most Significant Bit (MSB)
If you were to write an 8 bit binary number. What is the right most bit known as?
Least Significant Bit (LSB)
If you are converting a denary number into its binary form, what are the headings you would use?
128 64 32 16 8 4 2 1
After you have worked out a binary value for a denary number what should you always do to ensure your answer is correct?
Add up all of the headings with a 1 underneath them to ensure that you have got the correct answer.
Why do we need to use a Two’s Complement System?
To allow for negative numbers to be shown
In Two’s Complement, the MSB becomes a _____________, to tell us if the number is either positive or negative.
If the number is positive you will see a _____ at the beginning of the binary number.
If the number is negative you will see a _____ at the beginning of the binary number.
- Sign Bit
- 0
- 1
What is the range of values for typical binary numbers?
0 - 255
What is the formula we use if we are finding Two’s Complement numbers?
(-2n - 1) to (2n-1 - 1)
When working out Two’s Complement numbers we have to go through 3 steps.
What is missing from each step?
Step 1: Convert 71 into ___________
Step 2: _________ the bits. Change 0’s to 1’s and 1’s to 0’s.
Step 3: Add ____
- Binary
- Flip
- 1
What is a character set?
- Set of symbols that may be represented in a computer at a particular time
- Symbols called characters can be classified as letters, numbers and punctuation marks.
- Each character has a unique binary code.
- These include displayable characters, letters, numbers and punctuation marks.
- Also contains “control” characters: Non-printing and used for special purposes e.g. end of file marker.
- Two examples include ASCII and Unicode
