2. Magnetic Devices – Floppy Disk and
Drives
HOW DOES IT WORK?
When inserted into a drive, the
magnetic tape is spun around WHAT IS IT USED FOR?
rapidly, much like a CD. A floppy disk drive used in
While spinning, the read/write computers for data transfer,
head of the disk stops at the storage and backup of small
empty track on the disk. The amounts of data, as well as
computer, before sending any installation of programs and
information to the disk, quickly driver updates.
checks for things like system A floppy disk drive accesses
stability and whether or not the data recorded on small,
necessary space is free on the removable diskettes
disk. such as floppy
disks.
3. Magnetic Devices – Floppy Disk and
Drives
Advantages Disadvantages
It is really cheap. Easily destroyed by dust and dirt or
magnetic fields. (If you put the disk next
to anything magnetic, it could wipe
everything off.
The data is write protected. Write Accessing data would be very slow.
protection prevents the data from being
easily destroyed.
It was easy to transfer data from one Storage capacity was limited to only 1.44
computer to the next. MB. (Cannot have full length songs or
have pictures taken on digital cameras
today.
4. Magnetic Devices – Hard Drives
HOW DOES IT WORK?
WHAT IS IT USED FOR?
The hard drive is what a
computer uses to store all of its
data and programs.
5. Magnetic Devices – Hard Drives
Advantages Disadvantages
Stores and retrieves data much faster Hard disks eventually fail which stops
than a floppy disk or CD-ROM. the computer from working.
Usually comes inside of the computer The disk is fixed inside the computer and
already for you. cannot easily be transferred to another
computer.
Large storage capacity. A crash could lead to the lose of
everything on that hard drive.
6. Optical Drives – CD ROM
HOW DOES IT WORK?
Data is recorded onto a CD in
a clockwise spiral from the WHAT IS IT USED FOR?
centre. Its recorded and read in It is used too store music,
a series of lands and pits. Any games, programs, installation
land that the laser hits is CDs, multimedia applications,
reflected to the read head and is video and images.
recorded as a 1 or a 0. They are
counted in groups of 14 and
then converted into standard 8-
digit data.
7. Optical Drives – CD ROM
Advantages Disadvantages
It is easily transportable and is The data can also be easily destroyed
compatible with any other PC or laptop . simply by breaking or cutting the CD.
The data can also be easily destroyed Once created the data cannot be
simply by breaking or cutting the CD. changed or updated.
It can be protected so that the data It can easily be lost or stolen.
won't be erased by accident.
8. Optical Drives – CD-R
HOW DOES IT WORK?
A CD-R disc needs to allow the
drive to write data onto the WHAT IS IT USED FOR?
disc. For a CD-R disk to work, To store recorded data.
there must be a way for a laser Music, voice records. Etc.
to create a non-reflective area
on the disc. A CD-R disc
therefore has an extra layer that
the laser can modify.
9. Optical Drives – CD-R
Advantages Disadvantages
They are cheap and fast. Can only record on it once.
Is suitable for applications that requires Can only store up to around 700mb of
‘burning of data’. data.
10. Optical Drives – CD-RW
HOW DOES IT WORK?
A clear dye layer covers the CD's
mirror. A write laser heats up WHAT IS IT USED FOR?
the dye layer enough to make it Allows data, such as music,
opaque. The read laser in a CD voice records etc., to be stored
player senses the difference on the disk over and over again.
between clear dye and opaque
dye the same way it senses
bumps -- it picks up on the
difference in reflectivity.
11. Optical Drives – CD-RW
Advantages Disadvantages
Can read discs made by different CD-R CD-RW’s media can be written/erased
and CD-RW devices. over and over.
CD-RW’s media can be written/erased CD-RW drives are slower than CD-R
over and over. drives.
CD-RW devices can write to both CD-R Most players don’t work with CD-RW’s.
and CD-RW media.
12. Optical Drives – DVD
HOW DOES IT WORK?
A laser is used to read and store
data onto the disk. WHAT IS IT USED FOR?
Storing multimedia files such as
MP3, digital images and video
clips.
13. Optical Drives – DVD
Advantages Disadvantages
They are cheap and fast. Easily destroyed/damaged.
DVD drives can read CD’s. DVD’s do not work in CD drives.
The sound and picture quality is Cannot put data on it more than once.
amazing.
14. Optical Drives – DVD ROM
HOW DOES IT WORK?
DVD-ROMs has an optical path,
a drive head which holds the WHAT IS IT USED FOR?
laser, a lens and devices called For the distribution of movies
photodiodes, which read the where you can only read data
light bouncing from the DVD's off of the disk. It can also be
pits. used to read the data off of a
CD.
15. Optical Drives – DVD ROM
Advantages Disadvantages
Cannot steal because you need to right Can be easily broken.
drive to read the data on the DVD ROM.
Can hold up to 700MB of data which is It cannot put data more than once.
74 minutes of audio.
16. Optical Drives – DVD + RW
HOW DOES IT WORK?
WHAT IS IT USED FOR?
To write and read data from a
DVD. They are also able to be
written to and not just read
from.
17. Optical Drives – DVD + RW
Advantages Disadvantages
It is about 4.7 GB. They can be expensive.
It is rewritable. Many players can not read DVD RW’s.
N/A Because they are rewritable, the data
can easily be deleted.
18. Magnetic Tape
HOW DOES IT WORK?
A plastic film tape is coated with
an iron oxide coating. That tape WHAT IS IT USED FOR?
is passed by and in contact with To store the data such sound,
a recording head, that consists video and recordings, on a
of a metal core with wire plastic magnetic coated tape
windings on it. which is stored on a reel.
19. Magnetic Tape
Advantages Disadvantages
Can be set up to work over night or Takes ages for the data to be found on
through the weekend. the tape. Could be quite slow.
Really, really cheap. The data can be corrupted if place next
to anything magnetic.
Can store large amounts. Up to Needs a special type of equipment to
1Terabyte. record and read the data.
20. Flash/Pen Drives
HOW DOES IT WORK?
A flash drive consists of a PCB
that is, a printed circuit board. It WHAT IS IT USED FOR?
is covered in a plastic or rubber To store data such a
casing, which makes it sturdy. photographs and music. Can be
Once plugged in, a flash drive used for internal storage on
enters the emulation mode tablet computers that have no
which means it emulates a hard room for the normal hard drive.
drive thereafter.
21. Flash/Pen Drives
Advantages Disadvantages
Light weight. So small it is easily misplaced or stolen
without knowing.
Has a large capacity storage. Fast access.
Can be used as a backup. Do not have a high transfer rate as
magnetic hard disk drives.
Flash memory is non-volatile. A virus can be easily passed from one
computer to the next.
22. Memory Card Drives & Memory Cards
HOW DOES IT WORK?
WHAT IS IT USED FOR?
Store photographs and other
data, usually on digital cameras.
23. Memory Card Drives & Memory Cards
Advantages Disadvantages
Many computers and printers have Cannot be attached or read on the
drives that will read the data on computer without proper hardware.
different sized memory cards.
It’s small. It can sometimes run slow.
Can be used in digital cameras, mobile Can be quite expensive.
phones and MP3 players.
