Secondary storage Device .....

1. Group Name : Infinity
Group Members :
1. DM. Mehedi Hasan Abid (151-15-226)
2. Sajedul Islam (151-15-494)
3. Mokbul Hossain (151-15-469)
4. Radwan Ahmed (151-15-503)
5. Robin Hossain (151-15-475)
6. Tanvir Asad (151-15-223)

2. Topic: Secondary Storage
Objective
 Advantages and disadvantages of secondary storage.
 Idea about secondary storage.
 Types of secondary storage.
 The causes of using secondary storage.

3. What is Secondary Storage?
Secondary storage technology refers to
storage devices and storage media
that are not always directly
accessible by a computer. This differs
from primary storage technology,
such as an internal hard drive,
which is constantly available.
In Computer Science, “Any means of
storing and retrieving data external
to the main computer itself but
accessible to the program.”

4. The Advantages of Secondary Storage
 Secondary storage devices are safe, reliable and permanent.
 High speed storage device.
 Huge volume data are stored.
 Less expensive.
 It is nonvolatile.

5. The Disadvantages of Secondary Storage
 While RAM electronic storage devices are fast, secondary storage devices are
slower because they are electro-mechanical.
 The information on the secondary device has to be first located, then copied and
moved to the primary memory or RAM.
 Takes more time.

6. Types of Secondary Storage
 Magnetic Tape.
 Magnetic Disk.
 Optical Disk.

7. Magnetic Tape:
 Oldest storage device.
 Used for large computer like mainframe
computers.
 Made of plastic coated with magnetic
material.
 Store data permanently.
 Used to read and write data.
 Cost of storing data is expensive.
 Used in reels.
CreatedbyHossainRaju

8. Magnetic Disk:
 A thin circular metal or plastic disk coated
with magnetic material,
 Stored data in the form of magnetic spots,
 A random access device,
 Faster than magnetic tape.
There are three main types of magnetic
disk:
1. Hard Disk
2. Floppy Disk
3. Zip Disk

9. Types of Secondary Storage :
Optical Disk:
 Used LASER technology to read and write data.
 LASER stands for Light Amplification through
Emission of Radiation.
 Laser beam writes on the surface of optical disk by
creating very small holes.
 The presence of hole represents a One.
 Absence of the hole represents a Zero.