Storage Devices and Media

Question 1

What is magnetic tape?

Answer 1

Is a very thin strip of plastic which is coated in a magnetic layer (iron oxide)- it reads, writes and stores data

Question 2

What are the uses of magnetic tape storage?

Answer 2

• Use in applications where batch processing is used (e.g. Clearing bank cheques, utility billing and producing pay slips
• Used as a backup media where vast amounts of data needs to be stored
• Used in long-term archiving of data

Question 3

What are the advantages and disadvantages of magnetic tape?

Answer 3

Advantages:
- They are generally less expensive than the equivalent hard disk drive for high volumes of data
- Huge data storage capacities
- The data transfer rate is fast
Disadvantages:
- Very SLOW access times
- When updating, another tape is needed to store the final updated version
- They are affected by magnetic fields- a strong magnet can corrupt data stored on the tape

Question 4

Define Data Transfer Rate.

Answer 4

Is the rate at which data can be sent from a storage device to a computer.

Question 5

Define Data Access Time.

Answer 5

Is the time it takes to locate specific data stored on the storage media.

Question 6

What are the uses of a Hard Disk Drive?

Answer 6

• To store the OPERATING systems, system software and working data/files
• Storing applications software
• Used in real-time systems e.g. Robots
• Used in file servers for computer networks

Question 7

What are the advantages and disadvantages of Hard Disk Drives?

Answer 7

Advantages:
- They have a very fast data transfer rate
- Large memory capacities
Disadvantages:
- Fairly easily damaged
- Many moving parts which can affect their whole ability in general
- Their read/write operation can be quit noisy when compared to Solid-state drives (SSD)

Question 8

How does a HDD work?

Answer 8

• Actuators are used to move the read/write heads
• A read/write arm swings the read/write head back and forth across the platter; the platter is rotating at up to 10,000 rpm (revolutions per minute)
• Each read/write head contains a tiny magnet which allows the data on the platter to be read
• Platters are made from glass which are coated in iron oxide
• There are two read/write heads per platter
• Data is stored in circular tracks- each track is broken into sectors
• When the computer wants to store new data it looks at the file allocation table to see which sectors are free and moves the head to that location

Question 9

How is a portable HDD different to a normal HDD?

Answer 9

Portable external hard drives are smaller and lighter than desktop drives.

Question 10

When are portable HDDs used?

Answer 10

Used for transport as well as backup and additional storage, portable hard drives rival the capacity

Question 11

What are the advantages and disadvantages of a portable HDD?

Answer 11

Advantages:
- The data access time and data transfer rate are very rate
- They have a large memory capacity
- They can be used as method of transferring information between computers
Disadvantages:
- They can be easily damaged
- Data transfer rate is not as fast for fixed hard drives

Question 12

Define latency.

Answer 12

Network latency is the delay in network communication. It shows the time that data takes to transfer across the network.

Question 13

What do we mean by Optical Media?

Answer 13

Discs (CDs, DVDS and Blue Ray) that are read by lasers

Question 14

What do the following mean:
ROM ?
RW ?
R ?

Answer 14

ROM- Read Only Memory
RW- Can be written to or read from many times
R- Wite once only

Question 15

What is the typical capacity and uses of DVD-R and CD-R?

Answer 15

CD-R: 700 MB
DVD-R: 4.7GB
- Home recordings of music (CD-R) and films (DVD-R)
- Used to store data to be kept for later use or to be transferred to another computer

Question 16

What are the advantages and disadvantages of DVD-R and CD-R?

Answer 16

Advantages:
- Cheaper medium than RW disks
- Once burned( and finalised) they behave like a ROM
Disadvantages:
- Can be only recorded once; if an error occurs then the disk has to be thrown away
- Not all CD/DVD players can read CD-R/DVD-R

Question 17

What is the capacity and uses of CD-RW / DVD-RW?

Answer 17

CD-RW: 700 MB
- Used in CCTV systems
- Can be used as a backup device for files and data
- Used to record television programmes which can be recorded over, time and time again

Question 18

What are the advantages and disadvantages of CD-RW / DVD-RW?

Answer 18

Advantages:
- Can be written over many times
- Can use different file formats each time it is used
- Not as wasteful as R format because the files, data can be added at a later stage
Disadvantages:
- Can be relatively expensive media
- Possible to accidentally overwrite data

Question 19

What are is the capacity storage and the uses of CD-ROM/DVD-ROM?

Answer 19

650MB
- Permanent method of data storage
- Used to store music files and to store software
- DVD-ROM has much larger storage and is used in store films

Question 20

What are the advantages and disadvantages?

Answer 20

Advantages:
They are less expensive than hard disk drive systems
Disadvantages:
- The data transfer rate and access time is slower than for hard disk drives

Question 21

What are is the capacity storage and the uses of Blu-ray?

Answer 21

25-50 GB
- Home video consoles
- Storing and playing back movies
- For data storage in computers

Question 22

What are the advantages and disadvantages of Blu-ray?

Answer 22

Advantages:
- Very large storage capacity
- Very fast data transfer rate
- The data access speed is also greater than with other typical media
- Automatically come with secure encryption code
Disadvantages:
- Relatively expensive discs
- Encryption problems

Question 23

What is a Solid state drive (SSD)?

Answer 23

A solid-state drive (SSD) is a new generation of storage device used in computers. SSDs store data using flash-based memory, which is much faster than the traditional hard disks

Question 24

What are the advantages of SSD compared to HDD?

Answer 24

• They are more reliable depending on how it is used
• They are considerably lighter- more portable and suitable for mobile phones
• They do not have to ‘get up to speed’ - you have to wait for them to start spinning and get up to operational speed before they work properly
• They have a lower power consumption (as there are no moving parts)
• They run much cooler than HDDs
• Because of no moving parts, they are very thin and more durable so do not break easily
• SSD data access time is much quicker compared to a HDD
• Data transfer speed for SSDs is also much faster than for HDDs
• Suitable for mobile devices as they have lower power consumption and no moving parts
• Not as affected to magnetic interference

Question 25

What is another name for a pen drive?

Answer 25

Memory sticks

Question 26

What are the disadvantages of SSD?

Answer 26

The longevity of the technology: most SSD storage devices are rated at only 20 GB. For this reason SSDs were not used in large servers e.g. write large operation take place everyday. as to take place everyday, more expensive per megabyte, megabyte, terabyte when compared to HDD

Question 27

Give 2 uses of pen drives?

Answer 27

Transporting files between computers or using a backing store. Used as a security device to prevent software piracy

Question 28

What are the advantages of pen drives?

Answer 28

Very compact and portable media

Very robust

Does not need additional software to work on most computers

They are not affected by magnetic fields

Question 29

What are the disadvantages of pen drives?

Answer 29

Cannot write protect the data/files by making it ‘read only.’

Easy to lose

The user needs to be very careful when removing the stick from a computer otherwise it will corrupt the data on the memory stick and make it useless

Question 30

List the 3 types of memory card.

Answer 30

SD - (secure digital card)
The SD card is a type of very small card with a very high-capacity memory. SD
cards are primarily used in portable devices such as digital video recorders,
digital cameras, audio players, smartphones and tablets.

xD - (extreme digital card)
The XO card is a type of removable memory card designed for use in digital
cameras. They can be written to or read from the camera or other suitable XO
card reader (the card readers can often be attached to a computer to allow the
memory card to be read directly).


Cfast - (compactfast card).
A (Fast card is a memory card format which was developed to allow solidstate
technology to be used in a very small portable·device. It has no moving
mechanical parts and does not need a battery to retain data. (Fast cards are primarily use

Question 31

Give 4 uses of memory cards.

Answer 31

Storing photos on digital cameras, Used as mobile phone memory cards, Used in MP3 layers to store music files, Used as a backing store in hand-held computer devices

Question 32

What are the advantages of memory cards?

Answer 32

Very compact

They are very durable because they are solid-state memories

They can hold large amounts of data

Digital devices are able to read and write memory card

Question 33

What are the disadvantages of memory cards?

Answer 33

Expensive per gigabyte of memory when compared to hard disk drives

Have a lower storage capacity than hard disks

Have a finite life, regarding number of times they can be read from wand written to

Memory cards, specifically the micro SD card are the smallest deb=vices available; able to be lost or damaged

Not all computers come with memory card readers built in; have to purchase one

Question 34

Why might optical media become obsolete?

Answer 34

Optical drives tend to take up a lot of space, making computers big and unattractive. Because of the advancement of better data management methods and storage technologies and popularity of streaming surfaces.

Question 35

Why might DVD & Blu Ray players become obsolete?

Answer 35

Many televisions sets are now set up as smart televisions- this means that it is now possible to possibly stream on demand