Lesson 2 Essential Computer Concepts

Transcription

1 Essential Computer Concepts Computer Literacy BASICS: A Comprehensive Guide to IC 3, 3 rd Edition 1

2 Objectives Identify and describe standard and specialized input devices. Identify and describe standard and specialized output devices. Identify and describe how input and output devices are connected to the computer. Consider computer performance factors. 2

3 Introduction Input, which is data or instructions, must be entered into the computer and then stored on a secondary storage media device. To turn the data into information, the CPU processes the data. After data is processed, it is presented to the user through an output device. 3

4 Standard Input Devices Input devices enable you to enter data and commands into the computer. Keyboard: Most commonly used input device. Besides a traditional keyboard, popular types include: Ergonomic Cordless or wireless Specialized Security Foldable or flexible Laser virtual keyboard 4

5 Standard Input Devices (continued) Pointing Devices: An input device that allows you to position the pointer on the screen. Mouse: Most commonly used pointing device. Types include: 5 Mechanical Optomechanical Optical Wireless Optical mouse

6 Standard Input Devices (continued) Trackball: A pointing device that works like a mouse turned upside down; the ball is on top, operated by your thumb and fingers. Touchpad: Common feature on laptops; a specialized surface that converts the motion and position of your fingers to a position on the screen. 6

7 Standard Input Devices (continued) Pointing Stick: A pressure-sensitive device located on the keyboard of many notebook computers and moved with the forefinger. Audio Input: The process of inputting sound into the computer, including speech, sound effects, and music. 7

8 Specialized Input Devices Digital Cameras: Pictures are stored digitally and then transferred to the computer s memory. Game Controllers: Joysticks and wheels are most often used for games. Joystick 8

9 Specialized Input Devices (continued) 9 Scanners/Bar Code Readers: Can change images into codes for input into the computer. Various types include: Image scanners Bar code scanners Magnetic scanners Wireless scanners Optical character recognition (OCR) and optical mark recognition (OMR) Optical scanner

10 Specialized Input Devices (continued) 10 Touch Display Screen: Special screen with pictures or shapes; you use your fingers to make selections. Stylus: Pen-like writing instruments to input information to a PDA or other mobile device.

11 Specialized Input Devices (continued) Security Devices: Biometric devices consist of a reader or scanning device and software that converts the scanned information into a digital format. The way biometric technology works: Enrollment: User establishes baseline measurement Submission: User presents proof of identity Verification: System compares samples 11

12 Standard Output Devices Output is data that has been processed into a useful format. Output devices display information. Monitors: Display device for a desktop computer. Varieties include CRT, LCD, and gas plasma. CRT monitor 12

13 Standard Output Devices (continued) Printers: Used to produce a paper or hard copy of the processing result. Consider speed, print quality, and price when choosing. Laser Printers: Produces high-quality output using the same technology as copier machines. 13

14 Standard Output Devices (continued) Inkjet Printers: Uses a nonimpact process to provide goodquality color printing for less expense than a laser printer. Speakers: Generate sound such as music. Individuals can use headsets or earphones to hear privately. 14

15 Specialized Output Devices 15 Projectors: Mostly used for presentations. Fax machines and fax modems: Transmit and receive documents through phone lines or computer. Multifunction printer: Combines various output options such as printing, scanning, and copying. Control devices/robots: Robotics is the study, design, and use of robot systems for manufacturing.

16 Specialized Output Devices (continued) Output Devices for the Physically Challenged: Various special devices are available: Screen magnifiers: Enlarge information on the computer screen. Screen readers: Use speech synthesizers to read content for people who are blind or visually impaired. Voice synthesizers: A voice changes written computer text into synthetic speech. 16

17 Connecting Input and Output Devices to the Computer 17 Ports and Connectors: A port, or jack, is an interface to which a peripheral device attaches to or communicates with the system unit. Besides traditional, FireWire, and USB ports, specialpurpose ports include SCSI, IrDA (infrared), and Bluetooth.

18 Connecting Input and Output Devices to the Computer (continued) Hardware Installation: For most hardware devices to work, they need a set of instructions that communicates with the computer s operating system, called a driver. If the operating system already contains the driver, it performs an automatic plug-andplay installation for newly connected devices. 18

19 Computer Performance Factors A variety of factors affect a computer s performance: Microprocessor: The higher the generation, the faster and better the processing speed. Random access memory (RAM): Helps increase the processing cycle and enhance performance. Hard disk: Bigger and faster process data faster. Video: Can enhance or slow down performance. 19

20 Summary In this lesson, you learned: Input devices enable you to input data and commands into the computer. The most common input devices are the keyboard and mouse. Other types of input devices include the trackball, joystick, wheel, pointing stick, graphics tablet, touch display screen, stylus, voice recognition devices, touchpad, scanner, digital camera, video input, and biometric input. 20

21 Summary (continued) Monitors and printers are examples of output devices. Monitors produce soft copy. Printers are used to produce a paper or hard copy of the processed result. Criteria for selecting a printer include speed, print quality, and cost. 21

22 Summary (continued) Input and output devices must be connected to the computer. Some input and output devices communicate with the computer through a physical connection. Wireless devices communicate with the computer through infrared or radio waves. Peripheral devices are connected to the computer through serial, parallel, and Universal Serial Bus (USB) ports. USB is a newer standard expected to replace serial and parallel ports. 22

23 Summary (continued) FireWire is a type of external bus that can connect up to 63 external devices. SCSI, IrDA, and Bluetooth are specialpurpose ports. A computer s performance is affected by the speed of the processor (hertz), the amount of RAM, hard disk size and speed, capability of monitor, and disk organization. 23