This power point presentation summarizes common hardware components used in information and communication technology systems. It describes input devices like keyboards, mice, scanners and touch screens. It also outlines various output devices such as monitors, printers, and data projectors. Finally, it discusses storage hardware including hard drives, solid state drives, CDs, DVDs, and USB flash drives. The presentation provides brief descriptions of each type of hardware component and notes their key features and uses.

1. PAAVAI COLLEGE OF EDUCATION
Paavai Nagar, Nh-7,pachal, Namakkal - 637018
POWER POINT PRESENTATION
2011-2012

2. PAAVAI COLLEGE OF EDUCATION
Paavai Nagar, Nh-7,pachal, Namakkal - 637018
POWER POINT PRESENTATION
NAME : S.MANIKANDAN
OPTIONAL : COMPUTER SCIENCE AND MATHS
ROLL NO : 038

3. HARDWARE

4. Unofficial ICT Hardware Categories
• Input
• Output
• Processing
• Storage
• Communication

5. Input Devices
• Let users enter data into an information system.
• Keyboard, keypad
• Mouse, touchpad
• Bar code reader
• Touch screen
• Data tablet
• Scanner, camera
• Voice recognition

6. Input Devices
• Keyboard, keypad
– QWERTY layout. Designed to be as inefficient as
possible to stop fast typists jamming the early
typewriters
– Dvorak – more efficient key layout puts most
commonly used keys on the home row. Rare!

7. Input Devices
• Mouse, trackball
– Designed for GUI OS
– Ball mouse superseded by optical
– RSI concerns
– Trackball = stationary upside-down mouse
• Touchpad
– When mice are impractical
– On laptops

8. Input Devices
• Bar code reader
– Reads bar codes – converts them to numbers
– Common in supermarkets, libraries, parts
warehouses etc
– Much faster and more accurate than hand-typing
product codes

9. Input Devices
• Touch screen
– Touch sensitive
– Tablet computers
– iPhone
– Railway ticket machines
– Information kiosks
– Bank ATMs
– Easy for public to use
– Can mimic any sort of
interface: buttons are only
images

10. Input Devices
• Data tablet
– Far better than a mouse for art
– Works like a pen
– Pressure-sensitive

11. Input Devices
• Scanner, digital camera
– Digitises analogue documents or pictures
– Scans page like a photocopier
– Use OCR (Optical Character Recognition) to interpret and
digitise printed text
– Resolution determines how detailed the resulting digital
image is.
• 1200 dpi resolution = 1200
dots per inch (2.54cm)

12. Output devices 1
Display the results of processing.
• Monitor
– CRT
– LCD, TFT
– Plasma
– Data projector

13. CRT monitor
• Now extinct!

14. LCD monitors
• LCD = Liquid Crystal Display
• Thin, saves desk space
• Lighter than CRT
• Less power consumption than CRT
• Getting cheaper
• Refresh rates getting better
• Blacks often just grey
• Colour richness not as good as CRT

15. Data Projector
• Very portable
• Very large display
• Struggles in brightly lit rooms
• Colours are often dull
• Excellent for group presentations
• Lamps fail with age

16. Output devices 2
• Printer
– Laser
– Inkjet
– Thermal
– Dot matrix, Impact
• Speakers
• Indicators, LEDs

17. Inkjet Printers
• Cheap to buy, very expensive to replace ink
• Line-by-line printing

18. Dot matrix printers
• The only printer type that strikes the paper…
• Only they can produce duplicates with
pressure-sensitive paper
• E.g. supermarket receipts - two or three
copies (white customer copy, yellow shop
copy) in only one print operation

19. Storage hardware
Stores & retrieves data and software.
• Hard disk
• Solid state disk
• Flash RAM, RAM, ROM
• CD, DVD
• Tape, floppy disk

20. Hard Disk Drive
• ‘HDD’
• Magnetic storage
• Multiple aluminium platters stacked on a
spindle
• Average HDD platters 3½” (inches)
• Laptop platters 2½”
• MP3 players 1”

21. USB Flash Drives
• NAND memory
• Normal RAM (Random Access Memory)
loses its memory contents when power is
turned off
• Normal ROM (Read Only Memory) has its
contents burnt at the factory and they
cannot be changed later

22. USB Flash drives
• Small, light, rugged (sealed, no moving parts)
• Cheap ones can be rather slow
• Typical capacity from 64M to 64G.
• Easily lost or left behind - possible security
issues
• Some USB Flash drives can be encrypted

23. CD, DVD
• Aluminium layer embedded in a 5¼”
polycarbonate plastic disc
• Laser burns data digitally as pits
• Data also read by laser beam
• Continuous, spiral data
track extends from innermost
to the outermost track, covering
the entire disc surface

24. CD, DVD
• Sensitive to scratches, heat
• Immune to magnetic effects
• Not “perpetual storage” as originally believed.
– Disks degrade over time, become unreadable
– Gold disks seem to last longer
The laser lens in
a CD drive

25. THANK YOU
BY
S.MANIKANDAN