OFFICE AUTOMATION – I MODERN OFFICE EQUIPMENT 12. COMPUTERS AND THEIR BASIC OPERATION Computers are something that have become a part of our lives. In the past 15 years, from a device that was used by scientists and researchers, computers have invaded the average man’s life, and it is difficult to think of any job where they are not used. This lesson introduces you to the basic components of a computer system, how they can be used, and how to switch on and switch off a computer.
12.0 Objectives After going through this lesson, you will be able to: • • • •
Identify the basic components of a computer. Identify some of the most popular input/ output devices connected to a computer. Understand how the different components and devices work together. Be able to switch on and shut down a Windows-based computer.
12.1 Introduction It has become necessary to know how to use a computer today. Whatever work you may do, the ability to use a computer effectively will add to your success. This lesson will help you learn to identify the basic components of a computer, and how to use some of the most common devices that are connected to the computer. In this lesson, you will learn how to identify individual parts of a computer, switch a computer on, log in, and shut down a computer after you’ve finished your work. Each of these tasks is very short and simple, but special names are given to each to make it easy to refer to them. You should become familiar with each, to be able to understand and use them in your professional life.
12.2 History of Computers In the past 30 years, computers have developed extremely quickly, in phases that are called ‘generations’. The First Generation of computers used valves;
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the Second Generation introduced transistors, that were more efficient and cheaper. The next development in the early sixties, when hundreds of transistors started getting put on a single silicon chip, which is called an ‘integrated chip’ and became the basis of the Third Generation. Finally, the Fourth Generation introduced very large scale integration (VLSI), where thousands of transistors could be placed on a single chip. The most popular form of the computer today, and the one on which we will be focusing in this lesson, is the Personal Computer. The PC is small in size but capable enough to handle large tasks. It can perform a diverse range of functions from keeping track of household accounts to keeping records of the stores of large manufacturing companies.
Self-Check Questions 1. What is the most popular form of the computer today? 2. Modern computers are based on what fundamental building block, introduced in the Second Generation and improved significantly since then?
12.3 Switching On a Computer Switch on the UPS/ stabilizer or other device feeding power to the computer system. Switch on the monitor first; you’ll find a button on the lower front right edge of the device. This button is a toggle; pressing it once switches the device on, the second time switches it off. Next, switch on the computer itself. You’ll find that the front has a number of buttons; the buttons are located in different locations, but always on the front panel. The ‘Power’ button is usually the largest button, and is prominently placed. It is sometimes marked with a lightbulb image, to denote it is the power button. Another smaller button for resetting the computer may also be present. If you press that button, it is equivalent to switching the computer off and switching it on again. After you’ve switched the computer on, you’ll find that the small light on the monitor changes colour from yellow/ amber to green, and a display appears. You don’t need to do anything more until all activity stops, at which time you will either be on the login page, or on the Windows screen, ready to work. We’ll cover the login page and process in the next section.
Self-Check Questions 3. What is the colour of the light on the monitor once the computer is switched on?
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12.4 Using the Keyboard The image below is that of a keyboard with certain keys marked out.
Function keys are special purpose keys whose function depends on the software being used. These are the keys on the top. Until you know more about these keys, you should not use them. Cursor keys are used to move the cursor up, down, left, or right. These are the four arrow keys to the lower right. You may need to use these keys in some of the application software you’ll use later; for now, you should just remember that these are the cursor keys. Use the ‘backspace’ key (the key with a backward pointing arrow) or the ‘Del’ key to delete whatever you’ve typed. If the ‘Num Lock’ key is pressed, the set of keys on the right hand of the cursor keys act like a calculator. If this is the case, the ‘Num Lock’ light on the top right of the keyboard will be on. The rest of the keys act like they would on a typewriter. If you keep ‘Shift’ pressed while pressing another key (say, ‘j’), capital ‘J’ will get typed. If the other key you press has two characters on it, (eg, ‘/’ and ‘?’), pressing ‘Shift’ while pressing the key will lead to the second character getting typed. Pressing ‘Caps Lock’ locks the keyboard into ‘Shift’ mode until you press ‘Caps Lock’ again. It would be best to experiment with the keyboard when you start learning Word, Notepad, or any other Word Processing application later in this course.
Self-Check Questions 4. Where is the ‘Del’ key? What happens if you press it?
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12.5 Using the Mouse The image on the right is that of a ‘mouse’. The grey wheel in the middle is called the ‘scroll’ wheel. You can scroll up and down by rolling the wheel in applications with more than one page. There are two buttons on the mouse – one to the left of the scroll wheel, and the other to the right of the scroll wheel. These are, respectively, called the ‘left button’ and the ‘right button’. To press and release the left button once is called to ‘left-click’, or simply, ‘click’. To press and release the right button is to ‘right-click’. To press and release the left button twice in quick succession is to ‘double-click’. These terms will be used on numerous occasions during later lessons to guide you on how to tell Windows what you’d like to do. You’ll find an arrow on the monitor, which moves when you move the mouse. This is the ‘pointer’. You move the mouse to move the pointer and ‘point’ to whatever you want to do, and then click, double click, or right-click the mouse buttons to give different commands. These are things you will be doing in later sessions.
Self-Check Questions Fill in the Blanks 5. Pressing and releasing the left mouse button once is called a ________ 6. To press and release the left button twice in quick succession is to ________
12.6 Logging In Logging in is an optional process. Earlier Operating Systems like Windows 95, 98 and Millennium Edition usually started without any request to log in. Even Windows 2000 and XP may or may not require you to log in. However, if required, this is what you need to do to complete this process. First, make sure you have a user ID and password for the computer. If you don’t know, ask your system administrator or other person who uses the machine on a regular basis.
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Next, when the computer has finished booting, you’ll find the monitor has a screen where you have to enter your user ID and password. In Windows XP, this is what the screen looks like:
In older operating systems, you will have to type in the user ID yourself. In those operating systems, the login process starts by pressing Ctrl + Alt + Del (Hold down Ctrl and Alt keys together, and press Del). A new screen will come up where you can enter your user ID and password, and press enter. Alternatively, if you see a screen like the one above, you can just click on the user’s name, and the system will ask you for the password and log you in. The computer will load your specific preferences and desktop and then await your inputs. This is what the Windows XP desktop looks like; earlier Operating Systems did not have the 3D look and feel, but were otherwise very similar.
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Desktop
Icon
System Tray
Start Menu
Quick Launch Menu
Task Bar
Date and Time
Self-Check Questions Fill in the Blanks 7. The two essentials for logging in are ______________ and ______________
12.7 Shutting Down Other lessons will guide you through using the basic Office applications like Word and Excel, but after completing your work, you need to shut the computer down. 1. Move the mouse so that the pointer is on the lower-left edge of the screen, where it says ‘Start’. Click ‘Start’. 2. On the screen that opens, click the following image:
3. You’ll get the following screen:
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Click ‘Turn Off’, and the computer will turn itself off after a couple of minutes.
Self-Check Questions Answer True or False 8. If you just switch off the computer without shutting it down, it may damage the computer
12.8 Summing Up In this lesson, we discussed the various components that make up a computer (monitor, keyboard, mouse, printer), with photographs of sample devices. We also looked at how they are used. We talked about the various Generations of Computers shortly, and then walked through the process of switching on and shutting down the computer, with relevant screenshots. You would do well to find a computer and try out what you have learnt today, so that the learning is internalized.
12.9 Answers to Self-Check Questions 1. 2. 3. 4. 5. 6. 7. 8.
Personal Computer Transistors Green. Top-right edge of the keyboard. Whatever was typed immediately to the left of the cursor will be deleted. Click. Double-click. User ID and password. True
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12.10 Terminal Questions 1. 2. 3. 4.
What is a ‘mouse’, and how would you use it What was the Fourth Generation of computers How would you log into the computer How would you shut the computer down
12.11 Glossary Monitor: Display consisting of a device that takes signals from a computer and displays them on a CRT screen. Keyboard: Device consisting of a set of keys, used with a computer. Mouse: A hand-operated electronic device that controls the coordinates of a cursor on your computer screen as you move it around. Dot Matrix Printer: A printer that represents each character as a pattern of dots from a dot matrix. Very cheap to use, usually only black and white, and not very good at printing graphics. Inkjet Printer: These printers work by spraying ink onto the page. They are able to print in full-colour, and are able to print in highquality graphics. Per page cost of printing is much higher than a dot matrix printer. Laser Printer: These printers work on the same principle used by photocopy machines. A laser beam heats up the surface of the paper, and the ink bonds to those heated areas. Laser printers have high-quality printouts, and per page printing cost is also low. However, these printers are more expensive, and usually print only in black and white. Colour laser printers are available, but more than 25 times as expensive as inkjet printers. Hardware: All the ‘hard’ parts of the computer, which are basically all the components and devices that you can see, touch, and feel, are collectively called ‘hardware’. Hardware alone is of no use, without electricity and software. Software: All the programs that one uses on the computer, which are nothing more than collections of logic and functionality that do different things based on the inputs the user gives, are collectively called software. Software needs hardware to be able to do anything.
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Operating System: The Operating System is the name given to that special program that directly interacts with the hardware. All other programs/ software (called ‘Application Software’) interacts with the Operating System, which in turn interacts with the hardware. Users usually interact only with Application Software. Boot: Windows-based computer systems need to be ‘booted’ to be able to work. The process of booting ‘reads’ the Operating System program (in this case, Windows) into the computer’s memory and makes it available for use. Logging in: The process of logging in helps the computer know which specific user is going to be using the computer, and in loading the user-specific settings that may have been saved earlier. This process also makes sure that no unauthorized person uses the computer. Memory: Memory is of two types – RAM (Random Access Memory), and permanent storage (usually on a device called a ‘hard disk’). RAM is much faster and is where the Operating System keeps whatever application program is being used. However, RAM gets wiped clean whenever the electricity is switched off, which is where the hard disk is required. All data that needs to be saved for future use needs to be ‘saved’ or ‘written’ to the hard disk for it to be available in future. Shut Down: Advanced Operating Systems like Windows have a number of features that help them respond faster to users. However, this leads to a need to be ‘shut down’ rather than being directly switched off. ‘Shut Down’ is a process where data which is in RAM is saved for future retrieval. Switching off the power without shutting down a computer is very risky, and could lead to errors in the computer since whatever is in RAM will be lost when the electricity is switched off.
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