2. Chapter 5

3. Input  Users submit input data Output  Users get processed information

4.  Data from the user to the computer  Converts raw data into electronic form

5.  Traditional ◦ Looks like typewriter with extra keys  Non-traditional ◦ Fast food restaurants ◦ Each key represents a food item rather than a character

6. Function Keys  Give commands  Software specific Main Keyboard  Typewriter keys  Special command keys

7. Numeric Keys Num Lock – toggle On – n umeric data & math symbols Off – cursor movement Cursor Movement Keys

8. Enter Esc Alt Ctrl Caps Lock Shortcut Windows Shift

9.  Position a pointer / cursor on the screen  Controls drawing instruments in graphics applications  Communicate commands to a program

10.  Types ◦ Mechanical ◦ Optical ◦ Wireless  Features ◦ Palm-sized ◦ 1 or 2 buttons ◦ Wheel

11. Trackball Upside-down mouse Ball on top Roll ball with hand Laptop computers Touchpad Pressure-sensitive pad Cursor moves as you slide your finger Laptop computers

12. Pointing stick Pressure-sensitive post Mounted between G and H keys on keyboard Apply pressure in a direction to move cursor Joystick Short lever Handgrip Distance and speed of movement control pointer position

13.  Digitizing tablet  Rectangular board  Invisible grid of electronic dots  Write with stylus or puck  Sends locations of electronic dots as stylus moves over them  Creates precise drawings  Architects and engineers

14.  Human points to a selection on the screen  Types ◦ Edges emit horizontal and vertical beams of light that crisscross the screen ◦ Senses finger pressure ◦ Light pen for pointing

15.  Kiosks ◦ Self-help stations ◦ Easy to use ◦ Where found  Malls  Disney World  Government offices

16.  Small hand-held devices  Electronic pen (stylus) ◦ Pointer ◦ Handwritten input  Personal Digital Assistants (PDA)

17.  Special equipment to collect data at the source  Sent directly to a computer  Avoids need to key data  Related input areas ◦ Magnetic-Ink Character Recognition ◦ Scanners ◦ Optical recognition devices ◦ Voice

18.  Read characters made of magnetic particles  Numbers on the bottom of checks  MICR inscriber – adds characters to check that show amount cashed

19.  Optical recognition  Light beam scans input data  Most common type of source input  Document imaging – converts paper documents to electronic form  Converts snapshots into images  Converts scanned picture into characters – OCR Exact computer-produced replica of original Exact computer-produced replica of original

20.  Flatbed ◦ One sheet at a time ◦ Scans bound documents  Sheetfeed ◦ Motorized rollers ◦ Sheet moves across scanning head ◦ Small, convenient size ◦ Less versatile than flatbed ◦ Prone to errors

21.  Handheld ◦ Least expensive ◦ Least accurate ◦ Portable ◦ User must move the scanner in a straight line at a fixed rate ◦ Wide document causes problems

22.  Photoelectric device  Reads bar codes  Inexpensive  Reliable  Where Used? ◦ Supermarket – UPC ◦ Federal Express

23.  Speech Recognition  Speech recognition devices ◦ Input via a microphone ◦ Voice converted to binary code  Problems ◦ Speaker-dependent ◦ Voice training

24.  Changing radio frequencies in airplane cockpits  Placing a call on a car phone  Requesting stock-market quotations over the phone  Command from physically disabled users

25.  Information for the user  Types ◦ Screen – soft copy ◦ Printer – hard copy ◦ Voice ◦ Sound ◦ Graphics

26.  Data that is entered appears on the screen  Screen is part of the monitor

27. Cathode Ray Tube (CRT) Flat panel display Liquid Crystal Display (LCD)

28. Raster scanning  Sweeping electron beams across the back of the screen  Phosphorous coating on back  Glows when hit by a beam of electrons  Phosphorous loses glow and image fades and flickers  Image must be continually refreshed

29. Refresh rate / scan rate  Number of times electron beams refreshes the screen  80-100 times per second adequate for clear screen image  Process also used for television

30. Color vs. Monochrome  Color ◦ Typical monitor sold today  Monochrome ◦ Green or amber on a contrasting background ◦ Less expensive than color

31. Size  Measured diagonally  Typical sizes ◦ Office user: 15-17 inch ◦ High-powered graphics user: 19 inch ◦ High-end monitors: 21 inches and up  Larger size ◦ More expensive ◦ More space on desktop ◦ Reduces eye strain

32.  Liquid Crystal Display (LCD)  Primarily on laptops  Moving to desktop  Skinny (depth) regardless of size

33.  Crisp, brilliant images  Easy on eyes  No flicker  Full dimension is useable  More expensive that CRT monitors

34.  Active Matrix ◦ Thin-film transistor technology (TFT) ◦ Transistors for each pixel ◦ Brighter image ◦ Viewable from an angle  Passive Matrix ◦ Fewer transistors ◦ Cheaper ◦ Less power

35.  Produces information on paper  Orientation ◦ Portrait ◦ Landscape  Methods of printing ◦ Impact ◦ Nonimpact

36. Line printer One line at a time High volume Low quality Dot-matrix printer One character at a time

37.  Transfers images to paper using a light beam  Prints one page at a time  600-1200 dpi – High quality  Speed ◦ Personal laser printers: 8-10 ppm ◦ Network laser printers: 35-50 ppm ◦ High-volume laser printers: up to 1000 ppm  Black and white / color

38.  Spray ink at paper  Black and white / color  Low cost  Need high quality paper  Slower than laser

39. Creates multimedia output Multiple sight and sound effects Speakers Sound card

40.  Enables machines to talk to people  Types ◦ Voice synthesizers ◦ Voice output devices ◦ Audio-response units  Convert data in storage to vocalized sounds  Synthesis by analysis – human sounds are stored and reproduced as needed  Synthesis by rule – creates artificial speech

41. Uses  Automobiles  Telephone surveys  Catalog order is ready  Your payment is late reminder

42.  Business  Education  Science  Sports  Computer art  Entertainment

43.  Types ◦ Maps ◦ Charts  Help ◦ Compare data ◦ Spot trends ◦ Make decisions quickly  Attention-getting  Updated instantaneously  Rendered quickly

44.  Animated graphics  Prepared one frame at a time  Examples ◦ Cartoons ◦ Commercials without humans ◦ Television network’s logo ◦ Arcade games