Its a presentation on the secondary memory of the computer devices where the details of the each memory devices are described.

1. Secondary Memory
Title of
Presentation

2. 2Prepared For
Shahinur Alam
Assistant Lecturer
Department of Computer Science and Engineering
SN Name ID No
01 Rihab Rahman CONFIDENTIAL
02 Tasnia Tahsin CONFIDENTIAL
03 Kaisary Zaman CONFIDENTIAL
04 Jakia Sultana CONFIDENTIAL
05 Maseat Nahar CONFIDENTIAL
06 Md. Fahad CONFIDENTIAL
Prepared By
Group – The Glorious
27-Jul-192

3. • Introduction
• Classification of secondary memory
• Magnetic Tape
• Magnetic Disk - Hard Disk Drive, Floppy Disk, Zip Disk
• Optical Disk – CDR, CDRW, DVDR, DVDRW, Blue Ray
• Memory Storage Device - Pen drive, Memory Card
• Conclusion
• Q&A
Objectives
27-Jul-19 3Rihab Rahman

4. Introduction
• Memory : Computer memory is any physical device capable of
storing information temporarily or permanently. There are
two types of memory. Such as – Primary Memory and
Secondary Memory.
• Secondary memory is computer memory that is non-volatile
and persistent in nature and is not directly accessed by a
computer/processor. It allows a user to store data that may
be instantly and easily retrieved, transported and used by
applications and services.
• Secondary memory is also known as secondary storage.
27-Jul-19 4Rihab Rahman

5. Classification of Secondary Memory
Secondary
Memory
Sequential Access
Device
Magnetic
Tape
Direct
Access Device
Magnetic
Disk
Hard Disk
Floppy
Disk
Zip Disk
Optical
Disk
CD-R CD-RW
DVD-R DVD-RW
Memory Storage
Device
Pen Drive
Memory
Card
27-Jul-19 5Rihab Rahman

6. Magnetic Tape
❖Oldest storage device
❖Used for large computer
❖Used in Mainframe Computers
❖Made of plastic coated with
magnetic material
❖Used to read and write data
❖Cost of storing data is expensive
❖Used in reels Fig: MagneticTape
27-Jul-19 6Maseat Nahar

7. Magnetic Disk
A magnetic disk is a storage device that uses a
magnetization process to write, rewrite and access data. It
is covered with a magnetic coating and stores data in the
form of tracks, spots and sectors.
There are three main types of magnetic disk:
❖Hard Disk
❖Floppy Disk
❖Zip Disk
27-Jul-19 7Maseat Nahar

8. Hard Disk
❖Usually used as a secondary storage
❖Also called fixed disk
❖Consists of one or more metal Plates
❖Used for long term storage data
Fig: Hard Disk
27-Jul-19 8Maseat Nahar

9. Floppy Disk
❖A small plastic plate coated with
magnetic material.
❖Stored data in magnetic spots.
❖Used to transfer data from
one computer to another
❖Presently used in airlines.
Fig: Floppy Disk
27-Jul-19 9Jakia Sultana

10. Zip Disk
❖ Similar to 3 ½ inch FLOPPY disk.
❖ Can store 100 MB or more data.
❖ Used to read and write data.
Fig: Zip Disk
27-Jul-19 10Jakia Sultana

11. CD-R: CD Recordable or WORM
❖Compact disc recordable.
❖An optical secondary storage device.
❖Invented by SONY and PHILIPS.
❖Also known as a WORM
Write Once Read Many
❖Can store data on it only once.
Fig: CD-R
27-Jul-19 11Jakia Sultana

12. CD-RW: Rewriteable Compact Disk
❖A CD-RW disc is coated with a metal alloy
❖ Can be written to many times.
❖CD-RW drive has a laser that
❖ has three different power settings
❖CD-RW discs usually hold
❖ 74 minutes (650 MB) of data,
❖ although some can hold up to
❖ 80 minutes (700 MB) of data.
Fig: CD-RW
27-Jul-19 12Kaisary Zaman

13. DVD-R: Recordable DigitalVersatile Disk
❖Can store approximately 7 times more data than a CD-ROM
❖Stores around 4.38 GB of data
❖DVD uses light of 650 nm wavelength
❖Access rate is 600 KBps to 1.3 MBps.
27-Jul-19 13
Fig: DVD-R
Kaisary Zaman

14. DVD-RW: Rewriteable DVD
❖Introduced by coalition of corporations
❖Can write data many times by
erasing the old data.
❖Discs need to be blanked before reuse
27-Jul-19 14
Fig: DVD-RW
Md. Fahad

15. Blue Ray
❖ Digital Optical disc data storage format
❖Developed by Blu-ray Disc Association
❖storing hours of video in high definition
❖Used to read and write
❖ single-layer disc and dual-layer disc
27-Jul-19 15
Fig: Blue Ray
Md. Fahad

16. Pen Drive
❖A small piece of equipment that we connect to a computer or
other piece of electronic equipment to copy and store
information.
27-Jul-19 16
Fig: Pen Drive
Tasnia Tahsin

17. Memory Cards
❖A memory card, flash card or
memory cartridge is an electronic
flash memory data storage device
used for storing digital
information.
❖It uses nonvolatile
semiconductor memory to store
data on portable or remote
computing devices. Such data
includes text, pictures, audio and
video.
27-Jul-19 17
Fig: Memory Card
Tasnia Tahsin

18. Conclusion
The primary memory is costly, not a permanent storage
media and has limited capacity. The secondary memory is
the storage other than main memory and used to store
large data, files, system program and the like which are
not continuously required by the CPU.
27-Jul-19 18Tasnia Tahsin