Storage

1. What is Storage?
 Holds data, instructions, and information
needed for future use.
 Storage Medium- is a physical item which a
computer stores information, data, and
instructions. ( also called secondary storage)
 Ex: Floppy disks, Zip disks, CD’s and DVD’s,
tape, and PC cards.
 Storage requirements for the different users
will vary greatly

2. Capacity of storage media
 Capacity- is
the amount of
information or
the number
of bytes a
storage
medium can
hold
Storage Term Estimated
Number of
bytes
Kilobyte (KB) 1 thousand
Megabyte (MB) 1 million
Gigabyte (GB) 1 billion
Terabyte (TB) 1 trillion
Petabyte (PB) 1 quadrillion
Zettabyte (ZB) 1 sextillion
Yottabyte (YB) 1 septillion

3. Terminology
 Storage device- the computer hardware that records and retrieves
items to and from storage media
 Writing- the process of transferring data, instructions, and
information from memory to a storage medium
 Reading- the process of transferring items from a storage medium
into memory
 Access time- (1) amount of time it takes a storage device to locate
an item on a storage medium or (2) the time required to deliver an
item from memory to the processor
 Transfer rate- is the speed with witch data, instructions, and
information transfer to and from a device

4. Floppy disk
 -also called the
diskette
 -portable,
inexpensive storage
medium that is thin
flexible
 -also has a
magnetic coating
enclosed in square
shape plastic shell

5. Floppy disk continued
 An average floppy disk can store up to
500 double spaced pages of text
.They can also store photographs, or
small audio files

6. Floppy disk drives
 - is a device that
reads from and
writes on a floppy
disk.
 External floppy
drive- the drive is a
separate device
with a cable that
plugs into your PC

7. Key Terms
 Density- is the number of bytes in an
area on a storage medium
 Downward compatible- they can
recognize and use earlier media
 Shutter- the metal piece on the floppy
disk
- The average time for a floppy disk to
locate an item is 1/12 of a second

8. Characteristics of a
Floppy Disk
 Floppy disk is a type of magnetic
media that allows people to read and
write on a disk over and over.
 Magnetic Media- use magnetic
particles to store data, instructions,
and information on a disk surface.

9. Continued..
 Track- a narrow
recording band that
forms a full circle
on the surface of
the disk
 Sector- is the pie
shaped figure
 80 tracks,18 sectors

10. High-Density Floppy Disk
Capacity 1.44mb
Slides 2
Tracks 80
Sectors per Track 18
Bytes per sector 512
Sectors per disk 2880

11. CDs and DVDs
 Are types of optical
storage media that
consists of a flat,
round, portable disc
made of metal
plastic and lacquer.
 Store software,
data, digital
photographs,
movies, and music

12. Characteristics of CDs and
DVDs
 Are not magnetic media, instead they
are optical media that store items such
as data and instructions
 Uses microscopic pits (indentations)
and flat areas that are in the middle
layer of the disc

13. How a CDs and DVDs are
read
 A high powered laser light creates the pits.
 A lower powered laser lights reads items from the
disc by deflecting light through the bottom of the
disc, which is usually gold or silver
 The reflected light is converted into a series of bits
the computer can process
 A land causes the light to reflect, which is read as
binary digit 1.
 Pits absorb the light; this absence of light is read as
binary digit 0.
 Items are commonly store items in a single track
that spirals form the center to the outside edges of
the disc

14. Care of CDs and DVDs
 Never bend a disc; it may break
 If a disc becomes warped or if its surface is
scratched, the data on the disc may be
unreadable
 Exposing to extreme temperatures or
humidity could cause them to warp. The
ideal temperature is 50-70 degrees
 Stacking discs, touching the undersides or
exposing them to any type of contaminant
may scratch it
 Best place to store the CD or DVD is in the

15. CD-ROMs
 Is used for storing
data, instructions
and information in
addition to audio
and video
 Can only read the
content on the
discs, meaning that
they cant be erased
 A typical CD-ROM
can hold from 650
MB to 1GB of data

16. Picture CDs and Photo
CDs
 Is a small data CD that
stores up to one role of
film using a jpg file
format
 Picture CD usually is
1024x1536 pixels
 The cost of a picture
CD is about 10 dollars
per role of film
 Stores multiple rolls of
film using the Image
Pac or PCD
 Designed for
commercial and
professional users
 Resolutions ranging
from 128x192 to
4096x6144 pixels
 Store images from
35mm film, negatives,
slides and scanned

17. CD-Rs and CD-RWs
 Multi session CD which
user put there own
information on to
 To be able to write on
the CD-R you need a
CD-R drive to burn the
CD
 Has a speed of 40x or
more
 CD-RW is a rewritable
CD that can be erased.
 Is much like a floppy
disc
 Only down fall is that
the more it is erased
the more faulty the CD
becomes
 The CD-RW drive has
a speed of 52x or more

18. DVD-ROMs
 DVD stands for digital
versatile disc or digital
video disc
 Can store up from 4.7GB to
17 GB the storing capacity
has more than enough to
hold a telephone book
containing every resident in
the United States
 The goal of the DVD
technology is to meet the
needs for home
entertainment, computer
usage and business data
 DVD-ROM players can read
up to speeds 48x or more
 Look just like the CD-ROM
and sometimes are easily
confused
 First involves making the
disc denser by packing the
pits closer together
 Second involves using two
layers of pits. For this to
work the lower layer of pits
is semitransparent so the
laser can be read through
the upper level. This
technique doubles the
storage capacity of the disc
 Finally some discs are
double sided and need to
turn it over when you are
done with the one side

19. DVD-ROM Storage
Capacities
Sides Layers Storage Capacities
1 1 4.7 GB
1 2 8.5 GB
2 1 9.4 GB
2 2 17 GB

20. TAPE
 Tape is a magnetically coated ribbon
of plastic capable of storing large
amounts of data and information
at a low cost.
 Tape is no longer used for storage
purposes; instead, most home
users and businesses use tape
for long-term storage and
background.

21. TAPE DRIVE
 Comparable to a tape recorder.
 Today’s computers use tape cartridges.
Tape cartridges are small, rectangular, plastic
housings for tape.
They are slightly larger than an audio-cassette tape.
On larger computers, tape cartridges are mounted on
a separate cabinet called a tape library.
 Reads and writes data and information on a tape.
 Transfer rate of tape drives range from 500 KBps to 1
MBps.
 To access a certain piece of data, you must forward or
rewind the tape.

22. PC CARDS
 A thin, credit-card-sized device that fits
into a PC Card slot
 Add storage, additional memory,
fax/modem, networking, sound, and
other capabilities
 Commonly used in notebook computers
 They are available in three different sizes
according to thickness- Types I, II, III.
 Cards that house a hard disk have storage
capacities of up to 5 GB

23. MINI MOBILE STORAGE
MEDIA
 PDAs, digital cameras, music players, and
smart phones are devices that provide the
user with instant access to technology
 Because they have limited internal storage,
they require these mini mobile storage
devices to store digital images, music, or
documents
 Most are no larger than a postage stamp

24. CompactFlash
 Storage capacity is
16MB to 1 GB
– Flash memory card
– Used for digital
camera, PDAs,
notebook computers,
printers, music
players, cell phones

25. Secure Digital
 16 MB to 256 MB
 Flash memory card
 Used for digital
cameras, PDAs, cell
phones, digital
video cameras, car
navigation systems,
e-books

26. Memory Stick
 16 MB to 128 MB
 Flash memory card
 Used for digital cameras, notebook
computers, photo printers

27. Microdrive
 1 GB
 Magnetic media
 Digital cameras,
PDAs, music
players, notebook
computers, video
cameras

28. USBDrive
 32 MB to 2 GB
 Flash memory card
 Plugs into any USB
port to function as
a mini hard disk

29. SMART CARD
 Similar in size to a credit card or ATM
card
 Stores data on a thin microprocessor
embedded in the card
 Contain processor and have input,
output, and storage capabilities

30. MICROFILM AND
MICROFICHE
 Store microscopic images of documents on
roll or sheet film
 Microfilm is a 100- 215 foot roll of film
 Microfiche is a small sheet of film, usually
about 4 inches by 6 inches
 A computer output microfilm is the device
that records the images on the film
 Libraries use these to store back issues of
newspapers, magazines, and genealogy
records