system storage

system storage,hard disk,flash drives,hard disk drives,storage devices

3. Presented by
Muhammad Jawad Zafar (group leader)
Aiza
Ahsan
Laraib
Muqaddas
Saba
Minhal
Tooba
Mahjamal
Rabia

5. Introduction
Storage holds data instructions and information for future
use.
Types:
There are two types of storage
Primary storage
This stores data during computer operations. For example,
RAM (Static RAM, Dynamic RAM)
ROM (PROM, EPROM, EEPROM)
Processor registers (Programme register, Address register,
Accumulative register, Storage register)
Processor cache

6. Secondary storage
This stores data permanently. For example,
Hard disc,
USB Flash,
Optical Discs,
Memory Cards.

7. Storage Devices
These are hardware components used to store data
instructions and information permanently.
They are non-volatile.
Examples: Hard disc, USB flash, Optical disc, smart
cards, Magnetic strip etc.

8. Capacity: it is the number of bytes (characters) a
storage medium can hold.
Examples:
USB flash drive store upto 4GB.
Hard disc store upto 320GB.
Writing: it is a process of transferring data
instructions and information from memory to storage
medium.
Reading: it is a process of transferring items from
storage medium into memory.

9. Access time: it is the time taken by the storage device
to locate items on storage medium.
Access time of storage device is low as compared to the
access time of memory
Speed of storage device is defined by access time.

10. Hard Disc
Hard disc is a storage devise that contain one or more
inflexible circular platters that use magnetic particles
to store data.
A system unit contain at least one hard disc.
Current PC’s have storage capacity of 160GB to 2TB.

11. Characteristics of Hard disc:
Capacity
Platter
Read/write heads
Cylinders
Sectors and tracks
Revolution per minute
Transfer rate
Access time

12. Longitudinal recording:
In longitudinal recording magnetic particles are
aligned horizontally around the surface of disc.
Perpendicular recording:
in perpendicular recording magnetic particles are
aligned vertically to the disc surface. Which make
storage capacity.
Storage capacity in perpendicular recording is 10 times
greater than longitudinal recording

13. Working of Hard Disc
Step 1: The circuit board controls the movement of the
head actuator and a small motor.
Step 2: A small motor spins the platters while the
computer is running.
Step 3: when software request a disc access the
read/write heads determinate the current or new
location of data.
Step 4: The head actuator positions the read/write
head arms over the correct location on the platters to
read or write data.

15. Types:
Fixed Hard disc:A hard disc that is mounted inside the
system unit.
Portable Hard disc: A hard disc that can be removed from
one computed and can be placed in other computer.
External hard disc: It is separate free standing hard disc
that connects with a cable to USB port on system SU.Its
storage capacity is upto 4TB or more.
Removable Hard disc: It is a hard disc that can be
inserted and removed from a drive. They have storage
capacity upto 1TB or more.

16. Miniature hard disc:
Devicessuchasportablemediaplayersdigital
camerasandsmartphoneshaveminiatureharddisc
whichprovidegreaterstoragecapacity.
Storagerangefrom4GBto250GB

17. Hard disk controller
Itisanelectroniccircuitthatcontrolthetransferof
datainstructionsandinformation.
Itcontrolstheinterfacebetweentheharddiscand
systembus.
Types:
SATA
EIDE
SCSI
SAS

18. SATA (serial advanced technology attachment)
it uses serial signals to transfer data, instructions and
information.
It has thinner, longer, more flexible, and less
susceptible cables than parallel signals.
It can support connection to optical disc driver.
External disc use “e SATA” intereface.

19. EIDE (enhanced integrated drive electronics)
It is hard disc interface.
It uses parallel signals to transfer data instructions and
information.
It support upto 137GB.
It also provide connection for optical disc and tape
drives.

20. SCSI (small computer system interface)
It uses parallel signals to transfer data instructions and
information.
It can support upto 8 or 15 peripheral devises.
Some computer use an adopter card to add a SCSI
interface.
SAS (statical analysis system)
It is newer type of SCSI.
It uses serial signals to transfer data.

21. Advantages of SAS over parallel SCSI
It have thinner longer cables
Reduce interface.
Less expensive
Support many devices at once

22. Flash Memory Storage
It is a type of non-volatile storage.
Data can be erased electronically and rewritten.
Types:
Solid State Drive:
It uses flash memory to store data, intructions and
information.
With available size of 3.5 inches, 2.5 inches and 1.8 inches.
Advantages of SSD:
Access time of SSD are about 0.1 ms.
It is 80 time faster than hard disc.
SSD generate less heat and consume less power than hard
disc.

23. Memory Card:
It is removable flash memory device.
Usually not bigger than 1.5 inches.
Types:
Compact Flash
Secure Digital
Micro SD
Memory Stick
Memory Stick Micro

25. USBFlashDrive:
Itisalsocalledthumbdrive.
ItcanbeplugintotheUSBportofthecomputer.
Storagecapacityrangesfrom512MBto64GB
ExpressCardModule:
Itisremovabledevice.
About75mmlongand34mmwideorLshapedwith
widthof54mmthatfitsinexpresscardslot.
Itiscommonlyusedinnotebookcomputers

27. Cloud Storage
Cloudstorageisaninternetservicethatprovideshard
discstoragetothecomputerusers.
Feearrangementsvary
Forexample:Onecloudstorageserviceprovides25GB
ofstoragefreetoregisteredusers.
Forenterprises,cloudstoragecharges15centsperGB.

29. Variety of Reasons:
To access files on internet
To allow others to access their files on internet.
To view time-critical data and images. For example
doctor can view x-ray images from an other hospital.
To store offsite backups of data.

30. Optical Disc:
Optical disc is a type of optical storage media that
consist of flat, round, portable disc made of metal,
plastic and lacqouer.
Size ranges from4.75 inches in diameter and less than
1/20
th
of an inch thick.
Optical disc storesoftware,data,digital
photos,movies and music.

31. Types of ODD:
CD Drive:
It is a device used by computer to read and write data
from or to a CD.
Types of CD Drive:
1.CD-ROM: Read data from CD
2.CD-R Drive: Read data from CD and can also write to
CD
3.CD-RW Drive: Read, write and rewrite

32. DVD drive:
Sands for digital versatile/video disc.
It is used to store music, videos, games and multimedia.
It is similar to CD in appearance.
Its storage capacity is 7 times greater than CD.
Blue-Ray drive:
It is the name of next generation optical disc format.
It enable us to record upto 25 GB.
It is 6 times the capacity of DVD.
Single layer BD can store upto 25 GB data and double can
store upto 50 GB data.

33. Types:
BD ROM: (Read Only)
For pre-recorded contents.
BD-R: (Recordable)
For PC data storage.
BD-RW: (Re-writable)
For PC data storage.
BD-RE: (Re-writable)
For HDTV recording.

34. Tape
One of the first storage media used with main frame
computer
Tape:
It is magnetically coated with ribbon of plastic capable of
storing large amount of data.
Tape drive:
Tape drive read and write data and information on tape.
Tape cartridge:
It is a small rectangular plastic housing of tape.
Tape Library:
On larger computers tape cartridge are mounted in
separate cabinet called tape library.

35. Magnetic strip cards and smart
cards
Magnetic Stripe Card:
It is a credit card, bank card, entertainment card or other
similar cards. With a strip that contain information
identifying you and the card.
Information stored in the strip include your name, account
number and expiration date.
Smart Cards:
It is smaller in size to the credit card or ATM card.
It stores data on thin microprocessor embedded in the card
Smart card can double as an ID card.

36. Uses of Smart Card :
Storing medical record
Vaccination data
Tracking information
Storing Prepaid amount of money
Authenticating users.

37. Microfilm and Microfiche
They both can store microscopic images of documents
on roll or sheet films
Microfilm is 100 to 215 foot roll of film.
Microfiche is small sheet of film about 4×6 inches.
Uses:
Use in library
Large organizations
Banks
US Army for personal records.

38. Advantages:
They reduce the amount of paper.
They have longest life of any storage media

39. Enterprise Storage
A large business refer as enterprise has thousands of
employs working all over the world.
They use computer network to manage their data
(includes huge volume of information about employs,
customers and suppliers)
They use hardware components for storage.
one or more server has only work of providing storage
to connected users.
Some systems have storage capacity of 185 TB