1.1-1.2 System architecture, memory and storage

Question 1

What is software?

Answer 1

Name for the programs which provide instructions for the computer

Question 2

Explain the fetch, decode, execute cycle?

Answer 2

Fetch data/ instructions from memory
Decode it
Execute it

Question 3

What is the CPU made up of?

Answer 3

Billions of transistors

Question 4

What are some common components found in the CPU?

Answer 4

ALU
CU
Cache
Registers

Question 5

Explain the control unit?

Answer 5

coordinates CPUs activity

Question 6

Explain the ALU

Answer 6

Arithmetic operations like +-/*, logic like AND, OR,

Carries out calculations and logical decisions

Question 7

Explain Cache?

Answer 7

Provide temporary storage that the CPU can access very quickly

Question 8

Explain what Registers are?

Answer 8

Memory locations within CPU that hold data temporarily, accessed quickly

Question 9

Explain what Registers do?

Answer 9

Accept, store and transfer data and instructions for CPU

Question 10

Name 4 registers

Answer 10

PC
MDR
MAR
ACC

Question 11

What is the program counter?

Answer 11

Keeps track of memory location for the next instruction

Question 12

What is the MDR?

Answer 12

Store any data fetched from memory or any data that is to be transferred

Question 13

What is the MAR?

Answer 13

Stores the location in memory to be used by the MDR , where it is sending or fetched from

Question 14

What is the Accumulator?

Answer 14

Holds the result of any calculations made by the ALU

Question 15

What affects the CPUs performance?

Answer 15

Clock speed - constant fetch, execute cycle.
Cache size - accessing cache is a lot quicker than normal memory

Question 16

How fast is cache?

Answer 16

4GHz / 4 billion

Question 17

What is an embedded system?

Answer 17

Specific function as a part of a larger device

Question 18

Characteristics of an embedded system?

Answer 18

Low power
small in size
Low cost
Dedicated software

Question 19

Examples of an embedded system?

Answer 19

Washing machine, dishwasher, microwave

Question 20

What is the difference between RAM and ROM?

Answer 20

RAM - needs power to maintain contents, read and write.
ROM - doesnt require power to maintain content, computer cannot over write its content, holds data and instructions needed to start up the computer

Question 21

Is RAM volatile?

Answer 21

Yes, temporary

Question 22

What is the difference between primary and secondary storage?

Answer 22

Primary is faster and mostly volatile
Secondary is non volatile and much slower

Question 23

Give an example of magnetic storage (Secondary)

Answer 23

HDD - hard disk drive

Question 24

Positives and negatives of magnetic storage?

Answer 24

Cheap, large capacity, portable, slow access time, fragile

Question 25

What is flash memory?

Answer 25

Storing data based on electronics

Question 26

What is latency?

Answer 26

Delay before data is transferred

Question 27

Positives and negatives of Solid state storage?

Answer 27

Very fast access time, portable Low capacity, expensive

Question 28

Give an example of optical storage?

Answer 28

DVD-R , CD

Question 29

How are optical storage written to and read from?

Answer 29

Using laser light, pits and lands

Question 30

Positives and Negatives of optical storage

Answer 30

Portable , cheap Easily damaged ,

Question 31

Give an example of SSD

Answer 31

Memory stick

Question 32

With 2 bits, how many colours can you score?

Answer 32

2^2 = 4 its 2^(how many bits)

Question 33

What is metadata?

Answer 33

Data about the data

Question 34

What does metadata include?

Answer 34

Number of bits per pixel The size of the image in bits

Question 34

What is colour depth?

Answer 34

Number of bits used per pixel, more bits per pixel, the larger the range of colours we have in the image

Question 34

What is the resolution?

Answer 34

The number of pixels per unit of distance

Question 35

How do you work out file size? You have the height and width

Answer 35

Height x width

Question 36

What is the sample rate with sound?

Answer 36

Number of samples taken per second

Question 37

What is sound measured in?

Answer 37

Hertz

Question 38

What does the size of the sound file depend on?

Answer 38

Sample rate Duration Bit depth Number of channels

Question 39

How do you work out size of file? You have duration, sample rate, bit depth, and channels

Answer 39

Bit depth x number of channels x sample rate x duration

Question 40

What are the two types of compression?

Answer 40

Lossy Lossless

Question 41

What is lossy compression?

Answer 41

Data is permanently removed to make the file smaller

Question 42

Is lossy good for photos or text?

Answer 42

Photos

Question 43

How does lossless compression work?

Answer 43

Recreating the original file exactly, but using an index to make it smaller

Question 44

Is lossless reversable?

Answer 44

Yes

Question 45

Is lossy noticable?

Answer 45

Not likely to be noticed to the human eye or ear, but there is some loss of detail