This document provides an overview of primary and secondary storage. It discusses various types of secondary storage devices including magnetic storage devices like tapes, floppy disks, and hard disks which use magnetically coated surfaces. Optical storage devices are also covered, specifically CDs, DVDs, and Blu-ray discs which use reflected light to represent binary data. The document concludes with a brief description of solid state storage using integrated circuits.

1. An Overview...
MBA/Kujur/SSD

2. Storage
 Primary storage
 Volatile
 Temporary
 It loses all its contents
when power to the system
unit is switched off.
 Secondary storage
 Nonvolatile
 Permanent
 Writing : is the
process of saving
information.
 Reading: is the
process of accessing
information.
MBA/Kujur/SSD

3. Primary Storage
 RAM (Random Access Memory)
 ROM (Read Only Memory)
 PROM (Programmable ROM)
 EPROM (Erasable PROM)
 EEPROM (Electrically Erasable PROM)
MBA/Kujur/SSD RAM

4. SECONDARY STORAGE
DEVICES
MBA/Kujur/SSD
The physical component on which the data can be
written (stored) and read from (accessed), called as
storage devices.

5. MAGNETIC STORAGE
DEVICES
MBA/Kujur/SSD
The surface of the magnetic tape, floppy disk and
hard disc are all coated with a magnetically sensitive
material (iron oxide) which reacts to the magnetic
field.
 Magnetic Tapes
 Floppy Disks
 Hard Disks

6. MAGNETIC TAPE
 Sequentially accessed and processed
 Plastic ribbon, ½ inch wide & 50-2400 ft long
 Horizontal rows called tracks or channels
 Magnetised - 1s & Non-magnetised – 0s
 Magnetic material – Iron oxide/ Chromium dioxide
MBA/Kujur/SSD
Tracks

7. FLOPPY DISCS
MBA/Kujur/SSD
 Flexible plastic disk inside a diskette cover
 Disc divided into concentric circles called tracks
Tracks are divided into sectors
3.5 Inch Disc

8. Hard Disc
 Use thicker, metallic platters for storage
 Cylindrical storage mechanism
 Large in capacity
 Sensitive instrument – Read/ Write Head
MBA/Kujur/SSD

9. Internal Hard Disk
MBA/Kujur/SSD
•Located inside
system unit/ CPU
cabinet
•Known as a fixed
disk
•Designated as the
C drive with partition
as C:, D:, E:
•Advantage:
•High access
speedSolid State Drive

10. EXTERNAL HARD DISK
 Removable hard disks
 Used to complement internal hard
disk
 Capacities of over 500 GB – 1 TB
MBA/Kujur/SSD

11. HARD DISK PACKS
 Removable storage
 Massive storage capacity
 Common in mainframes
 Used in Banks and bigger
organizations.
MBA/Kujur/SSD

12. Optical Disks
 Compact
 Permanent storage
 Optical disk use reflected light.
 The 1s and 0s are represented by pits & non-
pits.
 Two common types
 CD ( 650 MB to 1GB)
 DVD ( 4.7 GB to 17 GB)
 BRD (25 GB to 50 GB)
MBA/Kujur/SSD

13. Compact Disc
 Optical format
 From 650 MB to 1 GB capacity
 Types
 Read only: CD-ROM
 Write once: CD-R
 Rewriteable: CD-RW
 Picture CDs and Photo CDs
MBA/Kujur/SSD

14.  Digital Versatile Disk or Digital Video Disk
(DVD)
 Similar to CDs, but can store more data
 Types
 Read only
 Write once
 Rewritable
MBA/Kujur/SSD
Digital Versatile Disk

15. Solid State Storage
 Solid-state storage using integrated
circuits
 Variable storage in terra bytes (TB)
 Also called flash drives
MBA/Kujur/SSD