Topic 1.4 of AICT(CIE Syllabus) It contains the description of the secondary storage devices including advantages, disadvantages.

1. Backing Storage Media and Devices
All computer systems require some form of
backing storage to store data permanently for

2. Magnetic
Optical
Solid State
Storage Devices

3. Magnetic Media

4. Magnetic tapes
 Uses
1. In batch-processing
situations, for example
updating banking accounts
with cheques.
2. In utility billing systems
3. Payroll applications
4. Making backups of data

5. Advantages Disadvantages
1. Cheaper bit for bits than using
disks.
1. Access is slow, so uses are limited.
2. Very robust as they are encased in
a cartridge.
2. Updating files requires a new tape
to be created.
3. Easier to remove and keep away
from computer.
4. Data transfer rate is fast.

6. Fixed Hard Disks
 Uses
Fixed hard disks are essential in any
system that requires fast data
access times and fast data transfer
rates:
1. Used in real-time system such as
robotics, rocket launching, etc.
2. Essential in any online system
3. Used in file servers in computer
networks

7. Advantages Disadvantages
1. Data transfer rate is
fast.
1. They are easily
damaged.
2. Data access times are
fast.
3. Have a very large
capacity.

8. Portable Hard Disks
 Uses
1. used as backup media and for
transferring large files from
one location to another.
2. transferring server software
from one network to another.

9. Advantages Disadvantages
1. Data transfer rate is
fast.
1. They are easily
damaged.
2. Data access times are
fast.
2. transfer rates are not as
fast as fixed hard disks
3. Have a very large
capacity.
3. More expensive than
other forms of removable
media such as CDs or DVDs

10. Optical Storage Backing
Media

11. CD ROMs / DVD ROMs
 Uses
1. CD ROMs are used to store music
albums and to provide audio
output in home entertainment
systems.
2. DVD ROMs are mainly used for
storing films, now are
increasingly being used for data
storage.

12. Advantages Disadvantages
1. DVDs hold more data
than CDs.
1. Data transfer rates for CDs
and DVDs are slower than hard
disks.
2. CDs are cheaper than
DVDs.
2. data access times are
longer than for hard disks.
3. Both hold more data than
a floppy disk.
4. Both are cheaper than
hard disks.
5. Both are more robust
than hard disks.

13. CD RWs / DVD RWs
 Uses
1. used for recording television
programs that can be replaced
later
2. used in latest handy cams/video
cameras

14. Advantages Disadvantages
1. Can be used more than
once
1. Their costs make them
impractical for use as
permanent back up media.
2. Different versions of
files can be over written,
thereby virtually
increasing capacity.
2. Files can be overwritten
accidently.

15. CD Rs / DVD Rs
 Uses
1. used for home recordings of
music on CD and films on DVD
2. used for storing and transferring
data from one machine to
another

16. Advantages Disadvantages
1. Cheaper than CD/DVD RWs 1. Can only be recorded on once
2. once burnt, they cannot be
accidently written over.
2. if several versions are
recorded on the disk, takes up
more space than storing on
CD/DVD RWs.
3. not all CD players will read CD
Rs.

17. DVD RAMs
 Uses
1. DVD-RAMs are used for general
data storage
2. used for data archiving, as it lasts
longer than other optical media
3. in some camcorders, they are
used for recording video

18. Advantages Disadvantages
1. have a great capacity
than CDs/DVDs.
1. not compatible with
most DVD players.
2. more durable than
DVDs.
2. more expensive than
other types of DVD media.

19. Blu-Ray Disks
 Uses
1. Mainly used in home video game
consoles.
2. Devices have been developed to
facilitate the playing and
recording of videos.
3. PCs and laptops are being
developed that use blu-ray disk
drives for data storage as well as
playing videos.
4. They are mainly used in many
camcorders.

20. Advantages Disadvantages
1. Store more than other
optical media.
1. Very expensive
compared with other data
storage media.
2. Data transfer rates are
high.
2. Problems are being
faced with the encryption
techniques used to
prevent piracy.
3. Access speeds are
higher with blu-ray
players than with other
optical devices.

21. Minidisks
 Uses
1. Mainly used in music players and
data storage.
Advantages Disadvantages
1. Can be rewritten more
times than other media.
1. Have slower transfer
rates than other disks.
2. More robust than
other optical media.
2. Store less data than
other music players.
3. More expensive than
other portable players.

22. Solid State Backing
Storage

23. Memory Sticks / Pen drives
 Uses
1. Used to transport files and
backup data from computer to
computer.
2. Used by system and network
administrators for carrying
software fixes.

24. Advantages Disadvantages
1. More compact than
equivalent optical or
magnetic media.
1. More expensive per
Gbyte than hard disk
drives.
2. More robust – can
even survive “washing”.
2. Drives cannot be write
protected.
3. Do not need software
drivers to operate.

25. Flash memory cards
 Uses
1. Used for storing photographs in
digital cameras.
2. Used in mobile phones to store
phone numbers, photographs,
etc.
3. Used in MP3 players to store
music.
4. Used as backing storage in many
handheld computers.

26. Advantages Disadvantages
1. More compact than
equivalent optical or
magnetic media.
1. More expensive per
Gbyte than hard disk
drives.
2. Have limited number of
read/write operations.
3. Have lower storage
capacity than hard disk
drives.