MAC OS – Unit A

Page: 6-7, 8-9

Examining Input Devices

Examining Output Devices

Examining Input Devices

Before a computer a computer produce useful information, a user must get data into it.

This is done using Input Devices.

Types of Input Devices - Keyboard

One of the most frequently used input devices is the keyboard.

There are two kinds of keyboards: Standard Ergonomic: Ergonomic means that it has been

designed to fit the natural placement of the hands

Ergonomic Keyboard

Standard Keyboard

Types of Input Devices- Mouse

The pointing device that is known as the mouse controls the pointer. That is a small arrow on the screen.

Pointing devices are used to select and move graphical icons on the screen. A mouse has two buttons for clicking commands.

A mouse has a track wheel used for scrolling through the page. Sometimes you have a track wheel that is used to move the

arrow of the device without moving the mouse. Notebook computers have a track pad. That is a touch-

sensitive device that you drag your finger over to control the pointer.

Track ball

Track pad

Types of Input Devices - Scanner

A scanner is an device that transfers the content on a piece of paper into memory.

Microphones are another types of input devices.

Input devices can be connected to the computer either with cables or wirelessly.

Microphone

Scanner

Quick Quiz

Which of the following is a pointing device that allows you to control the pointer by moving the entire device around the desk ? Mouse Trackball Track pad Pointing stick

Answer : Mouse

Types of Output Devices

Output is the result of processing input.

Output devices show you these results.

Types of output devices: monitor, printer, speakers, etc..

Monitor

1. Monitor displays output from the computer.2. Figure A-9 , Page 9 shows two types of monitors:

1. Flat Panel Monitor: a light weight monitor that takes very little space on the desktop. Their images are created used LCD (Liquid Crystal Display)

2. CRT (Cathode Ray Tube): require more space to be placed on the desk

3. Apple’s Mac: combines the LCD monitor with other components into one unit.

CRT

Flat Panel

Apple’s Mac

Quick Quiz

7. What are the three types of monitors?

7. Flat panel monitor8. CRT monitor9. Apple’s Mac

Monitor Display

Monitor screen size is the diagonal measurement from one corner of the screen to the other. Desktop computer range from 15” to 30” Notebook computers range from 12” to 20”

Monitors have graphic display which divides the screen into a matrix of dots called pixels.Resolution is the number of pixels the computer displays.

Monitor Display – Cont. Dot pitch (Dp) measures the distance between

pixels. A smaller dot pitch means a sharper image

To display graphics, a computer must have a graphics card, also called video display adapter or video card.

Printers A printer produces a paper copy, often called

hard copy of the text or graphics processed by the computer.

There are three categories of printers: Laser Printers: They produce high quality output

quickly. A temporary laser image is transferred into paper with a powdery substance called toner.

Inkjet Printers: are usually used at home. They spray ink into the paper and produce good quality output

Dot Matrix Printers: transfer ink into the paper using striking a ribbon with pins. They are used for large papers.

Laser Printer

Dot matrix Printer

Inkjet Printer

Speakers Speakers, are like speakers on sound system,

allow you to hear sounds from the computer.

Speakers can be built in or external peripheral devices that would be attached to the computers.

Quick Quiz In order to display graphics, a computer monitor

needs : Parallel port Network card Graphics card Sound card

Answer: Graphics Card