Computer Generation PDF

1.1. Computer Generation Brainstorming activity Do you know the evolution of computer? The term generation refers to the period of development of the computers. Computer generation is change happened in the development of computers. The evolution of computer is divided into generations. Each generat...

1.1. Computer Generation Brainstorming activity Do you know the evolution of computer? The term generation refers to the period of development of the computers. Computer generation is change happened in the development of computers. The evolution of computer is divided into generations. Each generation is characterized by a major technological development that changed the way computers operate. Initially, the term generation was used to distinguish hardware technologies. Nowadays, generation includes the changes in hardware and software. There are five computer generations. These are: A. First generation B. Second generation C. Third generation D. Fourth generation E. Fifth generation 1.1.1. The First Generation (1940-1956) The earliest generation of computer is the first generation. The first generation of computer used a vacuum tube for electric circuit. The vacuum tube was a basic component of the first generations of computer. Figure 1.1. The First Generation of Computer The first generation of computers used vacuum tube as a core of technology, as shown in Figure 1.2 below. The first generation was large and very expensive computer, as shown in Figure 1.1. It needs high power of electricity and generates a lot of heat.kkkkkkkkkkkkkkkkk Information Technology Student’s Textbook 2 3 Figure 1.2. Vacuum Tube 1.1.2. The Second Generation (1956-1963) The second generation of computer used transistor as the basic component. The transistor, as shown in Figure 1.4 below, was invented in 1947 but was not seen widely spread to be used in computers until the late 1950s. Figure 1.3. The Second Generation of Computer Figure 1.4 Transistors 1.1.3. The Third Generation (1964-1971) The third generation of computer is a computer that emerged due to the development of the integrated circuit (IC). ※ Vacuum tube is an electronic device that controls the flow of electrons in a vacuum.kkkkkkk ※ Transistor is an electronic device used to control the flow of electricity in electronic equipment. kkkkkkkkkkkkkk Unit 1: Basics of Computer Grade 8 4 The development of the IC was the characteristic of the third generation of computers. kkkkkk Figure 1.5. The Third Generation of Computer An IC refers to a small electronic device developed from semiconductor materials. An integrated circuit is the core of technology that is used in the third generation of computer, as shown in Figure 1.6 below. Figure 1.6. Integrated Circuit 1.1.4. The Fourth Generation (1971-Present) The fourth generation of computer is the progressive version of the third generation of computer, as shown in Figure 1.7 below. Figure 1.7. The Fourth Generation of Computer The fourth generation of computer is suitable to have in the palm of the ※ Integrated circuit is an integrated system of multiple, small and interconnected components.kkkkkkkkkkkkk The fourth generation of computer used very large scale integrated (VLSI) circuit. VLSI is the current level of computer microchip containing hundreds of thousands of transistors. It is more powerful, compact sized, reliable, and affordable generation of computer. Information Technology Student’s Textbook 4 5 hand. As a result, it gave rise to the revolution of Personal Computer (PC). Figure 1.8. Microprocessor 1.1.5. The Fifth Generation (Present and Beyond) The fifth-generation of computer uses Artificial Intelligence (AI) applications such as robotics, game playing and natural language processing. The goal of the fifth generation of computer is to create machines that can learn and organize themselves. The development of the fifth generation of computer is intended to solve complex problems. The fifth- generation of computer has the ability to perform parallel data processing; which helps to develop AI applications. The parallel processing is used to enable the computer to achieve simultaneous data processing tasks to increase the mathematical calculation speed of a computer system. The parallel processing system can carry out simultaneous data processing to achieve a faster execution time. The primary purpose of parallel processing is to enhance the computer processing capability and increase the amount of processing accomplished at a given time interval. Figure 1.9. Example of the Fifth Generation of Computer ※ Very large scale integrated circuit is the current level of computer microchip containing hundreds of thousands of transistors.kkkkkkkkkkkkkkkkk ※ Artificial intelligence refers to the simulation of human intelligence in machines that are programmed to think like humans and mimic their actions. Unit 1: Basics of Computer Grade 8 6 1.2. Functions of Computer There are four basic functions of computer. These are: Input Process Output Storage 1.2.1. Input Input is a process of inserting data into a computer. A computer takes data from the user in order to process and store it. For example, to find the product of numbers, the computer first takes the numbers as an input from a user. The data can be entered into computer maybe by typing from keyboard, taking picture, using cameras and recording audios. 1.2.2. Processing Processing is making some operations on the entered data. For example, a computer can take two numbers and calculate their sum. You can also take photo editing as an example. You can make change in colors, borders and brightness of your photo to make it more beautiful. Moreover, you can see your roster preparation. Computer can take the students’ marks as input and calculate the average, select top students as well as total marks. 1.2.3. Output Output is displaying the result obtained from processing to the users. The output can be displayed through monitor, speaker and printer. Activity 1.1 Discuss the time range of inventions and key differences between generations of computer in groups. Information Technology Student’s Textbook How do you associate the functions of computer in processing data with that of human mind? Brainstorming activity 6 7 For example, the printer can print the output of roster processing on paper. 1.2.4. Storage Computer is used to store data. The storage can be a computer’s internal or external storage. Storage usually occurs on a hard drive, flash drive, and a compact disk (CD). For example, you can save your photo on your mobile memory, videos on CD, and your roster on computer hard drive. The four basic functions of computer are presented in the Figure 1.10 below. Figure 1.10 Functions of computer Activity 1.2 Discuss how computer works in a group? 1.3. Types of Computer Brainstorming activity Do you know the types of computer? Computers can be classified based on their size, storage, speed, methods of operation, and purpose of application. I. Types of computer by their size, storage and speed Based on their size, storage, speed there are four types of computer: Microcomputer Minicomputer Mainframe computer Supercomputer Unit 1: Basics of Computer Grade 8 8 1. Microcomputer Microcomputer is a small sized computer used for general purpose. Microcomputers are the most widely used type of computers. They are small and fit on desktops, have varying capacity and easy to handle. Microcomputers are referred to as Personal Computers (PC). They have video display unit for output purpose. Data can be entered through the keyboard and stored on different storage devices such as removable disk, compact Disk (CD) and external hard disk. Personal computers (PCs) are the popular form of such computers used by different individuals as well as organizations. The PCs are classified as: A. Desktops: These are the computers whose case sits on a desk with its keyboard in front of it and its monitor often on top, as show in Figure 1.11 A. There are also desktop computers, which do not have separate system unit and monitor. Both sys tem unit and monitor are integrated in one device, as shown in Figure 1.11 B below. B. Portables: These PCs are so small that they can be placed in a handbag. The difference between portables and desktops is that portables can be carried while traveling unlike desktops. The portables are also classified as: Figure 1.11: A. Desktop with a system unit and monitor B. Desktop with IntegratedSystem unit and Monitor Information Technology Student’s Textbook 8 9 i. Laptops: These small sized computers having the same power as a desktop. they are small enough to carry and designed for use outside an office, as shown in Figure 1.12. kkkkkkkkkkkkkkkkk Figure 1.12: Laptop Figure 1.13: Notebook Figure 1.14: Tablet ii. Notebooks: These are smaller than a laptop and designed to overcome the drawbacks of a laptop. They have the size of a notebook but they are as powerful as a desktop, as shown in Figure 1.13.kkkkkkkkkkkkkkhhhhhhhh iii. Tablet: is a portable personal computer with a touch screen. A tablet is typically smaller than a notebook computer, but larger than a smartphone. A smartphone is a portable device that combines mobile telephone and computing functions into one unit. The touch screen display operates bya finger instead of the mouse, touchpad, and keyboard of larger computers, as shown in Figure 1.14.kkkkkkkkkkkkkkkkkkkkkk B. Desktop with IntegratedSystem unit and Monitor Unit 1: Basics of Computer Grade 8 10 2. Minicomputer Figure 1.15: Minicomputer 3. Mainframe Computer Mainframe computers are large and powerful computers that are physically larger than microcomputer and minicomputer. Figure 1.16: Mainframe Computer Minicomputers are larger and more powerful than most microcomputers, but smaller and less powerful than mainframe computers. They are small and general-purpose computers. These computers have processors with faster instruction processing speeds. Mainframe computers process data at very high rates of speed, measured in millions of instructions per second. Mainframes are designed for many users and can be used at a time and process vast amounts of data quickly. For example, banks, insurance companies, manufacturers, and airlines are typical users of these computers. Information Technology Student’s Textbook 10 11 4. Supercomputer Supercomputer is a high-speed processing computer. A supercomputer is characterized by fastest speed, and most powerful capacity. This computer is capable of processing trillions of instructions per second. Supercomputers are largely used by research organizations, military defense systems, national weather forecasting agencies, large corpo rations, and aircraft manufacturers. Figure 1.17: Supercomputer II. Types of computer based on their methods of operation Based on methods of operation, this category of computers has three types: 1. Analog Computer 2. Digital Computer and 3. Hybrid Computer Unit 1: Basics of Computer Grade 8 12 A.Analog Computer Analog computer is a type of computer that was used to process continuous data. Analog computer was used in the 1950s and 1960s. It has limited memory and store less amount of data. It works with continuous data rather than discrete values. For example, analog computers used to process continuous values such as speed, temperature, pressure and current. Analog computers directly accept the data from the measuring device without first converting it into numbers and codes. They measure the continuous changes in physical quantity and generally provide output as a reading on a dial or scale. Speedometer and mercury thermometer are examples of analog computers.vvvvvvvvvvvvvvfvv Figure 1.18: Analog Computer (Heartrate Monitor Machine) B. Digital Computer Digital computer was designed to perform calculations and logical operations at high speed. Digital computers transmit the data on a discrete value. It accepts the raw data as an input in the form of digits and processes it with programs stored in its memory to produce the output. Figure 1.19: Digital Computer Information Technology Student’s Textbook 12 13 C. Hybrid Computer Figure 1.20: Hybrid Computer III. Types of computer based on their purpose of application Computers can be used for different purposes. Based on their application, they are classified as special purpose or general-purpose computers. A. Special Purpose Computers Special purpose computers are designed to solve a single problem. Their components and their functions are uniquely adapted to a specific situation involving a specific application. Examples: The public telephone box Road Traffic control and safety system Ticket machines (for example in grocery and super market.) Pocket-calculators and Counters. Hybrid computer has characteristics of both analog and digital computer. It is fast like analog computer and accurate like digital computers. It can process both continuous and discrete data. It accepts analog signals and converts them into digital form before processing. So, it is widely used in specialized applications where both analog and digital data is processed. A processor used in a petrol pump that converts the measurements of fuel flow into quantity and price is an example of hybrid computer. Similarly , it is also used in airplanes, hospitals, and scientific applications.jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj Unit 1: Basics of Computer Grade 8 14 B. General Purpose Computers General-purpose computers are designed to solve a variety of problems. They are programs or set of instructions designed to solve a problem. General-purpose computers are more flexible and versatile. Examples include: Microcomputers Minicomputers Supercomputers. Activity 1.3 Form a group and discuss the differences between ana log computer and digital computer based on the data they operate. 1.4. Characteristics of Computers Brainstorming activity What are the major characteristics of computer? Characteristics of computer indicate the qualities, limitations and features of a computer. There are various characteristics of computer depending on their size, capacity, and specifications. Major characteristics of computer are: Speed: A computer works very fast and at high speed while performing mathematical calculations as compared to hu mans. For example, to perform mathematical calculations, the computers can process millions of instructions per sec ond. The time taken by computers for their operations is mi croseconds and nanoseconds. Accuracy: Computers perform calculations with 100% accu Information Technology Student’s Textbook 14 15 racy. Errors may occur due to data inconsistency or inaccuracy. Diligence: A computer is free from tiredness. It does not feel any fatigue or lack of concentration. Versatility: refers to the capability of a computer to perform different kinds of works with same accuracy and efficiency. Reliability: A computer is reliable as it gives consistent result for similar set of data. Automatic: Computer performs all the tasks automatically i.e., it performs tasks without manual intervention. Power of remembering: Computer has the power of storing any amount of information or data. Any information can be stored and remembered as long as you require it, for a long period. No IQ: Computer cannot do any work without instruction from the user. Thus, it does not have IQ (Intelligence Quatient). No Feeling: Computer does not get tired even after long hours of work. Computer does not have a feeling or emotion, taste, knowledge and experience. Storage: Computer has a capacity to store a large amount of data. The Computer has an in-built memory where it can store a large amount of data. ※ No Intelligence Quatient (IQ): Computers cannot work by their own unless a set of instructions are given to it. ※ No Feeling: Computer does not have feelings and emotions. Although it has memory, it cannot work like a human brain. Unit 1: Basics of Computer Grade 8 16 Information Technology Student’s Textbook Summary In this unit, you have learnt about generations, functions, types and characteristics of computers. The following points are summary of this unit. Computer is an electronic device, which accepts instructions in order to perform certain tasks. The evolution of computer is defined in terms of the five generations of computer. Each generation of computer is categorized based on a new technological development, low price and small size, more powerful operation, fast speed and functionality. A smartphone is a portable device that combines mobile telephone and computing functions into one unit. There are four basic computer functions: accepting input, processing, providing output and storing data. Computers can be classified based on: size, methods of operation and purpose of application. Types of computer based on size are microcomputer, minicomputer, mainframe computer and super computer. Types of computer based on method of operation are analog, digital and hybrid computer. Types of computer based on purpose of application are special purpose and general-purpose computer. Characteristics of computer are speed, accuracy, diligence, versatility, reliability, automation, power of remembering, no IQ and capacity to store more data. 16 17 Review Questions Part I: Say “True” if the statement is correct and “False” if it is incorrect. 1. A supercomputer is the fastest, most powerful, and most expen sive type of computer. 2. The computers that used transistors are called the First Genera tion Computers. 3. The third generation computers used integrated circuits. 4. Personal computers are also called microcomputers. 5. Computers provide a perfect and accurate result even when wrong data is entered. Part II: For each of the following questions choose the correct answer. 1. The acronym PC stands for: A. Private Computer B. Personal Computer C. Personal Compact D. All 2. Which one is the most powerful type of computer? A. Minicomputer B. Microcomputer C. Mainframe computer D. Supercomputer 3. _____________ is the way a computer accepts data from the user a A. Input B. Process C. Output D. Storage 4. Which one is not a characteristic of computer? A. Versatility B. Reliability C. Analog D. Storage 5. Computers are designed to solve a single problem. A. General purpose B. Supercomputer C. Special purpose D. All Unit 1: Basics of Computer Grade 8 18 Part III: Match column “A” with their corresponding description stated under column “B”. A B 1. Artificial Intelligence 2. Integrated Circuits 3. Vacuum Tubes 4. Transistors 5. Microprocessors Part IV: Read the statements and fill the blank space. 1. The evolution of computers is mainly divided into ____________ main generations. 2. Each new generation of computers resulted in decrease in ______ and __________. 3. The computers that used ________ were called the first genera tion computers. 4. ______ computer generation will have the power to learn and apply knowledge to solve a problem. 5. ______ has characteristics of both analog and digital computers. A. First Generation B. Second Generation C. Third Generation D. Fourth Generation E. Fifth Generation Information Technology Student’s Textbook 19 19 Overview In this unit, you will learn about hardware categories based on information processing such as input, output, storage and processing devices and their functions. Computer system is composed of computer hardware and software. Computer hardware is the physical part of a computer that we can see by our naked eyes and touch by our hand. It is divided into four categories based on information processing; input, processor, storage and output devices. Brainstorming activity Do you recall the components of computer hardware that you learned in Grade 7? At the end of this unit, students will be able to : explain hardware components of computer; identify input, output, storages and processing devices ; explain functions of input, output, storages devices processing. UNIT Computer Hardware Unit Outcomes 2 Unit 2: Computer Hardware Grade 8 20 2.1. Input Devices Brainstorming activity Before we start our lesson today, can you list input devices? And discuss what is the function of each devices?KKKKKKKKKKKKKKKKKKKKKKK Input devices are computer hardware that are used to enter a data to the computer. they convert the data into the form that can be understandable by a computer as 0 and 1. The following are some of input devices: Keyboard Mouse Scanner Optical Recognition Systems Optical Speech Recognition Joystick Light Pen Touch Screen A. Keyboard Keyboard is an input device which has keys that enable one to enter data into a computer. Figure 2.1: Keyboard The keys on the keyboard can be divided into several groups based on their function as follows. Information Technology Student’s Textbook 20 21 1. Escape Key (ESC): Esc is a key found on the top-left corner of a computer keyboard. It allows the user to cancel, or close an oper ation. 2. Backspace Key: The back space key is a keyboard key that deletes any character before the cursor›s current position. 3. Function keys: The function keys are used to perform specific tasks, for instance F1 is mostly used as the help key. 4. Navigation and Editing Keys: These keys are used for moving around in the documents. They include the arrow keys, Home, End, Page Up, Page Down, Delete, and Insert buttons. 5. Typing (alphanumeric) keys: These keys include letters, num bers, punctuation marks, and symbol keys found on a traditional typewriter. 6. CTRL Key: These keys are used alone or in combination with other keys to perform such tasks as bold, italic, underline, save, copy, cut and paste. 7. Windows Key: Most keyboards have the Windows key near the Ctrl key. If you tap the Windows key, it opens the Start Menu. Then press the Windows key again to close the Start Menu. In addition Windows key with others keys perform different activi ties, for example, Windows logo key plus D display the desktop, Windows logo key plus E open computer and Windows logo key plus L lock your computer or switch users. 8. ALT Key: The alternate key provides alternate input and opera tions when pressed in combination with other keys. 9. Directional Keys: There are four keys on a computer keyboard with arrows up, down, left, and right. 10.Numeric Keypad: The numeric keypad is used for entering numbers quickly. The keys are grouped together in a block like calculator or adding machine. Unit 2: Computer Hardware Grade 8 22 Figure 2.2: Parts of Keyboard B. Mouse Mouse is a hand operating device which controls the movement of the cursor or pointer. Its name is derived from its shape, which looks like a bit a mouse. The mouse are commonly has three buttons. 1. Left-button: used for left click. e.g. to select text 2. Right-button: used for right click. e.g. to see the property of the file 3. Middle button: used for scrolling purpose. This button is some times missing. Figure 2.3: The mouse buttons Information Technology Student’s Textbook 22 23 Mouses are connected to the system unit by a cable (wire) or by wireless. The wireless is also called cordless mouse or wireless mouse. The mouse pad is a pad on which you can move a mouse. C. Scanner Scanner is an input device that accepts printed text, handwriting or an object and converts it to a digital document. It is used to input data directly into the computer from the source document without copying and typing the data. The input data to be scanned can be a picture, a text or a mark on a paper. Figure 2.4: Scanner D.Optical Recognition Systems (ORS) ORS uses light to read characters, codes, and marks. It converts them into a computer understandable format 0 and 1. There are many types of optical recognition systems. 1. Optical Character Recognition 2. Optical Mark Recognition 3. Barcode Reader 1. Optical Character Recognition (OCR) OCR device is a scanner that reads typewritten, computer printed, and in some cases hand written characters from ordinary documents. It scans the shape of the characters and compares it with predefined font shapes found in memory. It can convert the characters into computer code comparison. It is used to enter documents found on paper into computer without the need to type it using a keyboard. Unit 2: Computer Hardware Grade 8 24 Figure 2.5: Optical Character Recognition 2. Optical Mark Recognition (OMR) OMR device senses the presence or absence of a mark such as pencil marks. Itdoes not identify letters of the alphabet, instead, it uses electronic scanners, marks and symbols. It converts marks and symbols into appropriate electronic signals. OMR is used to correct exams. The read mark is interpreted and matched against previously entered answer key. For example, Ethiopian School Leaving Certificate Examination (ESLCE) is corrected using this device. Figure 2.6: Optical Mark Recognition (OMR