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Contents 1. History of Computer... 3 2. Generation of Computer... 6 3. Computer & Peripheral... 9 4. Hardware... 12 5. Software... 15 6. Working into the Computer Room... 17 7. Keyboard... 19 8. Exploring Computer Memory... 23 9. Toolbars... 25 10. Working With Paintbrush... 27 2 Eduheal Foundation Class - 3 & 4
History of Computer History of the computer started about 2000 years ago with the invention of Abacus. The need was to enhance the speed of calculations. The Abacus Abacus is a wooden rack holding two horizontal wires with beads strung on them. When these beads are moved around according to the programming rule memorised by the user, all regular arithematic problems can be done. Napier s Bones History of Computer Napier s Bones is an abacus created by Sir John Napier, a great mathematician of Scotland. This was a manual device and invented in 1617 AD. It was made of bones and rods. It was capable of doing all the four mathematical operations - addition, subtraction, multiplication and division. The Pascaline or Pascal s Calculator The pascaline was the first mechanical calculator invented by a French mathematician, Blaise Pascal in 1642 AD. It was also called Pascal s calculator. This machine was capable of doing addition and subtraction with a high speed. It worked on the principle of clock work mechanism. This machine consisted of chain and toothed wheels. The teeth on each wheel represented numbers from 0 to 9 from right to left and each wheel represented units, tens, hundreds, thousands, ten thousands and so on. This device was used everywhere and, became very popular in a short period because of its speed and accuracy. Eduheal Foundation Class - 3& 4 3
Leibnitz Calculator Just after a few year after Pascal, the German mathematician, Gottfried Leibnitz in 1671 managed to build a four function calculator. This was an improvement over the Pascaline. This machine was also able to perform multiplication and division. Leibnitz s machine used stepped cylinder, each with nine teeth. This machine was also called stepped reckoner. Jacquard s Loom Jacquard loom is a mechanical loom invented by Joseph Marie Jacquard in 1801. This was the first machine to use punch cards to control a sequence of operations. Although it did no computation based on them, it is considered an important step in history of computing programming. Difference Engine The difference engine might be considered to be a computer in the modern sense was conceived in 1822 by British Mathematician Charles Babbage. Difference engine can automatically calculate the mathematical tables. Accurate parts of this engine could not be made because the technology at that time was not so developed. Babbage had to leave his project after spending a huge amount. The difference engine was only partially completed when Babbage conceived the idea of another sophisticated machine called Analytical Engine. Analytical Engine This was the fully automatic calculating machine. Only part of the machine as a trial piece was completed before Babbage s death in 1871. He started its designing in 1833. This machine besides performing all four mathematical operations can do some logical operations also. Babbage included the concept of control processor, storage area and input-output devices in design. It had almost all the parts of a modern computer. His great inventions of these two engines earned Charles Babbage the title of Father of Modern Computers. 4 Eduheal Foundation Class - 3 & 4
Hollerith s Machine This machine was developed by an American, Herman Hollerith in 1887. It was the first electromechanical punched card tabulator. He used punched cards for input, output and instructions. The machine consisted of three main parts. A card reader that reads the holes in the cards. A gear driven mechanism that can count A wall of dial indicators to display the results of the count. This machine was used by American Department of Census to compile their 1890 census data. It helped it to complete the task within 3 years which took 7.5 years earlier and saved 5 millions dollars. Hollerith built a company, the Fabulating Machine company which, eventually became International Business Machine, IBM. Mark - I It was the first machine, which could perform according to pre-programming. It was the first computer and was also known as Automatic Sequence Controlled Computer (ASCC). 1. Arrange the following in sequence: (i) Hellerith s Machine (iii) Leibnitz Calculator (v) The Pascaline ACTIVITY (ii) Jacqard s Loom (iv) The Abacus 2. Which machine was developed by Charles Babbage? (i) Leibnitz Calculator (iii) The Abacus (ii) Analytical Engine 3. Which of the following work on clocks work mechanism? (i) Pascaline (iii) Mark I. (ii) Napier s Bone Eduheal Foundation Class - 3& 4 5
The history of computer development is often referred to in reference to the different generations of computing devices. Each generation of computer is identified by a major technological development that fundamentally changed the way computers operate, resulting in increasingly smaller, cheaper, more powerful and more efficient and reliable devices. Following are the generation and the developments that led to the current devices that we use today. First Generation-1940-1956: (Vacuum Tubes) The first computers used vacuum tubes (about 18,000) for circuitry and magnetic drums for memory. They were very expensive to operate and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions. First generation computers relied on machine language to perform operations. They could only solve one problem at a time. Input was based on punched cards and paper tape, and output was displayed on printouts. These were huge device and occupied large space. These were 5000 times faster than Mark I. The UNIVAC and ENIAC computers are examples of first-generation computing devices. Second Generation - 1956-1963: Transistors Generation of Computer Transistors replaced vacuum tubes and ushered in the second generation of computers. The transistor was far superior to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy-efficient and more reliable than their first generation predecessors. Though the transistor still generated a great deal of heat that subjected the computer to damage, 6 Eduheal Foundation Class - 3 & 4
it was a vast improvement over the vacuum tube. Second generation computers still relied on punched cards for input and printouts for output. Second generation computers moved from cryptic binary machine language to symbolic, or assembly languages, which allowed programmers to specify instructions in words. High-level programming languages were also being developed at this time, such as early versions of COBOL and FORTRAN. These were also the first computers that stored their instructions in their memory, which moved from a magnetic drum to magnetic core technology. The first computers of this generation were developed for the atomic energy industry. Third Generation - 1964-1971 (Integrated Circuits) The development of the integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers. Instead of punched cards and printouts, keyboards, monitors and operating system were used. It became possible to run many different applications at one time with a central program that monitored the memory. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors. Fourth Generation - 1971-Present (Microprocessors) The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip. In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. As these small computers became more Eduheal Foundation Class - 3& 4 7
powerful, they could be linked together to form networks, which eventually led to the development of the Internet. Fourth generation computers also saw the development of GUIs, the mouse and handheld devices. Fifth Generation - Present and Beyond (Artificial Intelligence) Fifth generation computing devices, based on artificial intelligence, are still in development. Though there are some applications, such as voice recognition that are being used today. The use of parallel processing and superconductors is helping to make artificial intelligence a reality. Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. The goal of fifth generation computing is to develop devices that respond to natural language input and are capable of learning and selforganization. ACTIVITY 8 Eduheal Foundation Class - 3 & 4
Computer & Peripheral Monitor A monitor (Visual Display Unit) is the screen on which words, numbers, and graphics can be seen. The monitor is the most common output device. Compact Disk Some compact disks can be used to put information on it. This is called burning information to a CD. Note : A CD can also be an input device. Printer A printer prints whatever is on the monitor onto paper. Printers can print words, numbers, or pictures. The popular printer are Dot Matrix, Inkjet and Laser Printer. Inkjet printers are the most popular printers for colour prints. Laser printer is the fastest and costliest. The print quality is very clear and sharp. Speaker A speaker gives you sound output from your computer. Some speakers are built into the computer and some are separate. Disk Drivers A disk drive is used to record information from the computer onto a floppy disk or CD. Floppy Disk A floppy disk is used to record information on the floppy disk and can be used later or used on another computer. Headphone Headphones give sound output from the computer. They are similar to speakers, except they are worn on the ears so only one person can hear the output at a time. Eduheal Foundation Class - 3& 4 9
Keyboard The keyboard is a way to input letters or numbers into different applications or programs. A keyboard also has special keys that help operate the computer. Microphone Mouse The mouse is used to open and close files, navigate web sites, and click on a lot of commands (to tell the computer what to do) when using different applications. A microphone is used to record sound. The sound is then saved as a sound file on the computer Scanner A scanner is used to copy pictures or other things and save them as files on the computer. ACTIVITY = scan = computer = file = picture = save = printing = emailing = the web When you, you make a of your. You need different setting for, or. Always your. Translate the above sentence: 10 Eduheal Foundation Class - 3 & 4
Joystick A joystick is used to move the cursor from place to place, and to click on various items in programs. A joystick is used mostly for computer games. Touch Screen A touch screen is a computer screen or other screen that you can touch with your finger to enter information. Examples of touch screens include a smart board, a microwave, a dishwasher, or an ATM at a bank. Bar coding Bar Code Scanner A bar code scanner scans a little label that has a bar code on it. The information is then saved on the computer. Bar code scanners are used in libraries a lot. Modem It is modulator and Demodulator. This device is used to convert the digital signals into analog signals that can be carried through telephone lines to any place. And once again, it is used to convert analog signals to digital signals. MODEM works as a mediator between two or more computers Connect the Modem to the computer: ACTIVITY Eduheal Foundation Class - 3& 4 11
Hardware All the solid equipment of the computer that you can touch are called hardware. Hard is the parts that go together to make a computer. You can touch these equipments. Use list words to name the hardware ACTIVITY headphones printer speakers system unit monitor keyboard mouse scanner 12 Eduheal Foundation Class - 3 & 4
ACTIVITY How can you tell what parts are hardware? Crack the code to find out: a b c d e f g h i j k l m 1 2 3 4 5 6 7 8 9 10 11 12 13 n o p q r s t u v w x y z 14 15 16 17 18 19 20 21 22 23 24 25 26 8 1 18 4 23 1 18 5 9 19 20 8 5 20 8 9 14 7 19 20 8 1 20 25 15 21 3 1 14 19 5 5 1 14 4 20 15 21 3 8 2 5 3 1 21 19 5 9 20 9 19 8 1 18 4 : Eduheal Foundation Class - 3& 4 13
Name all of these items. Then write the circled letters below. They will tell you what all of these items are. H S M K C W r i t e r C P S All these items are you can t and f them all. 14 Eduheal Foundation Class - 3 & 4
Software Software is a part of the computer that cannot be seen or touched. If hardware is the body, then software is just like the soul in our body. As the body cannot live without the soul, computer cannot perform without software. You can also compare it with human brain. Brain always works and controls our body. In the same way software works and controls the computer. A set of instructions for a particular work given to the computer is called program. Software is a set of programs. Each software is used for a particular type of work. For example, we can type letters by using the software-ms Word. We can draw pictures by using the software-corel Draw. We can make financial statements by using the software-microsoft Excel. Some more examples are: Notepad, Paintbrush, Power Point etc. It doesn t matter what a program does, it is still called S Find these software words : Excel Games Microsoft PowerPoint Software Paint Programs Word Eduheal Foundation Class - 3& 4 15
ACTIVITY Draw a Red circle around all the software and a green circle around the parts which are not? Write A. B. C. or D. to choose the best program for the work below: A. Word B. Excel C. PowerPoint D. Paint Draw a picture for your Mum. Write a story for your teacher. Count how many cars you see each day. Show pictures of your holiday. Count how much money you spend at the canteen. Practise your typing. Present facts about the ocean. Draw a picture of fish. Write a letter to your Grandpa. 16 Eduheal Foundation Class - 3 & 4
Working In The Computer Room Computer are fragile and costly. Always treat you computer with care. Some points needs to be remembered while using computer at your school or home. Remember to wash your hands! If your hands are dirty, when you touch the computer you will make the computer dirty. Having clean hands help to keep your computer clean too Never use chewing gum, bubble gum and any other stickly things in your computer room as it can damage the computer system. Remove you shoes outside the computer room as dirt is harmful to the computer. Always enter in the computer lab quitely. If you have a drink near your computer, it could spill! That would spoil the computer. If you eat food at the computer, crumbs will get inside the keyboard and the mouse and they won t work the way they are supposed to. Its important to eat food away from the computer and leave the computer table just for working on the computer. Fingerprints on the screen make it hard to see. The screen also has a special coating on it so you have to use special cleaner on it. Regular cleaner will hurt the screen. LCD (thin panel monitors) are especially delicate and can be easily ruined by fingers touching and poking at them. Make sure to keep your fingers off the screen to keep from damaging it and to help it last a long time. Eduheal Foundation Class - 3& 4 17
Be sure to keep all magnets away from computers and disks. Even your refrigerator magnets can damage the data on a disk. Don t let them near your computer area. Sometimes, things don t go our way when we are working on a computer. We should remember that computers are fragile and to always treat them with care. Mistakes on computers can almost always be fixed while broken computer components cost money to replace. Always ask permission from your parents or teachers before using the computer. Using the computer improperly could cause you to lose the privilege of using the computer at all. Remember to update your Anti-Virus software. New viruses come out each day that could harm your computer. Keeping your anti-virus information current (latest) could save your computer from getting sick. Also, beware of downloading any file that isn t from a reputable source. Even the cutest screen savers could have a virus hidden inside that will harm your computer. Booting Up Once you enter the computer room you make the computer ready to use for doing work. This is called booting up. Switch on the Power Supply Button Wait for the message on the monitor Switch on the UPS Then wait for the cursor on the monitor screen Switch on the Monitor Computer is ready to work 18 Eduheal Foundation Class - 3 & 4
Keyboard Although a computer keyboard is based on the old typewriter layout, there are some major differences in the ways that keys are used. Computer keyboards also have additional keys. Learning to use the unique keys and special functions of the computer keyboard can save your time and make you more comfortable with your computer. Function Keys (F Keys)... Most computer keyboards have a row of Function keys at the top of the keyboard. These keys are marked F1 through F10 or F12. While they were widely used with older DOS programs, they are not as popular today. As a short cut F2 is used to rename a folder/file. Return or Enter Key This key is usually marked Return or Enter, but some times it is labeled with only a large arrow. This key is used to enter commands or to move the cursor to the beginning of the next line. There is a second Enter key on the numeric keypad. This functions exactly like the larger Enter key near the alphabet letters. Escape Key The Escape key, which is marked ESC on most keyboards, is basically used to exit or escape from programs and tasks. In many cases, it will have no Eduheal Foundation Class - 3& 4 19
effect at all. However, it can sometimes get you out of trouble by making the computer go back or escape to a previous screen. Control Key (Ctrl) The Ctrl key is used in association with another key. Holding it down while pressing another key will initiate a certain action. Ctrl key combinations are defined by the application that is being used. Some, however, have become a standard that most programs follow. For instance in most Windows programs, Ctrl+S will save the current file or document, and Ctrl+P will print the current file or document. Alternate Key (Alt) Like the Control Key, the Alt key is used in combination with other keys. In most Windows programs, each of the menu choices at the top of the screen has one letter underlined. Holding down the Alt key while pressing the key corresponding to the underlined letter will open the menu just as though you had clicked your mouse on that menu choice. For instance, if the menu shows the choice File, you can open that menu by clicking the mouse on the word File or by pressing the Alt + F i.e. Alt key and the F key simultaneously. Caps Lock The Caps Lock key is a toggle key. Pressing it once turns it on. Pressing it again turns it off. Some computer keyboards have a light or indicator that shows when the Caps Lock is on and when it is off. When Caps Lock is on, every letter that is typed will be a capital letter. Unlike a typewriter, the Caps Lock key on a computer keyboard affects only letters. It has no effect on the number or symbol keys. Num Lock & Numeric Keypad Many, but not all, computer keyboards have a numeric keypad usually located on the right side of the keyboard. This keypad has a group of number keys with additional markings like arrows, PgDn, End, etc. The numeric pad is controlled by a toggle key marked Num Lock. When the Num Lock key is on, this pad can be used to enter numbers. When the Num Lock key is off, the functions listed below the number will be activated. 20 Eduheal Foundation Class - 3 & 4
Windows Key The Windows key can be found on some, but not all, keyboards that are used with Windows computers. The Windows key is marked with a small Microsoft Windows symbol and is usually found on the bottom row of the keyboard. There may be two Windows keys, one on each side of the space bar. Pressing the Windows key will bring up the Start menu. Application Key If you have a Windows key on your keyboard, you will also see a key with a design that looks like a list of words on a piece of paper, usually to the left of the space bar. This is called the application key. It is a shortcut for right clicking. It will display an item s shortcut menu. Space Bar The Spacebar is used to insert a blank space. In some programs it can also be used to choose a highlighted item. Backspace Key The Backspace key will remove the character to the left of the cursor. The key is sometimes labeled with only a left-pointing arrow. Tab The Tab key is used to move from field to field and is very useful when filling out forms. Pressing the Shift key and the Tab key simultaneously will usually tab you back to the previous field. Shift Key The Shift key in combination with an alphabetical key will type an upper case letter. The Shift key in combination with one of the number keys on the row above the letter keys or one of the symbol keys will type the symbol that is pictured on the upper part of the key. The Shift key can also be used in conjunction with other keys as a shortcut to a task or can be pressed at a certain time to perform a task. For instance, holding down the Shift key Eduheal Foundation Class - 3& 4 21
while inserting a CD-ROM will skip the auto-run process, allowing you to insert the CD without having it play automatically. Delete Key (Del) Whereas the Backspace key will remove the character to the left of the cursor, the Delete key will remove the key to the right of the cursor. The Delete key can also be used in Windows to remove a highlighted or chosen file or shortcut. Print Screen (PrtScrn) In Windows the Print Screen key sends an image of the screen to the Windows Clipboard instead of the printer. In order to actually print the screen image, you must then paste that image in the Clipboard into a program, like a paint program, and print the screen from that program. Scroll Lock Scroll Lock is a toggle key that changes the effect of the cursor movement keys. In most current programs the Scroll Lock key is disabled and pressing it has no effect. ACTIVITY Fill the correct name of keys in the bubbles: 22 Eduheal Foundation Class - 3 & 4
Exploring Computer Memory Computer Memories How do computer remember all the information loaded into it? Because it has memories. Memory of computer is different from the human memory. Memory of a computer is the place in a computer where we keep data and programs for future use. Computer Memory Primary Memory External Memory Random Access Memory ROM Read Only Memory Random access memory (RAM) is the best known form of computer m em or y. RA M is consid er ed "random access" because you can access any memory cell directly if you know the row and column that intersect at that cell. 1. Stores instructions that are used by the CPU and tells the CPU how to work with the different parts of the computer 2. ROM can also hold programs that are directly accessed by the CPU. One such program is the self-test when the computer is first turned on. The self-test tests to see if all the parts on the main circuit board (mother board) are working correctly 3. The instructions in ROM can not usually be changed. 4. These instructions in ROM are called firmware 5. To change the instructions in ROM you need to usually change the chips or do some other special process that is normally not available to an average user. 6. The instructions in ROM are nonvolatile. i.e. they stay in ROM even when the computer is turned off. Programmable Read-Only Memory Erasable Programmable Read-Only Memory How a Computer Stores Information 1. The computer stores information as a string of zeros (0) and ones (1) The standard string length is eight 0 s or 1 s in a row. Eduheal Foundation Class - 3& 4 23
This standard length is called a byte. 8 Bits = 1 Byte. Bit is the fundamental unit of computer storage. A byte equals one character A character is a letter, number, or symbol - it is about any thing that can be typed on a keyboard. There are 256 standard characters used by almost all computers. Information size measurements. Kilobyte (KB) One kilobyte equals about 1024 bytes. 1 KB is about 140 words, about a half page of typed doublespaced text (words only). Megabyte (MB) One megabyte equals about 1000 KB One megabyte equals about 1,024,000 bytes One megabyte equals about 500 pages of text, or one large book Gigabyte (GB) One gigabyte equals about 1000 MB One gigabyte equals about 1,000,000 KB One gigabyte equals about 1,024,000,000 bytes One gigabyte equals over 1,000 books of text ACTIVITY Why should you use folders? Cross out letters in the grid and write the left over letters to answer the question. Cross out 5 b s Cross out 4 c s Cross out 6 g s Cross out 6 h s Cross out 4 j s Cross out 7 k s Cross out 6 m s Cross out 4 p s Cross out 5 q s Cross out 7 v s Cross out 4 w s Cross out 6 x s Cross out 5 z s 24 Eduheal Foundation Class - 3 & 4
Toolbars In many programs there are rows of buttons called toolbars. You use toolbars to tell the computer what to do. Toolbars have buttons on them so they are quick and easy to use. You can tell what the buttons do by looking at the picture. ACTIVITY 1. Toolbar buttons are computer commands they tell the computer what to do. Use list words to name the buttons below. Undo Open Preview Print New Save P P O S N U 2. Toolbars are a quick way to give the computer a command. Why? Choose (a), (b) or (c). Toolbars are quick to use because: (a) The pictures are pretty colours. (b) It s easy to click a button. (c) I said so. 3. In the toolbars below, draw: A RED circle around PRINT 2 toolbars, A GREEN circle around SAVE 2 toolbars, A YELLOW circle around OPEN 2 toolbars, A BLUE circle around UNDO 1 toolbar. Eduheal Foundation Class - 3& 4 25
4. Here are some toolbar buttons; draw a line to match the button with the command. Bold Delete Cut Open Print Back Save Preview 5. Don t type things more than you need to. Use Copy & Paste to make your work much quicker. Copy and Paste is a bit like using a... Photocopier Internet Pencil 26 Eduheal Foundation Class - 3 & 4
Working With Paintbrush Paint is the programme on which children love to work. You can draw the pictures, edit them and also fill the colours. Let s do a paint activity. Open the Paint program. (Click Start, move over Programs then Accessories, Paint) Locate the toolbar along the left side. Rest your mouse over the buttons on the toolbar to see a pop-up clue appear telling what each tool is. Rest your mouse over this button. What does it say that tool is? In Paint you can use this tool to draw a line. Click once to select the tool. Then drag & drop with your mouse to make the line. Notice these options appear below the toolbar after selecting the LineTool. Here you choose how thick you want your line to be. Click once on a colour for your line. Drag with the left mouse button to draw with the color on the top left. Drag with the right mouse button to use the color on the lower right. Repeat, using the Rectangle Tool and the Ellipse Tool. Try each of the options that appear below the toolbar, and compare the differences. Make your own DOT TO DOT Puzzle: Open the Paint program ACTIVITY Draw a picture outline using simple shapes. Be sure to use the medium size line thickness and make all the lines the same color. Select the circle button and a different color. Make a small dot at each corner of your drawing. Eduheal Foundation Class - 3& 4 27
Select the text button Number each of the dots in order around your picture. Trace around the dots with your finger to make sure you haven t missed any spots. Add interesting details to your picture. Select the fill button and the same colour as your background. Fill each line of your outline so that it disappears. Save your picture and it s ready for someone to try. This is another example you can try. You can make a few changes and have a birdhouse, church, or school. Use your imagination, but remember to keep the outline shape simple. Printing tip: Click Image then Attributes in the menu bar. Set the attributes to 438 width and 600 height to print on one sheet. 28 Eduheal Foundation Class - 3 & 4