Unit 2 : Data Representation Flashcards
What is the goal of a computer representing data?
- Represent enough of the real world data to satisfy our computational needs and our senses of sight and sound
List out 2 ways for representing information
- Analog
- Digital
What is analog data?
- Analog data is a continuous representation, analogous to the actual information it represents
What is digital data?
- It is a discrete representation, breaking the information up into separate ( discrete ) elements
Can computer work with analog data?
- It cannot work with analog information directly without the digitise process ( changing data to 0 and 1 )
How can we digitalise the analog information?
- It was done by breaking the analog information into pieces and representing those pieces using binary digits
Will electronic signals ( analog and digital ) degrade as they move down a line?
- Yes
What will happen when an analog signal digrades?
- Information is lost
- Because any voltage level within the range is valid, it is impossible to know that the original signal was even changed
What will happen when an digital signal degrades?
- We can still retrieve the infrormation form a readonably degraded digital signal
- No information is lost as long as it is reclocked and regain its original shape before too much degration
What is the difference between the representation of analog and digital data?
- Analog - Continuous Waveforms
- Digital - Binary Values
What is the difference between the nature of analog and digital data?
- Analog - Continuous
- Digital - Discrete
What is the difference between the signal type of analog and digital data?
- Analog - Change over time ( Vary smoothly over time )
- Digital - Have distinct levels
What is the difference between the accuracy of analog and digital data?
- Analog - More accurate representation of real-world data
- Digital - Less accurate but easier to process
What is the difference between the storage of analog and digital data?
- Analog - Typically stored on analog device ( vinyl )
- Digital - Stored digitally in binary format ( SSD )
What is the difference between the processing of analog and digital data?
- Analog - Required analog circuits for processing
- Digital - Processed by digital circuits and computers
What is the difference between the conversion of analog and digital data?
- Analog - Requires Analog-to-Digital ( ADC ) and Digital-to-Analog ( DAC ) converters for used in digital systems
- Digital - Does not require conversion if already digital
What is the difference between the transmission of analog and digital data?
- Analog - Degrades over long distances
- Digital - Can be transmitted over long distances with minimal degration
Was early computer binary? If no, it was what ?
- No, it was decimal
List out the early computer that uses decimal ( 2 )
- Mark I
- ENIAC
How many values does boolean logic consists?
- 2
- True / False
On / Off
Yes / No
1 / 0
Who proposed binary data processing?
- John von Neumaan
What are the benefits of binary data processing ( 2 )
- Simplified computer design
- Used for both instructions and data
What is decimal , binary , octal and hexadecimal also call as?
- Base 10 ( 0 - 9 )
- Base 2 ( 0 and 1 )
- Base 8 ( 0 -7 )
- Base 16 ( 0 - 9 , A - F )
What is 8 bits equal to?
- 1 byte
How many bytes does a word consists?
- 4 bytes
How to calculate from base 8 to base 10
- Find out how many place ( 624 has 3 places )
- Assign power to 8 according to the place ( 3 places so have 8^2 , 8^1 , 8^0 )
- Evaluate ( 6 x 8^2 , 2 x 8^1 , 1 x 8^0 )
How to calculate from base 16 to base 10
- Find out how many place ( 6704 has 4 places )
- Assign power to 16 according to the place ( 4 places so have 16^3 , 16^2 , 16^1 , 16^0 )
- Evaluate ( 6 x 16^3 , 7 x 16^2 , 0 x 16^1 , 4 x 16^0 )
How to calculate from base 2 to base 10
- Find out how many place ( 010 has 3 places )
- Assign power to 2 according to the place ( 3 places so have 2^2 , 2^1 , 2^0 )
- Evaluate ( 0 x 2^2 , 1 x 2^1 , 0 x 2^0 )
What is the formula for possible numbers?
- R = B^K
R - Range
B - Base
K - Number Of Digits
- Example:
1. Base 10, 2 digits
R = 10^2 ( 100 )
- Base 2, 16 digits
R = 2^16 ( 65536 or 64K )
- 16 bit PC can store 64K different number values
What will happen when the base was larger ( 2 )
- The more symbols required
- Fewer digits needed
How can we calculate from base 10 to base 2
- List out base 2 required digits ( 42 means until 5 digits 100000 - 32 )
- Divide the value ( 42 / 32 )
- IF has reminder , write 1, no reminder, write 0
- Continue the step until finish
How to calculate from base 10 to base 16
- List out base 16 required digits ( 5735 means until 4 digits 16^3 still 4096, 16^4 65536 )
- Divide the value ( 5735 / 4096 = 1 reminder )
- If has reminder, write 1 or the respected value, or write 0
- We need to minus the value from what we divided ( 5735 - 4096 = 1639 )
- Use the minus value to divide the value ( 1639 / 256 ( 16^2 ))
- Repeat
- Minus value also needs to multiply the reminder
if ( 1639 / 256 = 6 ), we need to minus like this 1639 - 1536 ( 6 x 256 )
