1. Information Processing Lecture 2 A Peripherals

2. Objectives For Week 2 After studying this week’s 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 = 2 10

9. Secondary Storage Criteria: Capability –Size –flexibility Integrity of Data Cost Speed

10. Storage Devices 1 Floppy 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 2 Hard Drives Stack of magnetically coated rigid disks (platters) Hermetically sealed unit Disks are subdivided into tracks, sectors etc.

12. Storage Devices 3 Optical 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