Short description about secondary storage device

1. PRESENTATION:
SECONDARY STORAGE DEVICES
WORK BY: GROUP F

2. OBJECTIVES:
• To know about different types of storage devices.
• To know about the capacities of different types of secondary
storage devices.
• To explain about the structure of different types of secondary
storage devices
• To explain the performance characterstics of mass storage devices.

3. SECONDARY STORAGE DEVICE:
Since Primary Storage has limited storage and is not permanent, We use secondary
storage devices such as hard disk, DVD, pen drive, etc. It is slower and cheaper form
of memory and is not accessed by CPU directly. The content in it must first be copied
into the primary storage RAM for CPU to process.
They are used to store large amount of data permanently.
The types of secondary storage devices are:
MAGNETIC DISK FLASH MEMORY OPTICAL DISK

4. A. Floppy disk:
 It is one of the oldest type of secondary storage devices still in use.
 It is a magnetic medium, compared to hard disk it is small in size and
capacity.
 Floppy disk are protective (protected with plastic coating).
 It is used to transfer small type of data from one device to another.
Floppy Disk
Protected with plastic
coating

5. B. Hard Disk:
 It can store large amount of data permanently and provide quick
access to the data.
 It is a non volatile memory i.e. it can store data even if power is
switched off.
 Data are recorded on the tracks and read by using read/write heads.
 A motor rotates the disk at very high speed.
Structure of Hard disk
Hard disk

6. C. Pen Drive:
 It is portable USB ( Universal Serial Bus) flash memory device that can be used to
transfer audio, video and data files from one computer to another.
 It is shaped like a pen and can be connected in computer using USB port.
 Storage capacities of pen drives ranges from MB to GB.
Pen Drives Structure of Pen Drives

7. D. Optical Disk (CDs and DVD):
 They are electronic data storage medium that can be written to and read using a
low powered laser beam.
 They are compact, durable and lightweight.
 They are mainly used to store music, movies and software programmes .
 Storage capacities ranges from MB to GB.[Blue ray disc can hold upto 25 to 50 GB]
CD[Compact Disc] DVD[Digital Versatile Disc] Blue ray disc

8. E. Magnetic tape:
 It is a sequential storage device of computer. It is slow and
sequential flow of data.
 It is coated with magnetic oxide which can be magnetized to
record information as a series of magnetized spots to represent
binary zeroes and ones.
 It is used in mainframes and super computer.
Magnetic Tape

9. F. External Drive:
 It is a hard disc connected outside from a computer via an interface
cable, which allows the external hard drive to communicate with the
computer.
 External hard discs usually are used in addition to internal hard drives
in order to store more data.
External Hard drive
Connections via interface
cable

10. SUMMARY:
From the above explanation, we can conclude that due to lack of high storage
capacities, secondary storage devices are introduced. Secondary storage devices
are not directly connected to the processor but are first copied into the primary
storage RAM for CPU to process. They are introduced to store large amount of
data permanently.
The types of secondary storage devices are:
• Floppy Disk
• Hard Disk
• Magnetic Tape
• Pen Drive/ Memory Card
• Optical Disk
• External Drive