Hardware and Multimedia Chapter 4

1. Created by S Cox Hardware and MultimediaChapter 4

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