Information Processing

1
Information Processing

• Lecture 2A
• Peripherals

2
Objectives For Week 2

• After studying this weeks work, you should have
• examined the different types of peripherals that
  can be used to augment a computer system, and
  understood how some of these function.
• collaborated with others, in order to research
  and present a topic, and acquired knowledge about
  how to present information more effectively.
• engaged with some of the social and ethical
  issues related to the use of computers.

3
Peripherals

• These are devices other than the main processor
  board and memory
• Three categories
• Input
• Output
• storage

4
Input Peripherals

• Keyboard
• Mouse
• Touch Screen
• Joysticks
• and?

5
Input Peripherals

• Speech Input Device
• Digital Camera
• Video Camera
• Graphics Tablet
• Pen-Input
• Tracker Balls
• OMR
• and many more

6
Output Peripherals

• VDU
• Plotters
• Printers
• Others?

7
Storage

• Primary Storage
• Internal (RAM/ROM etc.)
• Secondary Storage
• Peripheral devices

8
Data Sizes

• Bit
• Nibble
• Byte ( 8 bits)
• Kilobyte ( 1024 B)
• Megabyte ( 1024K)
• Gigabyte (1024 Mb)
• Terabyte (1024 Gb)
• NB 1024 210

9
Secondary Storage

• Criteria
• Capability
• Size
• flexibility
• Integrity of Data
• Cost
• Speed

10
Storage Devices 1Floppy Disks

• Circular plastic coated with magnetic layer
• 360k to 2.33 Mb
• Once industry standard
• Replaced by CD-ROM
• Formatting
• Double-sided
• Tracks (concentric circles)
• Sectors (sections of tracks)

11
Storage Devices 2Hard Drives

• Stack of magnetically coated rigid disks
  (platters)
• Hermetically sealed unit
• Disks are subdivided into tracks, sectors etc.

12
Storage Devices 3Optical Drives

• CD-ROM , DVD
• Single spiral track
• Divided into sectors
• CD 240 tracks per cm approx.

13
CD Standards

• CD (CD-DA)
• Red Book
• Designed for music
• Allows for text
• 72 mins of hi-fi sound
• CD-ROM
• yellow Book
• Accepted standard
• CD-I
• Green Book
• Interactive
• Own operating system

14
Tape Storage

• Sequential Access Devices
• Reel to reel
• Digital Audio Cartridges
• Able to store Mb, Gb, Tb of data.

15
Discussion

• Offer brief descriptions of how you think the
  following peripherals work
• A Keyboard
• A Mouse
• A Bar-Code Reader
• A Scanner
• A Laser Printer

16
What have we covered?

• Peripherals
• Storage Devices

Further information on how computer hardware
functions can be found at http//howstuffworks.
com