What is Storage?
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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
Capacity of storage media
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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
Terminology
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Storage device- the computer hardware that records and retrieves
items to and from storage media
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Writing- the process of transferring data, instructions, and
information from memory to a storage medium
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Reading- the process of transferring items from a storage medium
into memory
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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
Floppy disk
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-also called the
diskette
-portable,
inexpensive storage
medium that is thin
flexible
-also has a
magnetic coating
enclosed in square
shape plastic shell
Floppy disk continued
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An average floppy disk can store up to
500 double spaced pages of text
.
They can also store photographs, or
small audio files
Floppy disk drives
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- 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
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
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Characteristics of a
Floppy Disk
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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.
Continued..
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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
High-Density Floppy Disk
Capacity
1.44mb
Slides
2
Tracks
80
Sectors per Track
18
Bytes per sector
512
Sectors per disk
2880
CDs and DVDs
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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
Characteristics of CDs and
DVDs
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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
How a CDs and DVDs are
read
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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
Care of CDs and DVDs
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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
CD-ROMs
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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
Picture CDs and Photo
CDs
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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
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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
CD-Rs and CD-RWs
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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
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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
DVD-ROMs
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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
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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
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
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.
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TAPE DRIVE
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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.
PC CARDS
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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
MINI MOBILE STORAGE
MEDIA
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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
CompactFlash
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Storage capacity is
16MB to 1 GB
– Flash memory card
– Used for digital
camera, PDAs,
notebook computers,
printers, music
players, cell phones
Secure Digital
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16 MB to 256 MB
Flash memory card
Used for digital
cameras, PDAs, cell
phones, digital
video cameras, car
navigation systems,
e-books
Memory Stick
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16 MB to 128 MB
Flash memory card
Used for digital cameras, notebook
computers, photo printers
Microdrive
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1 GB
Magnetic media
Digital cameras,
PDAs, music
players, notebook
computers, video
cameras
USBDrive
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32 MB to 2 GB
Flash memory card
Plugs into any USB
port to function as
a mini hard disk
SMART CARD
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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
MICROFILM AND
MICROFICHE
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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