DATA STORAGE DEVICES
Name: Ravi Vemuri
Introduction
• Data Storage Devices are used for reading and
writing data in a reliable way
• It stores data in the form of virtual mater using any
format of energy for storage
• It is considered to be a permanent storage which
requires electrical power for any operations.
• Also it has a volatile memory
Magnetic Storage Devices
 Stores data in a magnetized medium using
magnetization
 It has a fast access to data and store large amounts
of data. Access speeds of 1Mbps.
 Examples are Hard drive and Floppy Disk.
CWID:11663389
Hard Drive
CD(Compact Disc)
oStores and retrieves digital information. It is a non
volatile storage which has a capacity around 8GB
oAvailable as external hard drives connected by USB
oIt is portable and is not very expensive
 This is a digital Optical Storage and is portable
 Made of molded polymer used for storing and
retrieving data. Capacity is around 700MB
 Different types of CD like CD-R, CD-RW
DVD(Digital Video Disc)
 Stores different digital data used to access
different data files
 Capacity is around 5GB-18GB
 It is pretty much larger than a CD
 Different DVD like DVD-R,
DVD-RW etc.
Methods
There are 3 data storage methods available
 Portable : Replaces the data
 Semi-Portable : Requires mechanical disassembly
tools. Hard disk and non volatile
 Volatile : Loses data when power gets disconnected
Optical Storage Devices
Primary Storage Device
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 These are actually the fastest data storage devices.
 They consists of RAM and Cache
 They are primary storage because they have a
direct access to the CPU
Floppy Disk
They consists of a thin and flexible magnetic storage. It
is contained in plastic rectangular type which eliminates
dust particles.
It has a capacity of only 256MB.
Utilizes optically readable medium
Laser beam focused on a single disk stores the data
It is Non Volatile in nature and uses low power
They are durable
Examples are Blu-Ray disk, CD, DVD, CD-ROM
Cloud Storage
 Uses online storage media which requires
Internet for storing data
 Verified account holders can access any data
 Primary edge is that it is helpful in recovery. It
can also be accessible using the internet
Future Scope
o Storage medium of 25-30GB of optical storage
that consists of a single layer
o There is a development for 500GB holographic
optical storage up to 4 layers
References
1) www.igcseict.info/theory/3/mag
2) https://en.wikipedia.org/wiki/Data_storage_
device
3) https://en.wikipedia.org/wiki/Optical_storage