Terms To Remember

·     Bad sectors are unreadable areas on the disk.

·    Cut or cpied text and graphics are stored in the Clipboard brfore being moved to another location.

·    Compressing a file reduces its size and makes transporting between two users easier.

·    Default refers to a predetermined value used by a program when the user does not specify the value. Default setting are ones predetermined by the program and not set by the user.

·    Extension refer to the second part of the filename, which identifies the type or family of the file.

·    File are computerized document that store information in different forms, such as text and pictures.

·    Formatting means dividing a disk into sectors so the disk can store data.

·    My computer displays the contents of the floppy disk drive, the hard disk drive, the CD-ROM drive and the drives on the network.

·    Partitioning eans sections a part of the hard idsk for storage space.

·    Primary name is the first part of a file name. It is the  name by which a file is identified.

·    Changing the names of file or folders is called Renaming.

·    Shortcuts are pointers to a file or folder stored on a hard disk, CD-ROM or floppy.

·    Folder within a folder is called a Sunfolder.

·    Progarms often create .tmp file, or files that are temporarily used for a purpose. These file may accumulate and take up disk space. They should be deleted regularly.

·    Wildcard characters include? and *. They are used to seaech for files when you do not know all of the charachard disk drive

·    Windown Explorer allows you to view the contents of your computer in hierarchical display.it also allows you manage and manipulate the contents of your computer.

          Worksheet are files create in Excel.

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Viewing Contents of Your Computer

My Computer displays the contents of the floppy disk drive,the hard disk drive, the CD-ROM drive and the drives on the network.
To open My Computer:
1.Click Start,and then click My Computer.
   The My Computer windown is displayed. It has two panes, the left pane and the right pane. The left pane contains links to Control panel, My network places and My Documents. It also provides quick access to commonly used system tasks, such add or Remove Programs.
There are two sections on the right pane of My Computer.
a. HARD DISK DRIVES lists the hard disk partitions available on the computer. Here,the hard disk drive has been partitioned into two drives,drive c and drive D.
b.DEVICES WITH REMOVABLE STORAGE lists the floppy drive, CD-ROM drive and other re.movable storage drives, if any.
2. double-click a drive or folder to view its contents.....................

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EXTERNAL STORAGE

A computer’s primary storage or main memory is volatile. This means that the content in memory will be lost when the computer is turned off. Therefore, a permsnent storage area is required to store data and programs that are not needed immediately by the computer. This kind of storage is called the secondary or external storage.

Data stored in a secondary storeage medium is intended to be permanent. Secondary storeage media are inexpensive and have a large capacity to store programs and user data.

Just as you need an audio palyer to listen to an audio cassette,you need a storage device called a drive to write to and read from a storage medium.

Some of the commonly used external storage devices are :

1.Hard disk drives

2.Floppy disk drives

3.Compact disk- Read Only Memory (CD-ROM) 

   drives and CD writers

4.Dgital Video Disk (DVD) drives and DVD

   writers

Hard Disk Drive

A hard disk drive is avery typical exyernal storage device found in almost any PC. The hard disk drive is attached to the system unit from within, but it is possible to remove a hard disk drivefrom a computer if necessary. The storage capacity of hard disks varies up to a capacity of terabytes. Student PCs typically have a capacity of less than 80 gigabytes.

Floppy Disk Drive

The floppy disk drive is an external storage device used to read from and write to a floppy disk.

A floppy disk is a portable storeage medium that can store a small amount of data. The storage capacity of a floppy disk a usually 1.44MB. One disadvantage of a floppy disk is that it is prone to damage by heat, dust and magnetic fields. Example,a simple magntic paper clip may destroy data stored on a floppy disk. For this reason, you should save student records and other important data either on multiple floppy disks or an alternative medium, such as a compact disk. A floppy disk is also called a floppy or diskette.

Compact Disk—Read Only Memory (CD-ROM) Drive

The CD-ROM drive is an external storage device used to read from a CD-ROM. The storage capacity of most CD-ROMs is approximately 650 MB or 700 MB, which is also the reason why large software programs usually come with an installation CD-ROM. The advantage of a CD-ROM is that the datastored on it is less prone to damage because the data present on a CD-ROM cannot be changed.

Rewritable CDs and CD writers

A CD writer is astorage device that can write data to a rewritable CD, which is a special type of CD that allows you to erase the content already stored and store data again. CD-writers are capable of storing a large amount of data on a CD. They are also capable of reading CD-ROMs. Keep in mind that CD-ROMs and rewritable CDs are different media types, they only look the same. People tend to call both CDs.

Digital Video Disk (DVD) Drive

A DVD drive is an external  storage device used to read from a DVD_ROM, although DVD drives are also able to read CDs. A DVD_ROM is similar to a CD-ROM, except that it can store lager amounts of data. DVDs that can store up to 17 GBs are also available. Because of their capacity, DVDs are generally used to stored very large multimedia presentations and movies that combine high quality sound and graphics.

 Comparing Externel Storage Types

A comparison of floppy disks, hard disks, CD-ROMs and DVDs.

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Input/Output devices

There are devices that perform the activities of an input devices in addtition to those of an output device. Such devices are called input/output devices or I/O devices.Modems and network interface cards are examples of input/output devices.

Modem

The term modem stands for modulator-demodulator. Data can be transmitted over different media, such as telephone cables and terrestrial transmission. Telephone cables cab carry waveform called analog signals, analog signals are prone to disturbances from noise and magetic pilses. A relativerly new form of transmission called digital uses binary format (an encoding/decoding system based on 0s and 1s) to send and receive data. This is the format used by computers to send and receive. However, digital signals to cannot be sent through telephone lines. Hence, there is a need to convert the digital signals to analog signals before they are transmitted through telephone cables. Similary, the transmitted data has to be converted to digital signals at the receiving end. A modem is an electronic device used to perform the function of converting the digital signals to analog signals and vice versa.

When you send a massage from  your computer to another computer, the modem acts as an output device. However,when your computer receives a message, the modem acts as an input device. A modem  can be external or internal to the system unit. Modems that are connected to the system unit through cables are called external modems.

Modems are also available as part of system unit. Modems that are built-in to the system unit are called internal modems.

Network interface card

A network interface card (NIC) is a card that is installed in a computer so that it can be connected to a network. Network interface cards provide a dedicated, full-time connection to other computers, for example in a classroom.most network interface cards are designed for a particular type network,although some can serve multiple networks.in classrooms,thmost typical network is Ethernet. Ethernet is a network standard of computer communication using either coaxial or twisted pair cable. Other standards include Tokenring and Framerelay, but these are  less common in classroom environments.

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INPUT DEVICES

In the input-process-output cycle, input for the process should be provided through a device. Devices  used to provide data and instructions  to the computer are called input devices.Some important computer input devices are listed below.·       Mouse
·       Keyboard
·       Scanner
·       Miccrphone
·       Web camera
 Mouse

A mouse is used to point to and select options displayed on the monitor. It is usually connected to the system unit ny means of a long wire.although wireless mouse devices are also increasingly available. A mouse may have two or three buttons. The left button is the most frequently used button. Newer mouse devices called scroll mouse or wheel mouse come with a wheel between theleft and right buttons. This wheel enables you to smoothly scroll through screens of information. Optical mouse is another advanced pointing device that ises a light emitting component instead of the mouse ball. It detects movement my sensing changes in the light reflected by the light-emitting component. Nowadays, wireless mouse devices are also available.

             When you move theon a flat surface,you will see an arrow moving on the screen correspondingly. This arrow is known as the mouse printerIt is good practice to use a mouse pad instead of just any flat surface. A mouse a small mat with a plastic surface and a rubber or plastic-based cushion on which you can move the mouse. It provides greater traction than smooth surfaces and this makes it easier to move the mouse pointer with greater precision. The mouse ball is likely to glide and not roll on smooth glass or wooden surfaces.KeyboardThe keyboard is used for typing text into the computer.lt is also known as the standard input device. A computer keyboard is similar to that of a typewriter,but it has additional keys as well. The most commonly available computer keyboard has 104 keys.There are different types of keys on the keyboard. The keys are categorized as:§      Alphanumeric keys, including letters and numbers.
§      Punctuation keys, such as the colon (J), the semicolon (;), the question mark (?), single quotes (‘) and double quotes (“)
§      Special Keys, such are, control keys and Function keys  (F1 to F12). There keys have different functions depending on where they are used. For example, the enter key starts a new paragraph in aword processor, but in the command line, it executes a command.
 Function keys are special  keys that are used to perform specific functions. They are labeled as F1 F2 F3 and so on, up to F12. The functionality of the keys differs from software. The function of F1 key in most software is to provide kelp with the software.    Software refers to computer instructions or data that can be stored electronically.ScannerA scanner is used to make an exact copy of a picture or a photograph, For example, if you are a creating a report on an event at your school,you can use scanner to scan photographs or logos and insert them into the report.MicrophoneA microphone is a device used to record sound.Microphones convert sound waves into audio signals.Web CameraA Web Camera is a device capable of converting visuals into digital form. When connected to a computer, iy functions as the eye of the computer. You can use it to take a phototgraph of yourself and store it in the computer or for video conferencing.  

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PARTS OF A PC

A computer has various parts and each part performs a specific function. In this chapter, you will learn about some of the important parts of computers and their functions. Some important parts of the computer are shown in Figure. A computer system  unit,often simply called a box, consists of various internet such as motherboard,video card and sound card. Typical external  componets attached to a computer include monitor,keyboard,mouse and printer.Connecting the PCThe followinh points will help you to understand how these parts are connected to each other through cables.§    The system  unit is connected to power supply.
§    The monitor is connected to the system unit and to the power supply. Some monitors draw power directly from the system unit.
§    The keyboraed is connected to the system unit.
§    The mouse is connectedto the system unit.
§    The printer is connected  to the system unit and to the power supply.
§    Other hardware devices, such as scanners and speakers are connected to the system unit and to the power supply.
The Input-Process-Output CycleAny activity, whether simple or comple, follows the basic principle of input-process. For example, consider the simpletask of making tea. The task requires tes leaves, water, sugar and milk as the input. The process includes boiling water,brewing tea leaves, straining and adding milk and sugar. The hot cup of tea that results at the end of the process is the output. Computer also work on the input-process-output principle. Input refers to the data and instructions given to the computer. Process refers towhat the computer does with the data. Output refers to the result of the process. For example, you want the computer to do a simple calculation; the multiplication of tow number 46 and 29. you must first provide the input and specify the process. Here, number 45 and 29 are the input and multiplication is the process. The computer performs the multiplication process on the given inputs. This process results in 1105 as the ouput. INPUT   PROCESS   OUTPUT         

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The Personal Computer

The most popular type of computer used nowadays is the personal computer,referred to as a PC. A personal computer is a computer designed to used by one individual at a time. Individuals and organizations use these computers for applications, such as accounting, statistical analysis and graphic design. However are more powerful computers than PCs for , mainframes and supercomputers.

               Personal computers can be classified into two major categories namely stationary and portable computers.Stationary computers are desktop and tower computers. Portable computer include laptops, handheld computers and Tablet PCs.

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Benefits and Limitations of Copmputers

The benefits of computers to education include higher education satisfaction and higher learning outcomes. Navertheless, computers can truly be beneficial only if users are able to provide accurate and adequate input.Benefits of ComputersSome of the benefits of computers. High speed§ Computers have the ability to perform routine tasks at a greater speed than human beings.They can perform complex calculations in seconds.Teachers can use computers to prepare make lists quickly,instead of preparing them manually.
§  Accuracy
When a task is performed manually, there is always a possibility of human error.Computers can be used to perform tasks in a way that ensures accuracy.      However, if the input given to the computer is incorrect, the output will also be incorrect.    Storage§ Computers can store large amounts of information. After the information is stored, it can be retrieved as needed.you can ues computers to store the details of all the students in the school. You can use the information to perform different kinds of analyses. For example, you might want to track the correlation between your students’ performance and the educational backgrounds of their Parents.
§ Automation
Computers can be indtructed to perform complex tasks automatically. Example ,you want to generate a report showing the average performance of all your student during the previous year, you can use a computer to accomplish this efficiently. Automation canincrease your productivity.§ Diligence
Computers can perform the same task repeatedly and with the same accuracy, without getting tried.§Versatility
Computers can be used to perform both simple and complex task.§ Cost effecitiveness
Computers reduce the amount of paperwork and human effort, thereby reducing costs 

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Digital Communication In Education

With the rapid changes in technology, many educational institutions are using the internet for distance education programs. The internet is an interconnection of thousands of computers across the globe and very powerful communication.Distance educator can use e-mail for sending messages over the internet, gathering feedback, making important announcements and for other communication. Learners can send their feedback and queries through e-mail and receive responses from educators. Education and learners can also participate in newsgroups. There are thousands of newsgroups available on the internet. On a wide variety of topics. E-mail stands for electronic mail. E-mail can be used to send and receive messages over a computer network. A newsgroup is an online discussion forum where the user can post and view messages.School have also started using multimedia during various meetings and functions, such as their Annual Day celebrations, where the annual report, the credits for the play and the honour list are displayed on a huge screen. Similar presentations are also made during parent teacher association meeting. Online Tests and Publishing of Test ResultsStudent can take online tests by using the computer and get results instantly. Several universities post their examination forms on their Web sites. Students can go to the Web site and fill and sibmit the examination form over internet, instead of filling it up on paper and sending it through post. Various universities and school examination boards, such as the central Board of Secondary Education and other state boards, also provide examination results over the internet. Students can thereby view the results within few minutes their announcement. A web site is a location on the world wide web. The world wide web is a system of servers on the internet that support documents formatted in hypert text markup lahguage. HTML is the amin language used to create web pages. A web apge is adocument on the world wide web identified by a unique uniform Resource Locator. 

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APPLICATION OF COMPUTERS IN EDUCATION

In the last few decades,computers have brought about radical changes in our lives. Almost every profession makes use of computers. You will now see how computers are used extensively in the field of education. Digital Media in Education           In addition to conventional chalkboards, teachers of today rely increasingly on digital media. Digital, being attractive and interesting, captivate the young audience. Digital student help student to understand and retain concepts and information.        Students vouch for this new teaching methodology in their classrooms and feel that it is aboon. This is mainly because the teachers are no longer facing the blackboard all the time. Instead, they are able to interact with the students even as the class is in progress and elicit immediate responses to their questions. The interest kindled in the childred also encourages them to be creative, leading to an enquiry based learning process.              With the presence of various multimedia programs, computer based self paced learning is gaining popularity. Computer based tutotial software is also used as teaching aid to supplement classroom learning.Ø     A flexible learning pace is provided so that student can spend ample time learning.
Ø Audio and video help the student to understand the concept clearly, enhance retention and    recall in formation more quickly.
Ø    Complex subjects, such as the human respiratory and cardiovascular systems chemical bonding and chemical reactions, can be taught easily to student through computer based tutorials.
Ø     Immediate feedback is given to the students, which helps them to monitor their progress. 

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What is a Computer ?

In this era of information technology, computers are used in almost all walks of life.computers are wudely used in several fields, such as education, communication, enterainment, banking,business, medicine, weather forecasting and scientific research.        You can use computers to perform a variety of tasks, such as drafing letters, performing calculations, maintaining records about student , creating question paper analyzing exam results and even creating attractive pictures.

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