Chapter 6 - Storage devices Flashcards Preview

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Flashcards in Chapter 6 - Storage devices Deck (53)
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1
Q

What are the 2 types of primary storage?

A

» RAM and ROM

2
Q

What is primary memory?

A

» The component of the computer that holds data,programs, and instructions that are currently in use

3
Q

What is RAM?

A

» Volatile peice of memory that holds programs and instructions that are currently in use

4
Q

What is ROM?

A

» A non-volatile piece of memory that holds the bootloader - such as the BIOS

5
Q

What are the 4 features of RAM?

A

» It is Volatile
» Can be read from or written to
» Stores the parts of the operating system, programs and data that are currently in use by the computer
» Larger capacity then ROM

6
Q

What are the 3 features of ROM?

A

» It is non-volatile
» It is read-only
» Often used to store the computer’s boot prgoram

7
Q

What does RAM stand for?

A

» Random access memory

8
Q

What does ROM stand for?

A

» Read-only memory

9
Q

What is the definition of volatile?

A

» It means that it loses its contents when electrical power is lost

10
Q

What is virtual memory
?

A

» When the computer’s RAM may not be not large enough to store all these programs
» Hard disk is used as an extension of memory

11
Q

Where is virtual memory held?

A

» On the hard disk

12
Q

What are the benefits of virtual memory?

A

» Reduces the need of phyisical hardware increasing memory
» Storage can be backed up - people around the world can access data
» Allows more programs to be run

12
Q

When is virtual memory used?

A

» When there is an insufficient amount of RAM
» Data is moved to RAM which is currently not in use, moved back to RAM when needed by the computer

13
Q

What are the disadvantages of virtual memory?

A

» Very slow
» Can cause disk thrashing

14
Q

Which is faster secondary storage or primary memory?

A

» Primary memory

15
Q

Why is secondary storage needed?

A

» To keep programs and data indefinitely

16
Q

What are the 3 types of storage devices?

A

» Magnetic
» Optical
» Flash

17
Q

What is the purpose of toggling a state without power?

A

» To represent either 1(which is on)
» To represent either 0(which is off)

18
Q

What are 2 examples of magnetic storage?

A

» Hard disk drive
» Magnetic tape

19
Q

How does a hard disk work?

A

» Rotating platters coated with magnetic material
» Ferrious iron particles on the disc are polarise to become either a north or south state - represents 0 or 1
» Disk divided into cocentric circles - divided into sectors
» Like an old record player - moves around at 10000RPM to access diferent sectors

20
Q

How is data read from or written to in a hard disk?

A

» As it passses under the drive head

21
Q

How do magnetic storages mainly work?

A

» Uses a magnetisable material. Patterns of magnetisation are then used to repreent binary sequences

22
Q

What are the advantages of Magnetic storage?

A

» Fairly cheap
» High in capacity

23
Q

What are the disadvantages of megnetic storage?

A

» Susceptible to damage if dropped
» Vunerable to magnetic fields - strong magnetic filed may erase the data
» Very slow compared to SSD
» Not portable - movements can cause them to malfunction
» Consume more power then flash media

24
Q

What are the 3 different formats that Optical disc come in?

A

» CD - ROM - read only
» CD -R - recordable
» CD-RW - rewritable

25
Q

What does CD-R mean?

A

» Can be written to once

25
Q

What does CD-RW mean?

A

» Can be read to and written to many times

26
Q

How does an optical disk work?

A

» Using a high powered laser to burn sections of the surface, which represents 1s and 0s

27
Q

What are 3 examples of Optical storage?

A

» Compact disc (CD)
» Digital versatile disc (DV)
» Blu-ray disc

28
Q

How much data does a CD-ROM usually hold?

A

» 700MB of data

29
Q

How much data can a Blu-ray disc hold?

A

» 50GB

30
Q

How come Blu-ray disk hold much greater storage then CD-ROM despite being the same CD size?

A

» The shorter the wavelength of the laser - creates much smaller pits
» Enabling a much greater number to fit in the same space

31
Q

What is CD-ROM?

A

» Data cannot be overwritten

32
Q

What are the advantages of Optical storage?

A

» Cheap
» Portable

33
Q

What are the disadvantages of Optical storage?

A

» Easily damaged due to scratching
» Has a much lower capacity compared with other storage devices

34
Q

How does flash memory work?

A

» Specital type of read only memory that uses electronic circuits to represent data

35
Q

What are the advantages of flash devices?

A

» Very fast
» Robust
» Durable
» Low power consumption

36
Q

What are the disadvantages of flash memory?

A

» Expensive
» Sometimes have a certain numer of read/write times

37
Q

What are 3 examples of flash memory?

A

» USB memory stick
» Camera memory card - Micro SD card
» Solid state drive

38
Q

What comparison factors do storaged devices compare on?

A

» Speed
» Durability
» Cost
» Capacity
» Portability
» Robustness

39
Q

How many bits are in 1 nibble?

A

4 bits

40
Q

How many bits are there in 1 byte?

A

» 8 bits

41
Q

How many bytes are there in 1KB?

A

» 1000

42
Q

How many kilobytes are there in a Megabyte?

A

» 1000

43
Q

Why are Solid state drives replaceing Hard disk drives?

A

» SSDs are ligher - so much more suitable for portability
» Data access is faster
» Less power consumption - more energy efficient

44
Q

What is the typical size for a CD?

A

» 650MB

45
Q

What is the typical size for a DVD?

A

» 4.7GB

46
Q

What is the typical size for a Bluray?

A

» 25 - 100GB

47
Q

What is the typical size for a HDD?

A

» 1-20TB

48
Q

What is the typical size for a SSD?

A

» 500GB-5TB

49
Q

What is the typical storage for a magnetic tape?

A

» 10-30GB

50
Q

What is the typical size for a USB flash drive?

A

» 16GB- 1TB

51
Q

What is firmware?

A

» The phyiscal hardware inside the computer

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