1.3 Storage COMPLETE Flashcards Preview

GCSE Computer Science (OCR) > 1.3 Storage COMPLETE > Flashcards

Flashcards in 1.3 Storage COMPLETE Deck (79)
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1
Q

What is secondary storage?

A

Storage location which permanently stores OS, programs and data.

2
Q

What is the purpose of secondary storage?

A

To use the data later.
To use the software.
To interact with the computer.

3
Q

How do optical drives work?

A

A laser light marks patterns into the disk which represent 0’s and 1’s.
Then the laser light detects where the marks are and translates them into a readable format.

4
Q

How do magnetic drives work?

A

They read / write across the medium and change how magnetised that part of the medium is.
Each level of magnetism represents 0’s and 1’s.

5
Q

What are the properties (made up of and characteristics) of solid state/flash drives?

A

They are made up of silicon microchips (switches).
They are fast but the most expensive and have no moving parts.
On = 1.
Off = 0.

6
Q

How much data does one character represent?

A

1 byte per character.

7
Q

What percentage overheads do you need when calculating data?

A

10%.

But only use if the question specifies.

8
Q

True/False: Data can be stored on secondary storage devices

A

True

9
Q

What are the three main types of storage device?

A

Magnetic discs, optical discs and solid-state (flash) memory

10
Q

Data and programs are stored temporarily/permanently on secondary storage devices

A

permanently

11
Q

Why must data stored on secondary storage devices be loaded into main memory?

A

They must be transferred to main memory because the CPU cannot access them directly

12
Q

Secondary storage devices can be used to transfer what between computers?

A

Stored data

13
Q

What is magnetic storage often used in?

A

Hard disc drives and digital tape drives

14
Q

What does HDD stand for?

A

Hard Disc Drive

15
Q

What are HDDs and digital tape drives often used for?

A

Backup up large computer systems

16
Q

What do magnetic discs consist of?

A

Stacks of non-removable discs coated with magnetic materials

17
Q

How is data encoded with magnetic storage?

A

As opposing magnetic polarities on the surface of the disc. Electromagnets in the read/write heads read and write data

18
Q

With magnetic storage, electromagnets in the read/write heads…

A

read and write data

19
Q

The cost of magnetic storage is very high/low

A

low

20
Q

True/False: Hard disc drives in budget laptops have capacities of at least 1 terabyte

A

True

21
Q

CDs, DVDs and Blu-ray discs are all examples of what type of storage media?

A

Optical

22
Q

List DVD, CDs and Blu-ray discs in the order of how much data they can store up to, from smallest to largest

A

CDs, DVDs and Blu-ray discs

23
Q

What do optical discs use to read and write data?

A

A laser

24
Q

With optical discs, data is encoded as a…

A

series of pits in a spiral track, running from the inside to the outside of the disc

25
Q

True/False: With optical discs, data is is encoded as a series of pits in a spiral track, running from the outside to the inside of the disc

A

False, the pits run from the inside to the outside of the disc, not the other way round

26
Q

CD, DVD and Blu-ray drives write and read data onto discs using…

A

light from lasers

27
Q

Unlike magnetic and optical storage, there are/are no moving parts in solid-state devices

A

are no

28
Q

True/False: There are moving parts in solid state devices

A

False, there are not

29
Q

Solid-state memory is made of what type of memory?

A

Flash memory

30
Q

Flash memory is volatile/non-volatile storage

A

non-volatile

31
Q

True/False: Flash memory can be electrically erased and reprogrammed

A

True

32
Q

Flash memory uses arrays of…

A

transistors (switches)

33
Q

How many states can transistors operate in?

A

2

34
Q

What are the two states that transistors can operate in?

A

0 and 1

35
Q

How are transistors switched between their two states?

A

Using electrical signals

36
Q

How is data encoded with flash memory?

A

As sets of binary digits

37
Q

True/False: 8 GB of solid-state storage require 32 billion transistors

A

True

38
Q

In what devices is solid-state memory used for data storage?

A

Portable devices such as cameras and mobile phones

39
Q

What does SSD stand for?

A

Solid State Drive

40
Q

True/False: SSDs can provide secondary storage instead of magnetic discs

A

True

41
Q

What does SD stand for?

A

Secure digital

42
Q

In what devices are SD and microSD cards used?

A

Portable devices such as phones, cameras and tablets

43
Q

USB flash drives are convenient compact forms of flash memory for…

A

sharing and transferring data

44
Q

The different storage devices have different/the same properties

A

different

45
Q

What is the capacity of magnetic drives like?

A

Very large

46
Q

What is the capacity of optical drives like?

A

Low

47
Q

What is the capacity of solid state drives like

A

Moderate

48
Q

What is the speed of magnetic drives like?

A

Fast

49
Q

Why is magnetic storage fast?

A

Data can be read instantly from any part of the disc and can find and supply required data in milliseconds

50
Q

What is the speed of optical drives like?

A

Slow

51
Q

What is the speed of solid state drives like?

A

Very fast - can access data in nanoseconds

52
Q

What is the cost of magnetic drives like?

A

Very low

53
Q

Magnetic drives storing terabytes of data are common in…

A

most home computers

54
Q

What is the cost of optical drives like?

A

Very low

55
Q

What is the cost of solid state drives like?

A

More expensive than magnetic drives and optical devices

56
Q

Solid state storage is relatively old/new technology

A

new

57
Q

As solid state storage is developed, storage capacity is rapidly increasing/decreasing and the cost is increasing/decreasing

A

increasing, decreasing

58
Q

The different secondary storage each have benefits and drawbacks depending on…

A

the situation

59
Q

What is the portability of magnetic drives like?

A

Not very portable

60
Q

Why are magnetic drives not very portable?

A

Physical knocks may cause the read/write heads to hit the discs and corrupt data

61
Q

How portable are optical storage devices?

A

More portable than a hard disc but discs are relatively large

62
Q

How portable is solid-state storage?

A

Very portable. Small solid-state storage devices can be fitted inside cameras and mobile phones

63
Q

What is the durability of magnetic drives like?

A

Very durable

64
Q

What is the durability of optical storage like?

A

Low because they are easily scratched and data can be corrupted

65
Q

Data stored on optical devices can/cannot be overwritten

A

cannot

66
Q

With data stored on optical devices, what happens over time?

A

It can degrade

67
Q

What is the durability of solid state devices like?

A

There is a limited number of erase/write cycles

68
Q

There is a limited/unlimited amount of erase/write cycles with solid-state storage

A

limited

69
Q

How reliable is magnetic storage?

A

Very reliable

70
Q

How reliable is optical storage?

A

Very reliable if they are not scratched

71
Q

How reliable is solid state storage?

A

Very reliable and data is not affected by magnetic fields (as they are in magnetic drives)

72
Q

True/False: Data in magnetic drives can be affected by magnetic fields

A

True

73
Q

True/False: Data in solid state storage can be affected by magnetic fields

A

False

74
Q

List 3 benefits of magnetic storage

A

Any 3 from very large capacity, fast, very low cost, very durable and very reliable

75
Q

What is the disadvantage of magnetic storage?

A

It is not very portable as physical knocks may cause the read/write heads to hit the discs and corrupt data

76
Q

List 2 benefits of optical storage

A

Any 2 from it is very reliable, more portable than a hard disc drive and very low cost

77
Q

Give 2 disadvantages of optical storage

A

Any 2 from low capacity, slow and not very durable as easily scratched and data can be corrupted

78
Q

List 3 benefits of solid state storage

A

Any 3 from very portable, very reliable, very fast and pretty good capacity & durability

79
Q

What is the disadvantage of solid state storage?

A

It is very expensive