4. INDEX
Introduction
List of Storage Devices
1]Magnetic Tapes
2] Magnetic Disk
3]Floppy Disk
4]Optical Disk
5]Memory card
6]DVD
7]Pendrive/Flash drive
5. INTRODUCTION
Computer data storage, often called storage or
memory, is a technology consisting of computer
components and recording media used to retain digital
data. It is a core function and fundamental component
of computers. The central processing unit (CPU) of a
computer is what manipulates data by performing
computations. In practice, almost all computers use a
storage hierarchy, which puts fast but expensive and
small storage options close to the CPU.
There are three types of storage:
i. Primary Storage
ii. Secondary storage
iii. Tertiary storage
6. TYPES OF STORAGE
Primary Storage
Primary storage, often referred to simply as memory, is the only one
directly accessible to the CPU. The CPU continuously reads
instructions stored there and executes them as required.
Secondary Storage
Secondary storage is not directly accessible by the CPU. The
computer usually uses its input/output channels to access
secondary storage.It don’t loose the data when computer is
powered down.
Tertiary Storage
Tertiary storage, provides a third level of storage. It involves a
robotic mechanism which will mount (insert) and dismount
removable mass storage media into a storage device according to
the system's demands.
7. GDD MAGNETIC TAPES
This storage devices is used where sequential
data and processing is used .The tapes have
high durability power and can be erased and
refused again and again.
Advantages:-
Economical in nature, gives fast
input and output,its reusable,long term storage.
Disadvantages:-Only sequently recording &
accessing.
Inconvenient for storing large number of small
records.
For drives it makes compatibility difficult.
8. STRUCTURE
The tape
is a pastic ribbon
usually
½ inch wide
that is coated on
one side with an iron-
oxide material which
has high quality
and more durable
9. MAGNETIC DISK
It is a memory device in which a number of disk
make a disk pack.The surface of each recording
surfaces in a 6 disk pack.
It’s a read/write disk.
The disk when loaded is drive
at a high number of revolute
And acess is made on surface
when the disk revolve.
There are two types:
1]Hard disk
2]Removable disk
10. ADV. & DISADV. OF MAGNETIC DISKS
Advantages
i. Large capacity
storage.
ii. Reusuable disks.
iii. Have ability to store
data.
Disadvantages
i. Costlier than tapes.
ii. More susceptional to
errors.
11. FLOPPY DISK
Magnetic disk[floppy disk] is also used as an
auxilary storage medium.Its use is limited to small
computer based system.
Advantages :
Floppy disks are-
Compact ,reusable and cheap.
Disadvantages :
Floppy disks are more prone to data loss and it is
difficult to handle
12. STRUCTURE OF FLOPPY DISK
These are normally 3 ½ inch in diameter and with
storage capacity 1.44
MB.They have a plastic
cover which keeps the
whole disk surface covered
and protected when not in
use.
13. OPTICAL DISK
Optical disk are ROM ,pre-recorded by the
manufacturer.The disk is flat round in shape
made up of a resin.
These work under the same
principle that is used for the domestic compact
disk which have become very popular.
They have large capacity and
less error prone.
But these are having
high cost and are non
reusable
15. DVD
Digital Video Disk are new type of CD-ROMs that
hold a minimum of 4.7 GB almost 2 hrs recording
and have normal size of 4.7 inches.
The Digital sound can be seperated into discrete
channels making surrounding sound possible.
Advantages :- Good storage capacity,reusable.
Disadvantages:-
i. Limitated memory
ii. Delicate structure
16. MEMORY CARDS/FLASH CARD
A memory card or flash card is an electronic flash
memory data storage device used for storing digital
information. They are commonly used in many
electronic devices, including digital cameras, mobile
phones, laptop computers, MP3 players and video
game consoles. They are small in size.
Adv. :-Re-recordable, and able to retain data
without power.
Disadv. :- Limitated memory and
17. DIFFERENT TYPE OF MEMORY CARD
IT IS AVAILABLE IN 2GB,4GM,8GB,16GB,32GB
AND SO ON.
18. PEN/FLASH DRIVE
Pen drive is one of those plug and play devices.It
does not need a Data stored on flash drives is
impervious to mechanical shock, magnetic
fields, scratches and dust. These properties make
them suitable for transporting data from place to
place and keeping the data readily at hand.software
to use.
Advantages:-Use a little power,most capacities are
small and light.
Disadvantages:-more expensive and available
capacity is increasing with time.
