1. Created by S Cox

2. Objectives  Explain the basic differences between Macintosh and Windows computers  Describe what devices are used for entering information into computer systems  Discuss different kinds of input and output devices for multimedia  Compare different kinds of storage devices and discuss their advantages and disadvantages  Describe the computer parts that process data  Learn how computers are connected locally and around the world

3. Learning About Computers  PCs are computers that can be: Used by individuals at home, work, or school Desktop models or portable laptop models Connected to a server in a network  One of the principal differences among computers is the operating system. Operating systems enable computers to run software and perform basic tasks. Most personal computers use Windows or Macintosh (MacOS) operating systems. Windows and MacOS operating systems are not compatible.

4. Learning About Computers  Difference between desktop and laptop computers: Desktop computers are meant to be left in one location and laptops are portable  Personal digital assistants – computers that are small enough to hold in the palm of your hand Today’s PDAs are just about as smart as a desktop or laptop computer

5. Learning About Computers  A server is a computer that manages files and other resources for a network Some are no bigger than a PC, others are larger and more powerful

6. Input Devices  Input is any information you enter into a computer Keyboard – used to enter text Mouse - used to select options by pointing and clicking items on the display screen Keypads – used by touching the characters with a stylus rather than typing

7. Input Devices  Cursor – symbol on the screen that points to specific information  Trackball – a popular variation on the mouse…instead of moving the mouse you move a ball that is set in a stationary holder. Advantage – puts less strain on the arms and uses less desk surface  Touchpad – a flat, built-in pad…press and move your finger on the touchpad to move the cursor

8. Input Devices  Sound input devices Microphones Digital recorders Synthesizers (device for translating musical notes into a digital format for computer input and processing) and musical keyboards  Digital Cameras Digital Still Cameras - pictures Digital Camcorders – record video and sound Webcams – digital video camera connected to the Web

9. Input Devices  Graphics tablets – also called digitizing tablet or digitizer; used to create sketches and drawings in digital format  Scanners – used to convert any printed picture or document to a digital file to upload to a computer Optical character recognition (OCR) – software used to convert scanned text from a paper document or a graphic file into a format that can be edited on a computer  Joysticks – used to send instructions to the computer through a directional lever and one or more control buttons typically used for games

10. Output and Display Devices  Output – Any information that a computer produces  Monitors – display screen Cathode ray tube (CRT) – resembles a TV; an electron beam continuously scans the back of the screen to create images by lighting up phosphor Liquid-crystal display (LCD) – works like a calculator display; applies voltage to liquid crystals which are sandwiched between to magnetic, to light them up; represent color by varying the amount of light that shines through

11. Output and Display Devices  Monitors depend on a graphics card (circuit board for processing and displaying graphics)  Touch Screen – output device, a display, and an input device; ATMs and PDAs use them; used when peripherals (device that is used with a computer but not essential) are inconvenient

12. Output and Display Devices  Plasma Displays – flat-panel; creates images by passing electrical impulses through a neon/xenon gas mixture sandwiched between two sealed glass plates with electrodes on their surface  LEDs – screens that light up when electricity passes through them like PDAs or cell phones  Projectors

13. Output and Display Devices  Printers Ink-jet – spray ink at the paper through tiny nozzles Laser – uses a laser beam and magnetism to transfer fine powder called toner to the paper; similar to a copier LCD and LED – use magnetism and toner, but instead of beams they use liquid crystals and light-emitting diodes  Speakers – computer needs audio card

14. Digital Storage Devices  Hard drives – built in for storing software and information Stores information magnetically Has an arm with a sensor on the end that reads and writes data as it spins

15. Digital Storage Devices  Removable storage CDs – disc used to store and read digital material CD-ROM – can only read data but cannot write to the disc DVDs – optical disks Floppy disks – flexible magnetic disk…becoming obsolete Zip disks – developed by Iomega Corporation Memory cards – small removable digital input modules; used by cameras and audio recorders USB memory drives – also called travel drives, jump drives, memory sticks, or thumb drives

16. Processing Components  Processing includes all the calculations and other operating a computer performs on your input to turn it into output.  Processing takes place on microprocessors, or chips (usually smaller than a fingernail, contains millions of electronic components)

17. Processing Components  Central Processing Unit – controls the computer’s logic and its ability to carry out instructions; used by almost all digital devices (alarm clocks, digital cameras, and CD players) Vary in processing speed; measured in megahertz (MHz) or gigahertz (GHz)…the faster the speed the faster your programs will run Part of the motherboard (main circuit board)  Memory Random Access Memory (RAM) – where the computer stores data while you are working on it ○ Measured in bytes

18. Elements of Communication  In order to exchange files and share resources, computers: Require special input and output devices Must be part of a network, such as: ○ The Internet ○ Local area network (LAN) – connect computers in one location ○ Wide area network (WAN)– connects computers across a wide geographical area

20. Elements of Communication  Types of connections Dial-up connection – a computer uses a modem and a standard telephone line…obsolete Broadband connection – uses dedicated telephone lines or cable television equipment …constant connection ○ Some use DSL (digital subscriber lines) – high capacity telephone lines; the computer must be within a few miles of a telephone company transmitter ○ No DSL – can use cable television or satellite television companies

21. Elements of Communication  Devices for Communications Modems and Broadband Connections – cable modem Modems and Wireless Connections – some modems are wireless and use cellular telephone technology Network cards – to connect to a network a PC needs a network interface card (NIC) Routers – used to connect two or more LANs