El documento presenta la importancia del almacenamiento secundario, destacando sus ventajas como la no volatilidad, rapidez y bajo costo. Se describen diferentes tipos de dispositivos de almacenamiento, incluyendo discos duros, cintas magnéticas y discos ópticos, junto con sus capacidades y características. También se menciona la evolución de la tecnología de almacenamiento, enfatizando el uso de medios como los discos CD y DVD.

1. PRESENTED BY:
Sabin Kafle

2. Why secondary storage?

3. Non-Volatile
Faster
Simple, Portable, Easy
Memory Unlimited
Popularity
Cheaper than Primary Memory
Points to Remember

4. Storage Devices
 Disk types
• Floppy disks
• Hard disks
• Magnetic Tape
• Zip disks
• Flash drive
• Optical disks ( CD-ROM, CD, DVD, RW)

5. Magnetic Storage Devices
Floppy Disk
 low capacity only 1.44 Mb
 Zip as ‘Super floppies’ 100 Mb
 Read-write
 Small, light, portable
 Outdated

6. Magnetic Sorage Device
Hard Disk
 Non-Volatile
 Faster than floppy
 Higher capacity terms of GB.
 Non-removable, Removable, most common.
 R-W drive
 1st
introduced in IBM PC
 Coated with magnetic material
 Expensive one

7. Magnetic Storage Device
Magnetic tape
Ribbon of plastic material
Magnetic recording
Analogue data
RW and Durable
Capacity depends upon length and size
Not suitable for data files

8. Storage Device
Optical disks
CD-ROM
 Non-Volatile
 Digital optical device
 laser technology, extremely fast
 Typical capacity of 700 Mb
 Store any type of data
 Being replaced
 Diameter of 120mm
 Thickness of 1.2mm
 Low quality playback than DVDs

9. Storage Devices
Compact Disc-Recordable
Write Once Read Many
Made of polycarbonate
Retains a high level of compatibility
Cheaper form
Read using Laser light
CD-R
Optical disk

10. Optical Storage Device
CD-RW
Rewritable optical disc
Require a more sensitive laser optics
Hardware with RW is required
Re-Written up to 10,000 times

11. Recordable optical disc
Cheaper
Records multi-formats
Capacity of 4.7GB
 Non-Volatile data storage
Optical Storage Device
DVD-R

12. Optical Storage Device
DVD-RW
Rewritable optical disk
Typically 4.7GB
Hardware capability required
Widely used
Diameter of 8 cm

13. Electronic Storage Device
Flash memory
Opto-Magnetic storage
EEPROM based technology
Data transfer
Portable, Easy, Simple
Higher speed
Multiple purpose