UNIT 1 (1.1) COMPUTER HARDWARE

UNIT 1 (1.1) COMPUTER HARDWARE

1. An input device is any hardware device that sends data to a computer.

   • Examples are keyboards, mouse, scanners, digital camera, joystick.

2. An output device is any device used to send data from a computer to another device or user.

   • Examples are headphones, speakers, graphics card, inkjet printer, monitor, microphone.

3. Advantage of networks

   • Sharing devices such as printers saves money.
     • Site (software) licences are likely to be cheaper than buying several standalone licences.
       • Site (software) licences are likely to be cheaper than buying several standalone licences.
         • Network users can communicate by email and instant messenger.
           • Security is good - users cannot see other users' files unlike on stand-alone machines.
             • Data is easy to backup as all the data is stored on the file server.

4. Disadvantage of networks

   • Purchasing the network cabling and file servers can be expensive.
     • Managing a large network is complicated, requires training and a network manager usually needs to be employed.
       • If the file server breaks down the files on the file server become inaccessible. Email might still work if it is on a separate server. The computers can still be used but are isolated.
         • Viruses can spread to other computers throughout a computer network.
           • There is a danger of hacking, particularly with wide area networks. Security procedures are needed to prevent such abuse, eg a firewall.

5. Keyboard:This is the most common method of inputting data or instruction to a computer.

6. Mouse: A point and click device, the mouse allows the user to communicate with the computer by placing a cursor at a particular point on the screen.

7. scanner: This input device converts a document or photograph into a digital file that a computer can read or display.

8. Sensors: These are physical devices such as thermometers, motion sensors and microphones that send signals to the computer.

9. Microphone: These record instructions from the user, or other sounds that the user wishes to collect.

10. Graphics tablet: This can be used in a similar way to the keyboard by tapping on icons.

11. Visual display unit: This is predominantly an output device, because it displays requests or information from the computer.

12. Bar code reader: This device may be hand held or static, and is used to capture information from a barcode by using light source, scanner and decoder.

13. INPUT DEVICES

14. Printers: There are different types and sizes of printer but the purpose of each is baisically the same-to produce hard copy of documents, data, information, images and photographs.

15. Plotters: These are machines used in areas such as computer-aided design (CAD) for large and accurate drawings from architectural designs to the latest space probe.

16. Speakers/headphones: These provides the user with audio input. The speakers convert the electronic signals in the sound card to sound waves that can be heard by the user.

17. Braille terminal: This is a specialist reader for visually impaired users. It displays text through individual cells on the terminal, each of which has rounded metal or plastic pins that protrude above the surface of the cells.

18. Modem: A modem converts digital signals generated by the computer into analog signals which can be transmitted over a telephone or cable line and transforms incoming analog signals into their digital equivalents.

19. Network interface card NIC: The NIC contains the electronic circuitry required to communicate using a wired connection (e.g., Ethernet) or a wireless connection (e.g., WiFi). A network interface card is also known as a network interface controller, network adapter, or Local Area Network (LAN) adapter.

20. Terminal adapter: Allows the computer to link into an integrated services digital Network (ISDN)

21. Wireless router: Wireless routers allow multiple computers and other devices, such as smartphones and tablets, to join the same network. While connecting to a router provides access to a local network (LAN), it does not necessarily provide access to the Internet.

22. Wireless network cards: The means by which the computer and other devices are able to recieve and send wireless communication.

23. Hub: Allows multiple computers to communicate over a network. A USB hub allows multiple peripherals to connect through a single USB port.

24. OUTPUT DEVICES