Computer Fundamentals (chapter 1)

What is a Computer?

A computer is an electronic device that manipulates information, or "data. It has the ability to store, retrieve, and process data. You can use a computer to type documents, send email, and surf the Internet. You can also use it to handle spreadsheets, accounting, database management, presentations, games, and more.

Whether you realize it or not, computers play an important role in our lives. When you withdraw cash from an ATM, scan groceries at the store, or use a calculator, you're using a type of computer.

Computers Simplified

Inside a Computer -- Part of the Computer Motherboard

For beginning computer users, the computer aisles at an electronics store can be quite a mystery, not to mention overwhelming. However, computers really aren't that mysterious. All types of computers consist of two basic parts:

• Hardware is any part of your computer that has aphysical structure, such as the computer monitor or keyboard.
• Software is any set of instructions that tells the hardware what to do. It is what guides the hardware and tells it how to accomplish each task. Some examples of software are web browsers, games, and word processors.

What are the Different Types of Computers?

There are many types of computers, but personal computers such as desktop and laptop computers are probably the two type of computers that you think of first.

Desktop Computers

Example Desktop Computer


Many people use desktop computers, or desktops as they are often referred to, at work, home, school, or the library. They can be small, medium, or large in style, and usually sit on a desk. The term desktop actually refers to the casing, or the tower. Once you add a monitor, mouse, and a keyboard, you have what is typically known as a desktop computer.


Most desktop computers are easy to upgrade andexpand, or add new parts. In addition to expandability, another benefit of desktop computers is the cost. If you compare a desktop computer with 128 MB of RAM and a 2 GB hard drive to a laptop with the same features, you will most likely find that the desktop computer is priced lower.

The term desktop computer originated when the computer case was wide and flat, and was designed specifically to fit on your desktop with the monitor on top.

Laptop Computers

Example Laptop Computer

The second type of computer that you may be familiar with is a laptop computer, or laptops as they are often referred to. Laptops are battery or AC-powered personal computers that can be easily carried and used in a variety of locations.

A quick glance at the size of a laptop and you might guess that it would be difficult to expand or upgrade. While the desktop computer case is relatively easy to open and access internal components, the small laptop case makes this more difficult in comparison; however, the primary benefit of a laptop computer is its small size and easy portability.

A laptop computer is sometimes called a notebook computer because of its size.

The first electronic computer, the Electronic Numerical Integrator and Computer (ENIAC), was developed in 1946. It measured 18 feet by 80 feet and weighed 30 tons.

Anything you buy for your computer can be classified as either hardware or software. Once you learn more about these items, computers are actually very straightforward.

Types of Personal Computers

iMac all-in-one computerTwo popular types of personal computers are the IBM compatible and Macintosh computers. The first personal computer was produced by IBM in 1981 and was called theIBM PC. In 1984, Apple Computer introduced the Macintosh, or Mac, and it became the first widely sold personal computer with a graphical user interface or GUI (pronounced gooey). Although both IBM and Apple computers are personal computers, the term PC came to refer to IBM or IBM-compatible personal computers.

Apple now produces a Macintosh computer called the iMac, which is a desktop computer that features an all-in-one design. This means all the internal components are located behind the monitor, rather than in a tower case, which is customary in desktop computers.

While our training is intended for people who use PCs and the Windows operating system, some of our information also applies to Macintosh computers.

Other Types of Computers

You may hear someone refer to a computer as a workstation or a server, especially at work. You may wonder how these two items are different from desktop computers.

Workstations are similar to desktop computers, but are more powerful and are usually connected to a network.Servers are specialized computers that store and deliver, or “serve up,” information to other computers on a network.

There are many different types of servers such as file servers, database servers, and web servers. For example, employees at a company might store all the business documents on a file server so that they can share files and access then from any computer on the network. When you use your browser to click a link, a web serverdelivers the page you requested on the Internet, the biggest network in the world.

What is an Operating System?

An operating system is the most important software that runs on a computer. You might be thinking, “OK, but what is software?”Software is any set of instructions that performs some task on a computer. The operating system performs many essential tasks for your computer.

It controls the memory needed for computer processes, manages disk space, controls peripheral devices, and allows you to communicate with the computer without knowing exactly how a computer works. Without an operating system, a computer is useless

The Operating System's Job

Windows Operating System LoadingYou've probably heard the phrase boot your computer, but do you know what that means? Booting is the process that occurs when you press the power button to turn your computer on. At the end of that process, the operating system loads.

From this point, the operating system begins to do its job ofcontrolling the way in which the computer functions. The operating system is responsible for managing the computer's hardware and software resources.

Basically, the operating system serves as the boss, or manager, and makes sure all the various parts of the computer get what they need.

Mac OS LoadingWhen you use your personal computer, you may work on a Word document, print an email, and have your Internet browser open for web surfing, all at the same time. These three programs need attention from the central processing unit (CPU) to do whatever task that you, the user, are telling it to do.

These programs need memory and storage, and need to be able to send messages to devices such as the mouse and the printer to accomplish these tasks.

The operating system is responsible for handling these areas, as well as processor and network management.

What Makes This Job So Difficult?

Let's say you went to your local electronics store and bought language software to learn Spanish. How did the computer programmer who developed the software know that it would work on your computer?

The operating system provides a consistent way for software applications to work on various computers without needing to know specific details about each computer's hardware. It doesn't matter that each computer may have a different amount of memory or processor speed.

Types of Operating Systems

Microsoft Windows, Mac OS X, and Linux LogosOperating systems usually come preloaded on the desktop and laptop computers that you can buy today. Most people use the operating system that comes with their computer, but it is possible to upgrade or even change operating systems.


The three most common operating systems for personal computers are Microsoft Windows, Apple Mac OS X, andLinux.

Start Menu on Windows GUIEach of these operating systems uses a graphical user interface (GUI), which allows the user to interact with the computer. Instead of typing a command that tell the computer what to do, you can use graphical icons and text on the GUI to instruct the computer to perform a task.


For example, if you want your computer to open the browser, Internet Explorer, simply double-click the Internet Explorer icon on the desktop, or select it from the Start menu.


Many users associate the operating system with the GUIbecause this is the part of the operating system that the user interacts with on a daily basis.


Let's take a look at the graphical user interfaces of three 

Microsoft Windows

Microsoft created the operating system, Windows, in the mid-1980s. They have a version of the operating system that is designed for the home user, and a professional version, which is intended for businesses. The versions differ in the depth of networking, security, and multimedia support.

Windows is a proprietary software, which means that Microsoft has placed restrictions on how people can use or copy the software. Windows comes preloaded on most of the PCs sold today, and can also be purchased separately Various versions of the software are priced from $79 to $399 for home users.

Windows Vista Desktop

Microsoft has a big share of the operating system market. According to web analyst Net Solutions, over 90% of computer users have one of the Windows operating systems, such as Windows 98, Windows 2000, Windows XP, or the most recent Windows Vista, as of March 2008.

Windows Vista and Windows XP are often referred to as Vista and XP, respectively.

Visit the Windows section of the Microsoft website to learn more about this operating system.

Apple Mac OS

Mac OS is a line of operating systems created by Apple Inc. The Mac operating system is proprietary software that comes preloaded on all new Macintosh computers, or Macs. The most recent version of the operating system is called Mac OS X (pronounced Mac O-S Ten). Like Microsoft, Apple offers a professional version of the operating system that is intended for use on servers and a version of the operating system that is developed for home users.

Mac OS X Desktop

According to web analyst Net Solutions, Mac OS users account for almost 7.5% percent of the operating systems market as of March 2008. Although the percentage of users is low, especially in comparison to Windows users, Mac operating systems have seen a dramatic jump in growth in 2007. Mac computers are sleek and modernlooking, which has started to appeal to many home users.

Two of the common version names of Mac OS X are Leopard and Tiger.

To learn more about the Macintosh computers visit the Apple Inc. website, and explore the Mac computers available, as well as the Support center for information about the Mac OS.

Linux

Linux is an open source, or free, operating system. Unlike Windows and Mac OS, Linux is not proprietary software and all the computer code that is part of the operating system can be used and modified by any user. Linux was started in the 1990s when Linus Torvalds, a person interested in creating a free operating system, developed the Linux (pronounce lynn-ux) kernal, which is computer code that is a central part of an operating system.

As an open source software, any individual or company can take the Linux kernal and modify and add to it. Hundreds of companies and individuals have taken the Linux kernal and added additional computer programs to create various versions of the Linux operating system. These versions are known as distributions and are available to download for free.

Ubuntu Desktop: A Version of Linux

Linux is extremely popular in businesses, especially for servers, because it is adaptable. According to Net Application statistics, Linux represents under 1% of the market share for home users, but it does offer an alternative to commercial operating systems.

Despite being used in many businesses for servers, you do not have need to have special programming skills to download and use Linux. In fact, if you want to try Linux, you don't have to actually install it on your computer. Several versions of the operating system can be downloaded and burned to a CD.

To learn more about Linux and how this open source software works, visit Linux Online.

Two popular distributions of the software are Ubuntu and Red Hat. Ubuntu is completely free and is available in a version geared specifically for home users. Red Hat is a company that offers technical and training support for businesses that use its version of the operating system, Red Hat Linux.

What are the Basic Parts of a Desktop Computer?

All of the basic parts of a desktop computer are considered hardware. The computer case, monitor, keyboard, mouse, andpower cord are considered the basic parts. These items are the things you notice right away when you look at a desktop computer. 

Beyond these parts are the hardware items that are located inside the computer case and the peripherals, which are optional pieces of hardware that make the computer system more useful, or enable you to accomplish additional tasks. Let's take a look at the basic hardware components, or the things required in order to let you and the computer interact.

Basic Parts of a Desktop Computer (cont.)

Computer CaseComputer Case
The computer case is the metal and plastic box thatcontains the main components of the computer. It houses the motherboard, central processing unit (CPU), the power supply, and more.

Computer cases come in different shapes and sizes. Adesktop case lies flat on a desk, and the monitor usually sits on top of it. A tower case is tall and sits next to the monitor or on the floor. The front of the case usually has an on/off switch and two or more drives.

Most of the personal computers you can purchase today include tower cases, rather than desktop cases; however, some computers are being made with all of the internal components built into the monitor, which completely eliminates the tower.

Basic Parts of a Desktop Computer

Computer with Two LCD MonitorsMonitor
The monitor works with a video card, located inside the computer case, to display images and text on the screen. The two main types are cathode ray tube (CRT) and liquid crystal display (LCD) monitors.

The CRT monitor is big, like a tube television, and takes up a lot of desk space; however, it is the least expensive monitor option. The LCD monitor is thin and saves energy, but costs more. Over the years you can expect to see fewer CRT monitors as LCD monitors become the standard.

Your monitor has an on/off button and control buttons that allow you to change your monitor's display. Control buttons are either visible or located behind a small panel. Additionally, some monitors have built-in speakers.

Power Cord
The power cord is the link between the power outlet and the power supply unit in the computer casing. If the power cord is not plugged in, the computer will not power on. It is a good idea to keep the power cord plugged into an Uninterruptable Power Supply (UPS), which serves as a surge protector with its own temporary power source.

Basic Parts of a Desktop Computer (cont.)

Computer with Two LCD MonitorsMonitor
The monitor works with a video card, located inside the computer case, to display images and text on the screen. The two main types are cathode ray tube (CRT) and liquid crystal display (LCD) monitors.

The CRT monitor is big, like a tube television, and takes up a lot of desk space; however, it is the least expensive monitor option. The LCD monitor is thin and saves energy, but costs more. Over the years you can expect to see fewer CRT monitors as LCD monitors become the standard.

Your monitor has an on/off button and control buttons that allow you to change your monitor's display. Control buttons are either visible or located behind a small panel. Additionally, some monitors have built-in speakers.

Power Cord
The power cord is the link between the power outlet and the power supply unit in the computer casing. If the power cord is not plugged in, the computer will not power on. It is a good idea to keep the power cord plugged into an Uninterruptable Power Supply (UPS), which serves as a surge protector with its own temporary power source.

Basic Parts of a Desktop Computer (cont.)

Keyboard
The keyboard is a piece of hardware that resembles a typewriter keyboard. It is one of the primary ways we communicate with the computer and enter data. There are many different types of computer keyboards such as wired, wireless, ergonomic, multimedia, and more. Although there may be differences in the location of some keys or features, keyboards are very similar and allow you to accomplish basically the same tasks. The images below show you three different types of keyboards.

Standard KeyboardAbout the Keyboard

• The main part of a computer keyboard has alpha-numeric (letter and number) keys similar to a typewriter. However, the keyboard also features keys that cause the computer to perform specific tasks.
  
• The Escape key, labeled Esc, allows you to stop a function or action. For example, if your computer suddenly freezes up, you may be able to resume by pressing Esc.
  
• The Function keys, along the top of the keyboard, are labeled F1, F2, up to F12. These shortcut keys allow you to quickly complete a specific task within certain programs. For example, F1 opens Help in Microsoft Office.
  

Wireless Ergonomic Keyboard

• The Print Screen, Scroll Lock and Pause/Break keys are at the far right end of the keyboard. The Print Screen key takes a "picture" of your screen that you can edit or save using a graphics program.
  
• The Enter key carries out commands. For example, while on the Internet, you can type in a website address, called a URL, and press Enter to go to the site.
  
• The Control (Ctrl), Alternate (Alt), and Shift keys are designed to work with other keys. For example, if you press Ctrl + S at the same time, you can save a file.
  
• The Backspace key erases the character to the left of
  the cursor.
  

iMac USB Keyboard

• To the right of the regular keys is the cursor control pad. At the bottom are four arrow keys. Pressing any one of these keys moves the cursor in the direction of the arrow.
  
  Depending on the keyboard you are using, there arefive to six keys above the arrows including:
  
  • The Delete key erases the character to the right of the cursor.
  • The Insert key switches between the insert mode and overtype mode. The insert mode is the normal mode for word processing.
  • The Home key moves the cursor to the left or beginning of the current line.
  • End moves the cursor to the right end of the current line.
  • Page Up and Page down take you to the top or bottom of the screen.
• The Number pad, at the far right end of the keyboard, resembles a calculator keypad. Similar to the cursor keys, you can use the arrow keys on this keypad to move the cursor.

Basic Parts of a Desktop Computer (cont.)

MouseMouse
The mouse is a peripheral that is known as a pointing device. It lets you point to objects on the screen, click on them, and move them. Previously, it was considered an optional device, but now all desktop computers will come with a mouse.

There are two main types of mice -- optical and mechanical. The optical mouse uses an electronic eye to detect movement and is easier to clean. The mechanical mouseuses a rolling ball to detect movement and is more difficult to clean; however, it is less expensive, so many computers come with a mechanical mouse.

Another decision you have when choosing a mouse is wired versus wireless. Wireless everything is popular right now, so it will be up to you to decide which type will work best for you.

To properly use the mouse:

• Using your right hand, place your thumb on the desk or table top on the left side of the mouse
• Your index (pointer) finger should rest on the left button of the mouse.
• Place your middle finger on the right button of the mouse.
• Your ring finger and little finger should rest on the right side of the mouse.
• The base of your wrist should rest on the mouse pad or desktop, for stability.

Left-handed computer users sometimes use their right hand to maneuver the mouse. However, if you're left-handed and want to use your left hand, the mouse buttons can be switched.

To Switch the Mouse Buttons for a Left-Handed User:

• Click Start.
• Choose SettingsControl Panel.
• Double-click the Mouse icon in the Control Panel window.
• Click Left-handed.
• Click OK.

To properly use the mouse:

• Click. Select an object on the screen by pressing the left mouse button down with your index finger and then release the button.
  
• Drag an object on the screen by pressing and holding down the left mouse button with your index finger while moving the mouse. When the object is where you want it, release the button.
  
• To double-click, rapidly press and release the left mouse button with your index finger.
  
• To right-click, press and release the right mouse button with your middle finger.

A trackball is similar to a mouse, but the ball that helps maneuver the cursor is on top instead of underneath.

introduction to computers video

Introduction to computers ppt

 

• Questions for first chapter
•  

UNIT–I FUNDAMENTAL OF COMPUTER

1.      Define computer.

2.      Explain in brief the generations of computers. (OR) Explain briefly how the computers are classified according to generations.

3.      Draw the block diagram of a digital computer and explain briefly the functions of each block.

4.      What is the full from of ALU? What functions are performed by the ALU? (OR) What does the ALU stands for and states the functions of it.

5.      What do the letters CPU stand for? What are the main components of a CPU? (OR) List the major functional blocks of CPU.

6.      State (or what are) the functions of CPU. (OR) Describe the functions of CPU.

7.      Define bit and byte.

8.      What is a word length? How it is expressed? (OR) Write about word length.

9.       Define each of the following: (a) Byte (b) Kilobyte (c) Megabyte (d) Gigabyte

10.  Explain generations of computers.

11.  Explain briefly the classification of computer based on size and processing capability.

12.  What are the different types of memory? Explain each. (OR) List and explain the types of memories used in computer.

13.  Explain ROM and RAM.

14.  Distinguish between ROM and RAM.

15.  Write a short note on Cash memory. (OR) State the important of a Cash memory.

16.  What is the purpose of an input device? List any four input devices.

17.  What is the purpose of an output device? List any four output devices.

18.  Explain the use of secondary storage devices.

19.  What are the differences between Primary storage and Secondary storage? (OR) Distinguish between Primary storage and Secondary storage.

20.  How many binary digits are there? Which symbols are used for them? What are they usually called?

21.  Why do digital computers use the binary number system for their operations? Explain.

22.  What is meant by the base of a number system? What is the value of the base for decimal, binary, octal and hexadecimal number system?

23.  Why do we say that our decimal system uses a base of 10 while the binary system uses a base of 2?

24.  What are the octal and hexadecimal number systems? How are binary digits converted to octal or hexadecimal?

25.  Give the full form of the following addrevations: BCD, ASCII, and EBCDIC.

26.  What is the full form of ASCII? What is the purpose of the ASCII code?

27.  What are the computer codes? State the purposes of each.