Computer Basics Lesson 3 (Cont.)

1. Keyboard Review & Pointing Devices Computer BasicsLesson 3 (Cont.)

2. Num Lock • When Num Lock is on, the Minus key performs subtraction on the numbers entered. • When Num Lock is off, the Minus key will type a hyphen like this -.

3. Important Keys • On the number/symbol row, the top of the key is the symbol. To key the top characters a typist would have to press the shift key. • The page down key is a navigation key which will drop the displayed area down the page one screen’s worth.

4. Important Keys • The page up key will move the cursor up the displayed area one screen’s worth. • The space bar allows blank spaces in text. • The Tab key is used in documents to move the cursor over to the right to a pre-set point.

5. Pointing Devices • A ball or laser underneath rolls as the mouse moves across the mouse pad. • The cursor on the screen follows the motion of the mouse. • Advantage: Moves cursor around the screen faster than using keystrokes. • Disadvantages: • Requires moving hand from keyboard to mouse and back. • Repeated motion can lead to carpal tunnel syndrome.

6. Pointing Devices • Other pointing devices include: • Trackball • Glide pad • Game devices • Pen input • Touch screen • Digitizers • Graphic tablets

7. Trackball • Instead of moving the whole mouse around, the user rolls the trackball only, which is on the top or side. • Advantages: • Does not need as much desk space as a mouse. • Is not as tiring since less motion is needed. • Disadvantages: • Requires fine control of the ball with just one finger or thumb. • Repeated motions of the same muscles is tiring and can cause carpal tunnel syndrome.

8. Glidepad • Uses a touch sensitive pad for controlling cursor. • The user slides finger across the pad and the cursor follows the finger movement. • For clicking there are buttons, or you can tap on the pad with a finger.

9. Glidepad • Advantages: • Does not need as much desk space as a mouse. • Can readily be built into the keyboard. • Has finer resolution. • Can use either buttons or taps of the pad for clicking. • Disadvantages: • The hand tires faster than with a mouse since there is no support. • Some people don't find the motion as natural as a mouse.

10. Game Devices • Cursor motion controlled by vertical stick (joystick) or arrow buttons (gamepad). • Advantages: • A joystick gives a more natural-feeling control for motion in games, especially those where you are flying a plane or spaceship. • Both have more buttons for special functions than a mouse and can combine buttons for even more actions. • Disadvantages: • More expensive • Bulky • Better ones require an additional peripheral card for best performance

11. Pen Input • Pen Input is used for: • Data Input - by writing. PDA recognizes your handwriting. • Pointing Device - Functions like a mouse in moving a cursor around the screen and clicking by tapping the screen. • Command Gestures - You can issue commands by moving pen in patterns. So a certain kind of swirl would mean to save the file and a different kind of swirl could mean to open a new file.

12. Pen Input • Advantages: • Can use handwriting instead of typing • Can use gestures instead of typing commands • Small size • Disadvantages: • Must train device to recognize handwriting. • Must learn gestures or train device to recognize the ones you create • Can lose the pen which is not usually attached to the device

13. Touchscreen • Make selection by just touching the screen. • Advantage: • It's natural to do - reach out and touch something. • Disadvantages: • It's tiring if many choices must be made. • It takes a lot of screen space for each choice since fingers are bigger than cursors.

14. Digitizers and Graphics Tablets • Converts drawings, photos, etc. to digital signal. • Advantages: • Don't have to redraw graphics already created. • Most find it easier to draw with a stylus than with a mouse. • Disadvantage: • Expensive