CHAPTER 48 Information (and Communication) Technology

2 R. Delaney Computers A computer is an electronic device that accepts input, processes it as per a set of instructions and displays the end result as output. Thus there is an input component, a processing component and an output component to a computer.

3 R. Delaney Input Devices USB flash drivesAudio devices CDs / DVDsVideo devices ScannersPointing devices Touch screensKeyboards

4 R. Delaney The Central Processing Unit (CPU) This is often referred to as the brain of the computer. There are three units to it. 1.Control unit controls the rest of the computer so that it will produce the desired results from information inputted and from programmed information. 2.Arithmetic unit processes information and does calculations to arrive at the desired end result. 3.Memory unit stores data and programmes. Memory capacity is measured in bytes. A byte is a unit of storage capable of holding a single character bytes = 1 kilobyte (Kb) = 1 megabyte (MB) = 1 gigabyte (GB)

5 R. Delaney ROM and RAM Computers use two forms of memory: 1.Read only memory (ROM) stores essential programmes for loading the operating system and other basic software packages. It is normally preloaded by the computer manufacturer and cannot be altered or removed. It can only be ‘read’. This memory is permanent and remains on the computer, even after shutdown. 2.Random access memory (RAM) is used by programmes. If you are using memory-intensive software you may require a lot of RAM. RAM is not permanent memory, and information stored there is lost when the computer is shut down unless you save it to the hard drive or a storage device.

6 R. Delaney Commonly Used Software Programmes Presentation packagesDesktop publishing Accounting packagesDatabases Computer Aided Manufacture (CAM) Spreadsheets Computer Aided Design (CAD) Word processing Accountant using an accountancy computer programme

7 R. Delaney The Internet A computer network allows many computers to be connected to each other. This enables them to share common programmes and material provided by a server. The server manages the network and provides information and software to the other computers on the network. A local area network (LAN) is a computer network covering a small geographical area A number of different LANs may be connected to form a wide area network (WAN). The worldwide web (WWW) is a worldwide interconnection between a very large number of network connections.

8 R. Delaney Modems Most computers attached to the WWW receive information that is transmitted over telephone lines. However computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analogue waves. A modem is used to convert digital information to analogue and vice versa.

9 R. Delaney Broadband, Wi-Fi and webcams Broadband Internet normally refers to a high-speed, large-capacity internet connection. Wi-Fi (Wireless Internet) A wireless Internet connection allows a computer to receive signals from a modem without directly connecting it to the computer. The computer receives the signal via the airwaves. Webcams are video cameras that can be connected to or built into a computer to allow you to send and receive video images over the Internet.

10 R. Delaney Computer Applications EFTPOS terminalsEFTPOS facilitiesInternet banking Internet advertisingMail merges to customersOnline bill payments On-line bankingElectronic transfer of money between banks Filing of all household information Video conferencingATM servicesOperation of home alarm systems to customers and suppliers Check credit ratings of (potential) customers Databases from addresses and phone numbers Use accounting packagesProcess loan applicationsInternet shopping Prepare business documents Prepare statementsFamily budgets DatabasesOnline bankingPersonal BusinessBanksHome