1. Business Studies Stage I Computer ApplicationsSlide 1 Output Devices Output Devices are all part of the Hardware of a computer system Output Devices are about seeing the results of your work!

2. Business Studies Stage I Computer ApplicationsSlide 2 Some Output Devices Video Monitor Sound Controlling Other Machines Paper

3. Business Studies Stage I Computer ApplicationsSlide 3 Types of Output Soft Copy Hard Copy Communications Channel

4. Business Studies Stage I Computer ApplicationsSlide 4 Screen Output – Soft Copy Video Monitor –Also called Video Display Terminal (VDT) –Image exists in video memory—VRAM –Monitor size is measured diagonally across the screen

5. Business Studies Stage I Computer ApplicationsSlide 5 Images are made up of dots called pixels for picture elements The number of pixels determines the clarity of the picture on the screen More pixels = higher resolution = clearer picture Pixels

6. Business Studies Stage I Computer ApplicationsSlide 6 Color Depth (Bit Depth) This means the amount of information stored in each pixel about what is being shown on the monitor –Monochrome (1 bit of information per pixel) This can only be black or white –Gray-scale (8 bits of information per pixel) This can show more shades of grey –True color (24 or 32 bits of information per pixel) This can realistically reproduce a photograph on the screen that looks very close to the original

7. Business Studies Stage I Computer ApplicationsSlide 7 Examples of Color Depth 1-bit depth 4-bit depth 8-bit depth16-bit depth The greater the color depth the more colours that can be represented on the screen

8. Business Studies Stage I Computer ApplicationsSlide 8 CRT (cathode ray tube) LCD (liquid crystal display) Classes of Monitors

9. Business Studies Stage I Computer ApplicationsSlide 9 A CRT is a television-style monitor Its features include: –Clear image –Quick response time –Low cost –Very popular CRT (Cathode Ray Tube)

10. Business Studies Stage I Computer ApplicationsSlide 10 Features of CRT Displays Display text and graphics Monitors differ in resolution Standards –SVGA – 1024 x 768, 1208 x 1024 and 1600 x 1200 –XGA – has same resolutions but supports more colours Screen sizes vary from 15” to 21”

11. Business Studies Stage I Computer ApplicationsSlide 11 LCDs comprise flat-panel monitors Found on watches, calculators, digital cameras and notebook computers –Lighter weight –Crisp,clear images –Extra viewing area for same size –More expensive to buy –Consume less power LCD (Liquid Crystal Display)

12. Business Studies Stage I Computer ApplicationsSlide 12 Paper Output – Hard Copy A printer is a device that produces output on paper Most printers today can produce both text and graphics Two types of printers: –Impact printers –Non-impact printers

13. Business Studies Stage I Computer ApplicationsSlide 13 Impact Printers There is some physical contact with the paper to produce the image ie physically striking the paper Types –Line printers –Dot matrix printers

14. Business Studies Stage I Computer ApplicationsSlide 14 Line printers –Used by mainframes for jobs that need a large volume of printing –Limited characters available –Print an entire line at a time –Cheap to run –Not high quality Line Printer

15. Business Studies Stage I Computer ApplicationsSlide 15 Dot Matrix Printer Have a printhead made up of columns of pins –The pins form characters and images as patterns of dots produced when the pins strike the paper –Reasonable quality text and graphics –Inexpensive to buy and run –Noisy

16. Business Studies Stage I Computer ApplicationsSlide 16 Non-Impact Printers Laser Printers Ink-jet printers Bubble-jet printers

17. Business Studies Stage I Computer ApplicationsSlide 17 Laser Printers Laser printers –Image transferred to paper with a laser beam Faster and more expensive than dot-matrix High-resolution output Expensive to buy Quite expensive to run

18. Business Studies Stage I Computer ApplicationsSlide 18 Ink-Jet Printers Ink-jet –Dots of ink are sprayed onto the paper to form the image –Reasonably high quality –Available in colour or B/W –Speed measured in pages per minute –Reasonably priced –Expensive to run

19. Business Studies Stage I Computer ApplicationsSlide 19 Plotters Used by graphic designers/architects –Image transferred to paper with ink pens –Very high resolution –Excellent for scientific and engineering applications

20. Business Studies Stage I Computer ApplicationsSlide 20 Printing Terms Dots per inch (dpi) Pages per minute (ppm) Characters per second (cps) Laser printers – 50 ppm Ink-jet printers – 12 ppm

21. Business Studies Stage I Computer ApplicationsSlide 21 Output You Can Hear Synthesizers can be used to generate music and sounds Many computers have synthesizers Sound cards have built-in synthesizers

22. Business Studies Stage I Computer ApplicationsSlide 22 By turning bit information into movements (robots) or measurements (sensors), machines can control other machines: –Automated factory equipment –Telephone switchboards –Robot arms –Spacecraft Machines Controlling Other Machines

23. Business Studies Stage I Computer ApplicationsSlide 23 Output to a Network – Computer to Computer Needs a Communications channel The Internet and WWW Needs a modem to convert data for transmission across network