Introduction to Computing PDF

Instructional Material For COMP 20013 Introduction to Computing Compiled by: Michael Anjelo O. Miguel, MIT Overview This instructional Material is designed to provide students with a breadth-first overview of computing fundamentals. The materials covered in this course include concepts such as components of the computer system, number system operation and conversion, data representation, digital logic system, levels of programming, computer networks, computer applications, current trends and issues. This course provides and overview of the computing industry and computing profession including research and applications in different fields; an appreciation of computing in different fields such as Biology, Sociology, Environment and Gaming; an understanding of ACM requirements; an appreciation of the history of computing; and knowledge of the key components of computer systems (organization and architecture), malware, computer security, internet and internet protocols, HTML 4/5 and CSS. Course Outcomes 1. Explain fundamental principles, concepts and evolution of computing systems as they relate to different fields. 2. Expound on the recent developments in the different computing knowledge areas 3. Analyze solutions employed by organizations to address different computing issues. 4. Identify and define the components of the computer system. 5. Compare and understand the different number systems such as binary, decimal, and hexadecimal number systems. 6. Perform number conversion, fixed point and floating point number representation. 7. Understand the basics of digital logic system. 8. Identify the different levels of programming. 9. Understand the concepts of data communication, network components, protocols and internet issues. 10. Be aware of the important social issues and the impact that it is having on society. 11. Demonstrate awareness of the important social and ethical issues and computing technologies’ impact on such concerns. 12. Evaluate tools and techniques for purposes of identifying best practices in computing development. Assessment Assessment is the systematic basis for making inferences about the learning and development of students. It is the process of defining, selecting, designing, collecting, analyzing, interpreting, and using information to increase students' learning and development. Herewith, assessment is required at the end of every chapter in this instructional material. Grading System Midterm Grade = 70% Class Standing (Seatwork, Quizzes; Research, Exercises & Projects) + 30% Midterm Examination Finals Grade = 70% Class Standing (Seatwork, Quizzes; Research, Exercises & Projects) + 30% Finals Examination Final Grade = (Midterm Grade + Finals Grade) / 2 Table of Contents Overview of Information and Communications Technology ……………………………….1 Hardware …………………………..….34 Data Representation.……………………………..62 Peopleware...……………………………73 Software …….…..……………………88 Computer Networks …………………………….105 Hypertext Mark-up Language …………………………….135 References …………………………….150 Overview of Information and Communications Technology Learning Outcomes: After successful completion of this lesson, you should be able to:  Categorizes computers.  Contrasts elements of computer system.  Identifies various events/improvements in the computing world.  Qualifies the understanding of computer usage  Illustrate the IPO process  Determine the classifications and generations of computers 1 Overview Twenty first century has been the age of so many technological advancements aimed for making the lives of people better. Technologically advance machines have generated more jobs, a sign that computerization has been making economic impact. Furthermore, this product of technological advancement has always been a major means for creating new physical and human environments. Computer has cut the time needed for calculation enormously. Technology has certainly changed the way of living. It has influenced the different aspects of life and undoubtedly, it plays an important role in the lives of people from every walk of life. Many of the complex and critical processes can be carried out with ease and efficiency with the help of modern technology. Computers are extremely important in the modern world of today. In the fast moving life of the modern world of today, computers hold tremendous significance. Many of us will feel crippled without a computer, as we have gotten so used to this machine. The importance of computers cannot be denied in the corporate or business world, at the work place and even in one's personal life. In the modern work place, pen are paper are becoming extent. It will not be long, before pen and paper stop to exist altogether. Same is the case in schools and colleges. Computer has become an important tool for keeping databases, filing systems, track records. It has made record keeping and account keeping much easier than it ever was. It helps an organization save tons of times. It has made data analysis extremely easy, and it can be done at a single click of the mouse. The emergence of computer-based information has greatly lessened the data processing load of humans. Computers have become a lifeline of all types of businesses, big or small. Computer technology has evolved dramatically over the years and has significantly changed society. As technology advances, it transforms and improves society. Computer-related technology allows for enhancement of social functions previously difficult or impossible to execute. There are great resources available through your computer that can increase your business knowledge, speed up your work output and help you make a positive impression on your colleagues, clients and boss. Elements of Computers A computer is an electronic and programmable machine that accept data (input), process it into useful and meaningful information (output). This conversion of raw data to meaningful information through a process called data processing. Data is manipulated to produce results that will lead to the resolution of a problem or improvement of an existing situation. Similar to a production process, it follows a cycle where inputs (words, numbers, sound and pictures) are fed to a process (computer systems, formula, software and hardware, etc.) to produce output (information, insights and accomplishments). For Example, the user input 50+50 into the computer as data, the computer processes the data and the answer/result is 100 which is information. 2 Input Process Output -Cables -Receives Input -Sound Data -Keyboard -Visual -Processes Data -Microphone -Write disc -Performs Action -Internet -Printer Figure 1-1 Input Process Output Model. First, you enter the data using input such as cables, keyboard, microphone and internet. In the next step of the IPO principle the data entered by the operating system or special software are received and processed. The third and final step of the IPO principle is the output of the data. The output of the data takes place via the common output devices of the computer. This is not necessarily meant that they are printed. Also, the display on your monitor is already as output. Other output devices include speakers and printers. The individual components of IPO must work together to be able to utilize the data processing. There are basically four basic functions of computers - input, storage, processing and output. These are described below: 3 Input. Receiving or accepting information from outside sources. The most common way of performing this function is through the information entered through the keyboard and the click of mouse. Processing. This is really the core of computer operation. The computer processes the data that is fed to the computer by various means and the data already contained in internal memory to produce the results that is the core of all computer application. It is here that raw data is transformed into meaningful information. Central Processing Unit (CPU). Also known as the “Brain and Head of computer” it handles all the instructions user give to the computer, and the faster it does this, the better. The parts of the CPU are:  Arithmetic/Logic Unit (ALU): The ALU is divided into units, an arithmetic unit (AU) and a logic unit (LU).  Arithmetic unit that performs all the mathematical operations, like addition, subtraction, multiplication, division.  Logic unit that performs all the logical operations like testing a value to see if is true or false, and comparative analysis consist of comparisons like less than, greater than, equal to or not etc.  Control Unit: It controls and co-ordinate the overall functioning of the other units of the computer. It controls the flow of data between them during processing taking the instructions stored in the primary storage unit.  Memory Unit: These are special, high-speed storage area within the Central processing unit. The data must be represented in the memory before it can be processed e.g. if two numbers are to be multiplied, both numbers must be in the memory, and the result is also placed in the memory register. This is very fast memory and being on the CPU chip it is close to the ALU. Its purpose it to prevent delays in programs or data arriving from main memory. There are two types of computer memory inside the computer, RAM and ROM.  Random Access Memory (RAM) the computer’s primary working memory which program instructions and data are stored so that they are accessible directly to the central processing unit (CPU). Computer memories therefore, are designed to give the processor random access to the contents 4 Common RAM Chip  Read Only Memory (ROM) –The portion of a computer’s does not lose its contents when you switch off the power and that contains essential system programs that neither you nor the computer can erase. Common ROM chip Output. The result produced by the central processing unit. Raw input data that has been processed by the computer information. The results of the processing are made available for use by any user or other devices. A printout on a sheet of paper that contains information is an example. Storage. The retention of program instructions, initial data, and intermediate data within the computer. So that, this information is available for processing purposes. There are two types of computer storage: primary storage and secondary storage. Primary Storage –also known as the main storage is the area in a computer which data is stored for quick access by computer’s process Secondary Storage –A non-volatile storage medium such as a disk drive that stores program instructions and data, even after you switch off power. Computer Operations There are certain operations that are basic to almost any computer a sound understanding of these basic operations is a necessary prerequisite to examining the specific operations of a particular computer. 5 Timing The activities of the central processor are cyclical. The processor fetches an instruction, performs the operations required, and fetches the next instruction, and so on. This orderly sequence of events requires precise timing, and the CPU therefore requires a free running oscillator clock which furnishes the reference for all processor actions. The combined fetch and execution of a single instruction is referred to as an Instruction Cycle. The portion of a cycle identified with a clearly defined activity is called a State. Instruction Fetch The first state(s) of any instruction cycle will be dedicated to fetching the next instruction. The CPU issues a read signal and the contents of the program counter are sent to memory, which responds by returning the next instruction word. The first byte of the instruction is placed in the instruction register. If the instruction consists of more than one byte, additional states are required to fetch each byte of the instruction. When the entire instruction is present in the CPU, the program counter is incremented (in preparation for the next instruction fetch) and the instruction is decoded. The instruction may call for a memory read or write, an input or output and/or an internal CPU operation, such as a register to register transfer or an add registers operation. Memory Read An instruction fetch is merely a special memory read operation that brings the instruction to the CPU's instruction register. The instruction fetched may then call for data to be read from memory into the CPU. The CPU again issues a read signal and sends the proper memory address; memory responds by returning the requested word. The data received is placed in the accumulator or one of the other general purposes registers (not the instruction register). Memory Write A memory write operation is similar to a read except for the direction of data flow. The CPU issues a write signal, sends the proper memory address, then sends the data word to be written into the addressed memory location. Wait (memory synchronization) The speed of the processing cycle, however, is limited by the memory's Access Time. Once the processor has sent a read address to memory, it cannot proceed until the memory has had time to respond. Most memories are capable of responding much faster than the processing cycle requires. A few, however, cannot supply the addressed byte within the minimum time established by the processor's clock. Therefore a processor should contain a synchronization provision, which permits the memory to request a Wait state. When the memory receives a read or write enable signal, it places a request signal on the processor's READY line, causing the CPU to idle temporarily. After the memory has had time to respond, it frees the processor's READY line, and the instruction cycle proceeds. Input/output Input and Output operations are similar to memory read and write operations with the exception that a peripheral 1/0 device is addressed instead of a memory location. The CPU 6 issues the appropriate input or output control signal, sends the proper device address and either receives the data being input or sends the data to be output. Data can be input/output in either parallel or serial form. All data within a digital computer is represented in binary coded form. A binary data word consists of a group 5 of bits; each bit is either a one or a zero. Parallel 1/0 consists of transferring all bits in the word at the same time, one bit per line. Serial 1/0 consists of transferring one bit at a time on a single line. Naturally serial 1/0 is much slower, but it requires considerably less hardware than does parallel 1/0. Interrupts Interrupt provisions are included on many central processors, as a means of improving the processor's efficiency. Consider the case of a computer that is processing a large volume of data, portions of which are to be output to a printer. The CPU can output a byte of data within a single machine cycle but it may take the printer the equivalent of many machine cycles to actually print the character specified by the data byte. The CPU could then remain idle waiting until the printer can accept the next data byte. If an interrupt capability is implemented on the computer, the CPU can output a data byte then return to data processing. When the printer is ready to accept the next data byte, it can request an interrupt. When the CPU acknowledges the interrupt, it suspends main program execution and automatically branches to a routine that will output the next data byte. After the byte is output, the CPU continues with main program execution. Note that this is, in principle, quite similar to a subroutine call, except that the jump is initiated externally rather than by the program. More complex interrupt structures are possible, in which several interrupting devices share the same processor but have different priority levels. Interruptive processing is an important feature that enables maximum utilization of a processor's capacity for high system throughput. Hold Another important feature that improves the throughput of a processor is the Hold. The hold provision enables Direct Memory Access (DMA) operations. In ordinary input and output operations, the processor itself supervises the entire data transfer. Information to be placed in memory is transferred from the input device to the processor, and then from the processor to the designated memory location. In similar fashion, information that goes from memory to output devices goes by way of the processor. Some peripheral devices, however, are capable of transferring information to and from memory much faster than the processor itself can accomplish the transfer. If any appreciable quantity of data must be transferred to or from such a device, then system throughput will be increased by having the device accomplish the transfer directly. The processor must temporarily suspend its operation during such a transfer, to prevent conflicts that would arise if processor and peripheral device attempted to access memory simultaneously. It is for this reason that a hold provision is included on some processors. 7 Characteristics of Computer Systems The characteristics of computers that have made them so powerful and universally useful are speed, accuracy, diligence, versatility and storage capacity. Let us discuss them briefly. Speed Computers work at an incredible speed, a computer is a very fast device. With speeds reaching up to 50 million operations per second, the computer can process data faster than any other machine designed to perform different tasks. Accuracy Accuracy of a computer is consistently high and the degree of accuracy of a particular computer depends on the instructions and the type of processor. No other system can produce as much accuracy as the computer system. Storage The Computer has an in-built memory where it can store a large amount of data. You can also store data in secondary storage devices such as flash drive, which can be kept outside your computer and can be carried to other computers. The factor that makes computer storage unique is that it can store vast amount of data, but the fact that it can retrieve the information that the user wants in a few seconds. Diligence The computer is a machine, does not suffer from the human traits of tiredness. Nor does it lose concentration even after working continuously for a long time. This characteristic is especially useful for those jobs where same tasks are done again and again. It can perform long and complex calculations with same speed and accuracy from the start till the end. Versatility Computers are very versatile machines. It means the capacity to perform completely different type of work. You may use your computer to prepare payroll slips. Next moment you may use it for inventory management or to prepare electric bills. Advantages and Disadvantages of Computer Today, the computer is used in every field and has made our day to day tasks very easy despite all the merits of computers, they also have their downsides. Read on to learn more about the advantages and disadvantages of a computer. 8 Advantages of Computer  Speed Up Work Efficiency Computer help your work to be a lot easier, much more computing and calculating power than an ordinary human. Computer also helps you communicate with friends, coworkers and other contacts. You can download files through computer that you need in your work.  Fast Communication Computer is the fastest medium of communication rendering postal and chat communication. Moreover, using the internet facilities, your message or any files with small storage size can reach in any part of the world.  Reduction in Paper Work The use of computers for data processing in an organization/company leads to reduction in paper work and speeds up the process. Data in electronic files can be updated, viewed, retrieved and printed as and when required, the problem of maintenance of large number of files gets reduced.  Information Dissemination Computer has web browser, it allows user to access to hundreds upon thousands of websites that provide information for anything and everything. Website with search engines will help you find information quickly.  File Organization Computer organizes your data and information. It automates various tasks that you cannot do manually. Computers can store huge volumes of data; physical files that can fill a whole room can be stored in one computer once they are digitized. Disadvantages of Computer  Cheating Using computers to cheat is a general problem in universities and colleges. Many teachers are very concerned about students cheating in their courses. With the information dissemination capabilities of computer, students tend to use this as their advantage in their education to the extent that they are already cheating.  Technical Problems Computer will always have technical problems/issues that will arise in the latter part of the computer usage. For works or courses that require network access, technical issues can cause major problems. 9  Health risks Too much time in front of monitor may harmfully affect your eyesight. Sitting in front of a computer for too long without exercise can cause a weight gain and other health issues. Computer can have negative effects on your social life and interactions with other people.  Computer Crimes This is one of the most controversial aspects of computer today. Computer can be a tool to different computer crimes. Some people use the computer for negative activities. They use computer to child pornography, cyber terrorism, cyber bullying, etc. Therefore, we can conclude that with the modern technology development, the application of computer technology has become a new trend in recently. Computer technology still has its limitations and weakness. Consequently, when we try to apply computer technology and different software programs to enhance our learning and share it with others, we should realize what the advantages and disadvantages show in current computer technology in order to avoid for misemploying and get its maximum benefits for our learning and the society. Classifications/Categories of Computers Over the years as technology keeps improving, more and more people are using computer as part of their daily lives. Technology has become a significant matter in all our lives. Though some are addicted to it, others only use it once in a while, but still we all have used it at least once. Thankfully we have technology to make our lives easier. Computers are actually all around us, and can be broken down into separate categories depending on their size and processing power. Certain definitions have changed over time with the speedy advances in technology –we have computers that can fit in the palm of our hands now that have as much processing power as a computer that was the size of a whole room half a century ago. Let us take a look at the different types of computers which will help us understand their functions and what they are used for. Personal Computer (PC) A stand-alone computer based on a microprocessor equipped with all the system, utility, application software, and the input/output devices and other peripherals that a user needs to perform one or more tasks. Usually used in home or office setting, also called microcomputer. 10 Desktop Any PC that is designed to fit on a standard-sized desk and equipped with sufficient memory and secondary storage to perform business computing tasks. They usually have more power and storage compared to their movable counterparts. 11 Laptop or Notebook A small portable computer that is light that can be placed/hold on the lap and can be moved around is called laptop. The device can be carry the battery –operated device to classes or meetings conveniently and store any notes or information in it. It integrates the parts of the basic parts of computer (monitor, keyboard, pointing device, CPU, memory and hard drive) in one system/device. Netbook This is similar to a laptop, the only difference being that it is smaller in size, which makes it even more portable. It is also less expensive and performs the basic functions, but its internal parts are not as powerful as a desktop or laptop. 12 Workstation A powerful, single-user computer consists of a more powerful processor, greater memory space and extra ability to perform specific computer instructions and work. Moreover, this computer is commonly used by programmers, game developers, network administrators, video or sound editors and graphic designers/artist. Personal Digital Assistant (PDA) A Personal Digital Assistant is a small, highly integrated computer usually using flash memory for storage instead of a hard drive. It u keyboard. Those which use a digital pen for input are called handheld computers. It is light, portable, has good battery life and fits within your palm, because of which it is also called a palmtop. 13 Server A computer that provides services that received from the users of the network. The server’s main purpose is to provide certain computers. A whole room is necessary to fit the whole server. It has powerful processors and better computer systems. Wearable Computer This device is worn on the body like a watch or visor and is often used by military professionals or doctors to track human actions if their hands are engaged in other activities. Smart watches and fabric PCs are examples of wearable computers. All these types of computers serve a different purpose but there are a few things common in all of them, that is, they help us save time and aid in achieving accuracy in our work. From occupying a whole room to fitting in our pocket, the computer has indeed come a long way. And the best part is that in spite of so many developments and differences in features, its journey has just begun, as the possibilities of what they can do are limitless. 14 Activities/Assessment I. Multiple Choice. Read each question carefully, and then CIRCLE THE ANSWER that best fits the question. 1. It is known as the brain of any computer system. A. ALU B. Memory C. CPU D. Control unit E. None of the above 2. Which part interprets program instructions and initiate control operations? A. Input B. Storage unit C. Logic unit D. Control unit E. None of the above 3. A general purpose single-user microcomputer designed to be operated by one person at a time is? A. Special-purpose computer B. KIPS C. M D. PC E. None of the above 4. This device is worn on the body like a watch or visor and is often used by military professionals or doctors to track human actions if their hands are engaged in other activities. A. Supercomputer B. Desktop C. Mobile phone D. Wearable computer E. None of the above 5. Raw input data that has been processed by the computer information. A. Process B. Input C. Output D. Data E. None of the above II. Identification. Read each statement or question below carefully and fill in the blank(s) with the correct answer. 1. ALU stands for _______________. 2._______________is the computer’s primary working memory in which program instructions and data are stored so that they are accessible directly to the central processing unit 15 (CPU). 3.______________ is similar to a laptop, the only difference being that it is smaller in size, which makes it even more portable. 4.______________ is the part of the computer that holds data and instructions for processing. 5. CPU stands for ______________. III. Application. Read the questions carefully and confine your responses to an analysis of the questions as written. 1. What is a CPU and explain how it works? 2. What are the advantages and disadvantages of computer? 3. What are the classifications/categories of computer? 4. Explain the importance of computers in the government. 5. Explain how the IPO model works? 16 History of Computers "Who invented the computer?" is not a question with a simple answer. The real answer is that many inventors contributed to the history of computers and that a computer is a complex piece of machinery made up of many parts, each of which can be considered a separate invention. In particular, when understanding the history of computer you should look and consider for two things:  The progression in hardware representation of a bit of data: 1. Vacuum Tubes (1950s) - one bit on the size of a thumb; 2. Transistors (1950s and 1960s) - one bit on the size of a fingernail; 3. Integrated Circuits (1960s and 70s) - thousands of bits on the size of a hand 4. Microprocessors (1970s and 2010) - millions of bits on the size of a finger nail. 5. Artificial Intelligence (2010 and on) - billions of bits on the size of a hand.  The progression of the ease of use of computers: 1. Almost impossible to use except by very patient geniuses (inventors, scientists) (1950s); 2. Programmable by highly trained people only (computer professionals, trainers, and rich people)(1960s and 1970s); 3. Useable by just about anyone (kids, students, parents, professionals both technical and non-technical people) (1980s and on). The following brief history of computing is a timeline of how computers evolved from their humble beginnings to the machines of today that surf the Internet, play games and stream multimedia in addition to crunching numbers. ENIAC, 1946 Electronic Numerical Integrator and Computer (ENIAC) was the first electronic general- purpose computer. This was used in World War II for calculation of ballistic trajectories, but not yet completed during that time. However, it was complete a year after the war. 17 SAGE, 1954 Semi-Automatic Ground Environment was a system of large computers designed to help the Air Force track radar data in real time. It also produces a single unified image of the airspace over a wide area. Its enormous computers and huge displays remain a part of cold war lore, and a common prop in some movies. NEAC 2203, 1960 This is a drum-based device manufactured by the Nippon Electric Company (NEC). The NEAC 2203 is among the first transistorized computers. It was used for business, scientific and engineering applications. 18 IBM System/360 IBM System/360 mainframe was the first to cover a complete range of applications, from small to large, from commercial to scientific. System/360 was extremely successful in the market, allowing customers to purchase a smaller system with the knowledge they would always be able to migrate upward if their needs grew, without reprogramming of application software or replacing peripheral devices. Many consider the design one of the most successful computers in history, influencing computer design for years to come. Higher-end System/360 models had roles in NASA's Apollo missions as well as air traffic control systems. 19 CDC 6600, 1964 The Control Data Corporation's 6600 (CDC 6600) is believed to have been the first computer to be designated as a "supercomputer," offering the fastest clock speed for its day (100 nanoseconds).An interactive display console allowed users to view graphical results as data were being processed. The 6600 supported the FORTRAN 66 compiler and a program library. DEC PDP-8, 1965 The 12-bit PDP-8, produced by Digital Equipment Corporation (DEC), is the first successful commercial minicomputer. DEC proposed its own vision, by encouraging users to educate themselves and take part in the evolution of the line. By virtue of their CMOS technology they had low power requirements and were used in some embedded military systems. 20 Interface Message Processor, 1969 The Interface Message Processor provided a system independent interface to the ARPANET that could be used by any computer system, thereby opening the Internet network architecture from the very beginning. The interface message processor (IMP) was the first packet- router. It was part of the ARPANET, the precursor to today's Internet. IMPs monitored network status and gathered statistics. This laid the groundwork for the modern Internet and the network architecture that makes it possible. Kenbak-1, 1971 This computer is often considered as the world's first "personal computer" the Kenbak was touted as an easy-to-use educational tool, but it failed to sell more than several dozen units. Lacking a microprocessor, it had only 256 bytes of computing power and its only output was a series of blinking lights. 21 Cray-1, 1976 The Cray-1 was a supercomputer designed, manufactured and marketed by Cray Research. Featuring a central column surrounded by a padded, circular seat, the Cray-1 looked like no other computer. Apple I, 1976 The original Apple Computer, also known retroactively as the Apple I, or Apple-1, was released by the Apple Computer Company (now Apple Inc.) in 1976. They were designed and hand-built by Steve Wozniak. Wozniak's friend Steve Jobs had the idea of selling the computer. Apple I was initially rejected by his bosses at Hewlett-Packard. Undeterred, he offered it to Silicon Valley's Homebrew Computer Club and, together with his friend Steve Jobs, managed to sell 50 pre-built models to The Byte Shop in Mountain View, California. 22 IBM Personal Computer, 1981 When the IBM Personal Computer (IBM 5150) was introduced to the world 34 years ago, it was dramatically clear to most observers that IBM had done something very new and different. Although IBM's launch of the Personal Computer (IBM 5150) in 1981 set the industry standard for personal computing. IBM had introduced a variety of small computers for individual users several years before that. In short, the introduction of the IBM Personal Computer a quarter-century ago set a worldwide personal computing standard and helped to establish a multibillion-dollar industry. 23 Osborne 1 Portable Computer, 1981 The Osborne 1 was the first commercially successful portable microcomputer, it includes all the components required to be a completely useful and operational computer system:  Two built-in floppy drives which hold 91K of data each, with floppy disk storage compartments  A detachable full-size keyboard with numeric keypad  Built-in, albeit small, monochromes CRT monitor.  Runs the CP/M Operating System, the most popular OS at the time. Hewlett-Packard 150, 1983 Representing the first step in a technology widely available today, The HP-150 was a "compact, powerful and innovative" computer made by Hewlett-Packard in 1983. The HP-150 personal computer featured a touch-sensitive screen that allowed users to activate a feature by touching the screen. The PC had an MS-DOS operating system and an Intel 8088 microprocessor. 24 Deep Blue, 1997 Deep Blue was a chess-playing computer developed by IBM. The game is a collection of challenging problems for minds and machines, but has simple rules, and so is perfect for such experiments. Over the years, many computers took on many chess masters, and the computers lost. IPhone, 2007 The handy little device introduced by Apple CEO Steve Jobs in 2007 not only brings together internet access, a regular cell phone, camera and media player, it supports a wide variety of third party applications, or apps, that supply everything from recipes to maps of the night sky, and wraps it all in a sleek, glossy exterior. 25 iPad, 2010 The iPad is a tablet computer designed and manufactured by Apple. In addition, it's half an inch thick, weighs 1.5 pounds and features a 9.7 inch display. Since the iPad was released in 2010, Apple has sold more than 67 million units of the device. The original iPad was an iPhone gone IMAX and the first successful tablet the world had ever seen. The iPad 2 made it thinner, lighter, and faster. The iPad 3 went Retina and LTE but not comfortably so. The iPad 4 made Retina and LTE sing. And the iPad mini showed portability could be just as important as power. Android TV, 2014 A smart TV platform from Google built around the Android operating system. Users can stream content to your TV via apps, both free and paid, using your internet connection. On that front, it’s the same as Roku and Amazon Fire. You navigate through menus the same way, using your phone as a remote to guide you as you go. Unlike other devices, however, Android has an open system, giving Android TV access to apps Google might not officially approve of. 26 Apple Watch, 2015 Operates primarily in conjunction with the user's iPhone for functions such as configuring the watch, calling and texting, and syncing data with iPhone apps, but can independently connect to a Wi-Fi network for some tasks. Surface Go, 2018 Surface Go is perfect for all your daily tasks, giving you laptop performance, tablet portability, and a stunning touchscreen with the power of Windows 10. Lenovo Yoga 5G, 2020 Lenovo Yoga 5G is a Windows 10 laptop with a 14.00-inch display that has a resolution of 1920x1080 pixels. It is powered by a Snapdragon processor and it comes with 8GB of RAM. 27 I hope you have a better understanding of how the computer developed from giant machinery to something that fits in your hand. The computed development follows a step by step process. It started little by little and from low technology until it became high technology. History and development of computers can change the process of data and information manipulation because and of peoples storage” ’knowledge. Computers continue to develop and upgrade. It can be viewed, collect and handle complicated information. Generations of computers The history of the computer goes back several decades however and there are five definable generations of computers. Each generation is defined by a significant technological development that changes fundamentally how computers operate –leading to more compact, less expensive, but more powerful, efficient and robust machines. The development of electronic computers can be divided into five generations depending upon the technologies used. Each of the five generations of computers is characterized by a major technological development that fundamentally changed the way computers operate. The following are the five generations of computers. First Generation Computers: Vacuum Tubes (1950s) Second Generation Computers: Transistors (1950s and 1960s) Third Generation Computers: Integrated Circuits (1960s and 70s) Fourth Generation Computers: Microprocessors (1970s and 2010) Fifth Generation Computers: Artificial Intelligence (2010 and on) 28 Generation Material Used Description Examples First Generation Vacuum Tubes The first computers used Computers (1950s) vacuum tubes for circuitry and magnetic drums for memory, and were often enormous, taking up entire rooms. They were very expensive to operate and in addition to using a great deal of ENIVAC electricity, generated a lot of heat, which was often the cause of malfunctions. The beginning of commercial computer age is from UNIVAC (Universal Automatic Computer). UNIVAC-1. Table 1.1 First Generation Computers 29 Generation Material Used Description Examples Transistor Second s Transistors replaced vacuum Generation (1950s and tubes and ushered in the Computers 1960s) second generation of Computers. The transistor was invented in 1947 but did not see widespread use in computers until the late 1950s. The transistor was far superior IBM 7094 series to the vacuum tube, allowing computers to become smaller, faster, cheaper, more energy- efficient and more reliable than their first-generation predecessors. Second-generation computers still relied on punched cards for input and printouts for IBM 1400 series output. The size of the computers was decreased by replacing vacuum tubes with transistors. CDC 6600 Table 1.2 Second Generation Computers 30 Generation Material Used Description Examples Third Generation Integrated The development of the Computers Circuits (1960s integrated circuit was the and 70s) hallmark of the third generation of computers. Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed IBM 370 and efficiency of computers. Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system, which allowed the device to IBM System/360 run different. Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors. The computer became smaller in size, faster, more reliable and less expensive. UNIVAC 1108 Table 1.3 Third Generation Computers 31 Generation Material Used Description Examples Fourth Microprocessor The microprocessor brought Generation s (1970s and the fourth generation of Computers 2010) computers, as thousands of integrated circuits were built onto a single silicon chip. What in the first generation filled an entire room could now fit in the palm of the Apple Macintosh hand. As these small computers becam e more 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. It greatly reduced the size of computer. The size of modern Microprocessors is usually one IBM PC square inch. It can contain millions of electronic circuits. Table 1.4 Fourth Generation Computers 32 Generation Material Used Description Examples Fifth Generation Artificial Fifth generation computing Computers Intelligence devices, based on artificial (2010 and on) intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today. The goal of fifth-generation computing is IBM Watson to develop devices that respond to natural language input and are capable of learning and self-organization. Can respond to its surroundings using different types of sensors. Scientists are constantly working to increase the processing power of computers. They are trying to create a computer with real IQ with the help of advanced programming and technologies. Table 1.5 Fifth Generation Computers 33 Computer Hardware Learning Outcomes: After successful completion of this lesson, you should be able to:  Determine the different input, output and storage devices  Distinguish the parts of Motherboard  Explain the basics of digital logic system.  Enumerate the Types of computer Keyboards, mouse, etc.  Familiarized with the parts and functions of Keyboard  Identifies different Hard drive connections 34 Introduction Computer hardware is the collection of physical parts of a computer system. This is also sometime called the machinery or the equipment of the computer. This refers to objects that you can actually touch, like disks, disk drives, display screens, keyboards, printers, boards, chips and many others. A computer's hardware is comprised of many different parts, but perhaps the most important of these is the motherboard. The motherboard is made up of even more parts that power and control the computer. The motherboard brings all the core components together such as the Central Processing Unit (CPU), Memory and Hard Disks. In short, the motherboard connects and allows all of the components in the computer to work together. The main components of computer system are the following:  Motherboard  Input Devices  Output Devices  Storage Devices Figure 2.1 inside the Computer Case Parts 35 Motherboard Motherboard is a printed circuit board that is the foundation of a computer that contains the computer's basic circuitry and components. A motherboard is the physical arrangement in a computer that allow compatible devices to connect to your computer when you need them - devices like digital cameras, printers, etc. Most importantly, the motherboard allows hardware components to communicate with one another. You may also be able to upgrade to a faster PC by replacing the CPU chip. If you were to open up your computer and take out the motherboard, you would probably get pretty confused about all the different parts. Depending on the make and model of your computer, it might look something like the picture below. Input Devices To interact with your computer, you need input devices. An input device for a computer allows you to enter information. The fundamental task of computer input is to move information from the brain of the user into the computer. Examples of input devices include keyboards, mice, scanners, digital cameras and joysticks. However, there are dozens of other devices that can also be used to input data into the 36 computer. Below is the list of some computer input devices that can be used with a computer or a computing device. Keyboard The most frequently used input device for all computers. Moreover, keyboard provides a set of alphabetic, numeric, punctuations, symbols and control keys. When an alphanumeric or punctuation key is pressed, the keyboard sends a coded input signal to the computer, which echoes the signal by displaying a character on-screen. Types of Computer Keyboards  Laptop Keyboards The laptop computer keyboard is a small version of the typical QWERTY keyboard. A typical laptop has the same keyboard type as a normal keyboard, except for the fact that most laptop keyboards condense the symbols into fewer buttons to accommodate less space.  Gaming Keyboards Illuminated keyboards are useful for playing games, during the night, when it's too dark to see the keyboard normally. The multimedia keys are also useful for adjusting the volume, for changing the music tracks and for doing other things, while continually playing your game. 37  Ergonomic Computer Keyboards This computer keyboard designed with ergonomic considerations to minimize muscle strain and a host of related problems.  Laser Keyboards The laser keyboard is a recent gadget to the computing world. This device projects the keyboard on to a flat surface, such as a table or desk. This then allows you to type directly onto the table. However, this invention still needs to be improved and can be frustrating to use at the moment. 38  Wireless Keyboards The main benefits of using a wireless keyboard are that they help to reduce clutter, plus allow you to control your device from a distance. For devices such as the TV that may be a few feet away from where you are sitting, wireless keyboards are as much of a convenience as the remote control. The two main technologies powering wireless keyboards in the market today are: Bluetooth: This is the most popular method of syncing your wireless keyboard to your computer. It works with a range of devices that support Bluetooth, from tablets, some smartphones, to your TV. On the flip side, they aren’t as hassle free to connect as RF keyboards. Radio-frequency (RF): RF keyboards utilize a broadcast technique similar to the Wi-Fi standards to create a wireless connection to your computer. Most keyboards that come with a dongle you insert in the USB port to pair your wireless keyboard with uses 2.4 ghz RF technology. Setting up the connection is painless, though with the dongle RF wireless keyboards are much more limited in the types of devices it works with. The downside of wireless keyboards is that they need to be recharged periodically, though modern wireless keyboards can usually go for months, if not years, between a battery swap. 39 Parts and Functions of Keyboard Character keys The character keys are used for typing text, and in various combinations, as action shortcuts in programs and computer games. These keys include the same letter, number, punctuation, and symbol keys found on a traditional typewriter. It also includes number’s symbols and special key. Modifier keys These keys are used alone or in combination with other keys to perform certain actions. The most frequently used control keys are CTRL, ALT, and SHIFT. These keys are called combination keys because they only work together with other key to perform specific task. Enter and editing keys These keys are used to create new line/paragraph in documents. Moreover, the main function of these keys is to for editing purpose only. System and GUI keys 40 These keys are commonly used in computer program actions. Most of the functions of these keys will create a certain command faster than using your mouse. Aside from it, System and GUI’s keys allows the user of program instructions to go. Navigation keys These keys provide navigation through documents and help you scroll in Web browsers. In addition to this, using these keys will help the user to locate the cursor in documents. Function Keys The function keys are labeled F1 through F12. The functions keys are located at the top of a keyboard and grouped into four. These keys are called function keys because they perform special functions. Numeric keypad Numeric keypad allows you to enter numbers quickly. Numeric keypad compose of numbers from 0 to 9 and symbols like (+, ‐/, and *) belong to this part of the keyboard. It is arranged like a standard calculator used to enter numerical data. Lock keys User has to press a Lock key once to activate it, and you press that Lock key again to deactivate it. When a lock key is on, a corresponding status light will appear in the right side of your keyboard indicating which locks are enabled. Shortcut Keys and their Functions: Some commonly used computer shortcut keys are enumerated below. Shortcut Keys Descriptions Alt + F: File menu options in current program. Alt + E: Edit options in current program. F1: Universal Help in almost every Windows program. Ctrl + A: Select all text. Ctrl + X: Cut selected item Shift + Del: Permanently delete selected item in computer system. Ctrl + C: Copy selected item. Ctrl + Ins: Copy selected item. Ctrl + V: Paste selected item. 41 Shift + Ins: Paste selected item. Home: Goes to beginning of current line. Ctrl + Home: Goes to beginning of document. End: Goes to end of current line. Ctrl + End: Goes to end of document. Shift + Home: Highlights from current position to beginning of line. Shift + End: Highlights from current position to end of line. Ctrl + Left arrow: Moves one word to the left at a time. Ctrl + Right arrow: Moves one word to the right at a time. Ctrl + Alt + Right arrow: Rotate the screen to the right. Ctrl + Alt + Down arrow: Rotate the screen down. Ctrl + Alt + Left arrow: Rotate the screen to the left. Ctrl + Alt + Up arrow: Rotate the screen up or the default screen. Table 2.1 Computer Shortcut Keys and their Functions Mouse An input device, equipped with one or more control buttons that is housed in a palm-sized case and designed so that you can roll the cursor of the mouse. As the mouse moves, its circuits relay signals that correspondingly move a pointer on-screen. The simplest of all mouse functions is repositioning/moving the cursor: you can also use the mouse to trigger an event and choose commands from menus, select text for editing purposes, move objects, and draw pictures on- screen. Two types of Internal Mouse Mechanisms:  Mechanical Mouse This is the traditional/commonly used mouse in the first boost of computer technology in 90’s. This mouse-coated ball on has the underside a rubber of the case. As you move mouse, the ball rotates and optical sensors detect the motion. 42  Optical Mouse This mouse registers its position by detecting reflections from light-emitting diode that directs beam downward. Optical mouse does not need cleaning, because it has no moving parts. This all-electronic feature also eliminates mechanical fatigue and failure. This is an asset in graphics applications, and it makes computer operation easier in general.  Cordless Mouse The mouse relays a signal to a base station wired to the computer's mouse port. The cordless mouse requires power, which comes in the form of batteries. Infrared is much better for precision when moving in small increments when compared to the other types of mouse. 43  Gaming Mouse A desktop mouse with additional functions to make it suited to computer gaming and high intensity programming. These functions often include programmable buttons, higher sensitivity, adjustable weight and faster response times. 44 The tables below shows the defaults for keyboard shortcuts. The current settings for all shortcuts may be found in the Keyboard Options dialogue. Shortcut Keys Descriptions Selects text from where you click and hold to the point you Click, hold, and drag: drag and let go. Double-click: If double-click a word, selects the complete word. Double-click: Double-clicking on the left, center, or right of a blank line will make the alignment of the text left, center, or right aligned. Double-clicking anywhere after text on a line will set a tab Double-click: stop. Selects the line or paragraph of the text the mouse triple- Triple-click: clicked. Ctrl + Mouse wheel: Zooms in and out of document (Shortcut Keys and their Functions). Table 2.2 Mouse Shortcuts Joystick A cursor control device widely used for computer games and software applications. This device is one of the greatest contributions in both computers and gaming. 45 Light pen An input device that uses a light-sensitive stylus to enable you to draw on-screen draws on a graphics tablet or select items from menus. Computer Scanner A peripheral device that digitizes text, photos, and artworks and stores the image as a file you can merge with text in many word processing and page layout programs. 46 Microphone A hardware device that allows computer user to input audio into their computers. Microphone can be used as VoIP, Online Chatting and Voice Recognition. Webcam A webcam is a video camera that feeds or streams its image in real time to or through a computer to computer network. When "captured" by the computer, the video stream may be saved, viewed or sent on to other networks via systems such as the internet, and email as an attachment. Webcam commonly used in video monitoring, video calling, videoconferencing, commerce and video security. 47 Output Devices An output device is any peripheral that receives data from a computer, usually for display, projection, or physical reproduction. Most computer data output that is meant for humans is in the form of audio or video. Thus, most output devices used by humans are in these categories. Examples include monitors, projectors, speakers, headphones and printers. Global Positioning System (GPS) A space-based satellite navigation system that provides location and time information in all weather conditions, anywhere on or near the earth where there is an unobstructed line of sight to four or more GPS satellites. 3 Headphones Headphones originated from the earpiece, and were the only way to listen to electrical audio signals before amplifiers were developed. Headphones may be used with stationary CD and DVD players, home theater, personal computers, or portable devices (e.g. digital audio player/mp3 player, mobile phone, etc.). 48 Monitor Monitor is the piece of computer hardware that displays the video and graphics information generated by the computer through the video card. Monitors are very similar to televisions but usually display information at a much higher resolution. Printer A computer output device designed to print computer-generated text or graphics on paper. Printers are different when it comes to its specifications such as speed, quality, noise, graphics capabilities, weight, built-in fonts, purpose, drivers, and paper usage. 49 Projector Projector also called a digital projection display system is a specialized computer display that projects an enlarged image on a movie screen, projector screen and wall (as long as it compliment to the image projection). Such device is commonly used in presentations. Computer Speakers A hardware device connected to a computer's sound card that outputs sound generated by the computer. Some speakers are designed to work specifically with computers, while others can be hooked up to any type of sound system. Regardless of their design, the purpose of speakers is to produce audio output that can be heard by the listener. 50 Storage Devices A storage device is any computing hardware that is used for storing, porting and extracting data files and objects. The storage device may hold, or save, the information temporarily or permanently. The computer's primary hard drive stores the operating system, applications, and files and folders for users of the computer. They are available in different form factors depending on the type of underlying device. For example, a standard computer has multiple storage devices including RAM, cache, a hard disk, an optical disk drive and externally connected USB drives. Types of computer storage  Magnetic storage devices Magnetic storage is one of the most common types of storage used with computers and is the technology that many computer hard drives use. 51  Optical storage devices Uses lasers and lights as its method of reading and writing data.  Flash memory devices Flash memory has started to replace magnetic media as it becomes cheaper and more efficient solution.  Online and cloud Storing data online and in cloud storage is becoming popular as people need to access their data from more than one device. 52 Hard drive Hard drive is a data storage device used for storing and retrieving digital information. Your Operating System is stored on your hard drive, as well as all your software programs, like Microsoft Word/ Microsoft Offices. What are the different types of hard drive connections? There are four basic ways to connect your hard drive to your computer:  USB USB is the most common connection type for external devices, whether external hard drive, thumb drives, flash drives, printers, cameras, all kinds of other devices. It is extremely easy to use. Whether the computer is powered on or powered off, simply connect the cable to your device and it should be ready to be used less than 30 seconds later (depending on your computer's speed).  FireWire FireWire is a similar connection to USB, in that it is plug-and-play. Simply connect your device to the computer and it will usually be ready to be used within 30 seconds. FireWire is much more common in Mac computers than in Windows computers. 53  Serial ATA (SATA) Serial ATA is the most common connection for internal drives in modern PCs and Macs. There can be multiple SATA ports on any one motherboard or controller card. One cable connects one hard drive to one port on the motherboard (as opposed to Parallel ATA).  eSATA Describe as a less common, high-performance connection most commonly found in PCs. An eSATA connection performs at speeds that most closely resemble an internal drive. eSATA (external Serial ATA) is a high-performance interface most commonly found in Windows PCs, but is fairly rare. 54 Compact Disk (CD) An optical storage device, which data such as music, text, or graphic images is digitally encoded. Compact disks provide read-only secondary storage features which allows only the compute to write and read information from the disk, but cannot change or write new information Jump drive or flash drive A flash drive is a small storage device that can be used to transport files from one computer to another. Flash drives are often referred to as pen drives, thumb drives, or jump drives. USB flash drives have less storage capacity than an external hard drive, but they are smaller and more durable because they do not contain any internal moving parts. 55 Memory card An electronic flash memory storage disk commonly used in consumer electronic devices such as digital cameras, MP3 players, mobile phones, and other small portable devices. There are a handful of different types of memory cards on the market, each varying in size, compatibility, and storage capacity. The most commonly used memory cards are listed below.  CompactFlash (CF) CompactFlash is a flash memory mass storage device used mainly in portable electronic devices. The format was specified and the devices were first manufactured by SanDisk in 1994.  MicroSD MicroSD are the smallest removable flash memory cards, range in available sizes of 128 MB to 4 GB, and often used with cell phones. 56  Multimedia Card/MMC MMC is used as storage media for a portable device, in a form that can easily be removed for access by a PC.. MMC and SD cards differ in their physical size, capacity and their usage. Both come in different memory sizes as well. While MMCs can be used in a standard SD card slot, the latter cannot be used in a MMC slot.  SD Card The SD card is a basic way of transferring information and storing it. The good thing about it is that it’s a non-volatile solution just like the majority of storage devices and you don’t need power source for it to keep the data. 57 Cloud storage Cloud storage means "the storage of data online in the cloud," wherein a company's data is stored in and accessible from multiple distributed and connected resources that comprise a cloud. Cloud storage has several advantages over traditional data storage. Fo example, if you store your data on a cloud storage system, you'll be able to get to that data from any location that has Internet access. Digital Logic System Digital logic is the representation of signals and sequences of a digital circuit through numbers. It is the basis for digital computing and provides a fundamental understanding on how circuits and hardware communicate within a computer. Digital logic is typically embedded into most electronic devices, including calculators, computers, video games, and watches. This field is utilized by many careers that work with computers and technology, such as engineers and repair technicians. A main component of digital logic consists of five different logic gates:  AND  OR  XOR  NAND  NOR These basic logic gates are used in conjunction with one another to build elaborate engineering designs that deliver various computing outcomes. In addition to other types of circuitry and board and chip design, logic gates direct the computing and calculation work that electronic technologies do on a device. For example, circuits use logic gates to construct the outputs for digital numbers on calendars and other displays, by returning separate logical results for each particular digital component or “side” of one of these digital numbers. 58 Simple Digital Logic Gates Simple digital logic gates can be made by combining transistors, diodes and resistors with a simple example of a Diode-Resistor Logic (DRL) AND gate and a Diode-Transistor Logic (DTL) NAND gate given below. The simple 2-input Diode-Resistor AND gate can be converted into a NAND gate by the addition of a single transistor inverting (NOT) stage. Using discrete components such as diodes, resistors and transistors to make digital logic gate circuits are not used in practical commercially available logic IC’s as these circuits suffer from propagation delay or gate delay and also power loss due to the pull-up resistors. Another disadvantage of diode-resistor logic is that there is no “Fan-out” facility which is the ability of a single output to drive many inputs of the next stages. Also this type of design does not turn fully “OFF” as a Logic “0” produces an output voltage of 0.6v (diode voltage drop), so the following TTL and CMOS circuit designs are used instead. 59 Activities/Assessment I. Multiple Choice. Read each question carefully, and then CIRCLE THE ANSWER that best fits the question. 1. The representation of signals and sequences of a digital circuit through numbers. a. Logic gates b. Digital logic c. Circuit d. Frequency e. None of the above 2. Provides read-only secondary storage features which allows only the compute to write and read information from the disk, but cannot change or write new information a. DVD b. Blue-Ray c. CD d. Diskette e. None of the above 3. Any computing hardware that is used for storing, porting and extracting data files and objects. a. Input devices b. Storage devices c. Output devices d. Hard drive e. None of the above 4. This mouse registers its position by detecting reflections from light-emitting diode that directs beam downward. a. Super mouse b. Mouse c. Mechanical mouse d. Optical mouse e. None of the above 5. A hardware device connected to a computer's sound card that outputs sound generated by the computer. a. Microphone b. Printer c. Webcam d. Speaker e. None of the above II. Identification. Read each statement or question below carefully and fill in the blank(s) with the correct answer. 1. _______________ is the collection of physical parts of a computer system. 60 2. _______________ is the most frequently used input device for all computers. 3. _______________ is a video camera that feeds or streams its image in real time to or through a computer to computer network. 4. _______________ is a computer hardware designed with ergonomic considerations to minimize muscle strain and a host of related problems. 5. _______________ these keys are commonly used in computer program actions. III. Application. Read the questions carefully and confine your responses to an analysis of the questions as written. 1. What are the different types of hard drive connections? Explain how it works. 2. Draw and label the parts of keyboard. 61 Data Representation Learning Outcomes: After successful completion of this lesson, you should be able to:  Distinguishes the various number system and data representation  Computes number system operation such addition, subtraction and complement.  Determine different file sizes  Answers/Practices various operations and conversions. 62 Introduction Computers are amazing devices that enable people to do a wide variety of things with them. People can use them to view information, listen to music, play games and more. In order for computers to work, they must represent the information in some way. All data that is stored within a computer, and transferred from or to a computer, is transmitted as a series of electrical signals that are either on or off. To process data, whether it be text, images or sounds, the computer must convert the information into binary form. The binary number system is a base-2 number system. This means it only has two numbers: 0 and 1. All information in a computer (words, pictures, movies and sound) is stored and transmitted as sequences of bits, or binary digits. In Digital Technologies, discrete representation of information using number codes. Data may include characters (for example, alphabetic letters, numbers and symbols), images, sounds and/or instructions that, when represented by number codes, can be manipulated, stored and communicated by digital systems. For example, characters may be represented using ASCII code or images may be represented by a bitmap of numbers representing each 'dot' or pixel. They let you compute and calculate with numerical information; they let you send and receive information over networks. Fundamental to all of this is that the computer has to represent that information in some way inside the computer’s memory, as well as storing it on disk or sending it over a network. A digital system can understand positional number system only where there are a few symbols called digits and these symbols represent different values depending on the position they occupy in the number. A value of each digit in a number can be determined using  The digit  The position of the digit in the number  The base of the number system (where base is defined as the total number of digits available in the number system). Decimal Number System The number system that we use in our day-to-day life is the decimal number system. Decimal number system has base 10 as it uses 10 digits from 0 to 9. In decimal number system, the successive positions to the left of the decimal point represents units, tens, hundreds, thousands and so on. Each position represents a specific power of the base (10). For example, the decimal number 1234 consists of the digit 4 in the units position, 3 in the tens position, 2 in the hundreds position, and 1 in the thousands position, and its value can be written as 63 (1×1000) + (2×100) + (3×10) + (4×l) (1×103) + (2×102) + (3×101) + (4×l00) 1000 + 200 + 30 + 1 1234 As a computer programmer or an IT professional, you should understand the following number systems which are frequently used in computers. Number System Description Binary Number System Base 2. Digits used: 0, 1 Octal Number System Base 8. Digits used: 0 to 7 Decimal number system Ten (10) digits from 0 to 9 Hexa Decimal Number System Base 16. Digits used: 0 to 9, Letters used: A- F Binary Number System A Binary number system has only two digits that are 0 and 1. Every number (value) represents with 0 and 1 in this number system. The base of binary number system is 2, because it has only two digits. Octal Number System Octal number system has only eight (8) digits from 0 to 7. Every number (value) represents with 0,1,2,3,4,5,6 and 7 in this number system. The base of octal number system is 8, because it has only 8 digits. Decimal number system Decimal number system has only ten (10) digits from 0 to 9. Every number (value) represents with 0,1,2,3,4,5,6, 7, 8 and 9 in this number system. The base of decimal number system is 10, because it has only 10 digits. Hexadecimal Number System A Hexadecimal number system has sixteen (16) alphanumeric values from 0 to 9 and A to F. Every number (value) represents with 0,1,2,3,4,5,6, 7, 8, 9, A, B, C, D, E and F in this number system. The base of hexadecimal number system is 16, because it has 16 alphanumeric values. Here A is 10, B is 11, C is 12, D is 13, E is 14 and F is 15. 64 Table of the Numbers Systems with Base, Used Digits, and Examples: Number System Base Use Digits Example Binary 2 0, 1 (11110000)2 Octal 8 0,1,2,3,4,5,6,7 (360)8 Decimal 10 0,1,2,3,4,5,6,7,8,9 (240)10 Hexadecimal 16 0,1,2,3,4,5,6,7,8,9 (F0)16 A,B,C,D,E,F Number System Conversions There are three types of conversion:  Decimal Number System to Other Base [for example: Decimal Number System to Binary Number System]  Other Base to Decimal Number System [for example: Binary Number System to Decimal Number System  Other Base to Other Base [for example: Binary Number System to Hexadecimal Number System] Decimal Number System to Other Base To convert Number system from Decimal Number System to Any Other Base is quite easy; you have to follow just two steps: A) Divide the Number (Decimal Number) by the base of target base system (in which you want to convert the number: Binary (2), octal (8) and Hexadecimal (16)). B) Write the remainder from step 1 as a Least Signification Bit (LSB) to Step last as a Most Significant Bit (MSB). Decimal to Binary Conversion Result Decimal Number is : (12345)10 Binary Number is: 11000000111001 65 Decimal Number is: (13)10 Binary Number is: 1101 Decimal Number is: (29)10 Binary Number is: 11101 Decimal to Octal Conversion Result Decimal Number is: (12345)10 Octal Number is: (30071)8 66 Decimal to Hexadecimal Conversion Result Decimal Number is: (12345)10 Octal Number is: (3039)16 Decimal Number is: (725)10 Hexadecimal Number is: (2D5)16 Convert 10, 11, 12, 13, 14, 15 to its equivalent... A, B, C, D, E, F Other Base System to Decimal Number Base To convert Number System from Any Other Base System to Decimal Number System, you have to follow just three steps: A) Determine the base value of source Number System (that you want to convert), and also determine the position of digits from LSB (first digit’s position – 0, second digit’s position – 1 and so on). B) Multiply each digit with its corresponding multiplication of position value and Base of Source Number System’s Base. C) Add the resulted value in step-B. Explanation regarding examples: Below given exams contains the following rows: A) Row 1 contains the DIGITs of number (that is going to be converted). 67 B) Row 2 contains the POSITION of each digit in the number system. C) Row 3 contains the multiplication: DIGIT* BASE^POSITION. D) Row 4 contains the calculated result of step C. E) And then add each value of step D, resulted value is the Decimal Number. Binary to Decimal Conversion Binary Number is : (11000000111001)2 Octal to Decimal Conversion Octal Number is : (30071)8 =12288+0+0+56+1 =12345 Decimal Number is: (12345)10 Hexadecimal to Decimal Coversion Hexadecimal Number is : (2D5)16 =512+208+5 =725 Decimal Number is: (725)10 Representation of non-numeric data in computer  Representation of alphanumeric data There are 4 types of alphanumeric data: letters, digits, special symbols and control characters. The most common codes to represent alphanumeric data is ASCII code American Standard Code for Information Interchange (ASCII) Each character uses 7 bits e.g. ‘A’ is represented by ‘1000001’ (65 in decimal) ‘a’ is represented by ‘1100001’ (90 in decimal) 68 ‘1’ is represented by ‘0110001’ (49 in decimal) ‘?’ is represented by ‘0111111’ (63 in decimal) Delete is represented by ‘1111111’ (127 in decimal)  Representation of Chinese characters Chinese characters are non-alphanumeric characters There are over ten thousand Chinese characters that are commonly used Since 16 bits can represent 2 16 (65536) patterns, 16 bits (2 bytes) are needed to represent a Chinese character. Common code used to represent traditional Chinese characters is BIG-5 Common codes used to represent simplified Chinese characters is GB (Guobiao), used in Taiwan and HZ (Hanzi) used in Mainland China.  Representation of non-alphanumeric characters Unicode can represent characters of different languages and is accepted globally. It includes Chinese (traditional and simplified), English, French, Japanese, Korean and many others. Understanding the file sizes Memory of a Computer is any physical device which is capable of storing information whether it is large or small and stores it temporarily or permanently. For example, Random Access Memory (RAM), is a type of volatile memory that stores information for a short interval of time, on an integrated circuit used by the operating system. Memory can be either volatile or non-volatile. Volatile memory is a type of memory that loses its contents when the computer or hardware device is switched off. RAM is an example for a volatile memory i.e. why if your computer gets rebooted while working on a program, you lose all the unsaved data. Non-volatile memory, is a memory that keeps its contents saved even in the case of power loss. EPROM ((Erasable Programmable ROM) is an example of a non-volatile memory. Characteristics of Main Memory  Known as the main memory.  Semiconductor memories.  Faster than secondary memories.  A computer cannot run without the primary memory.  It is the working memory of the computer.  Usually volatile memory.  Data is lost in case power is switched off. 69 Units of Memory Unit Shortened Capacity Bit b 1 or 0 (on or off) Byte B 8 bits Kilobyte KB 1024 bytes Megabyte MB 1024 kilobytes Gigabyte GB 1024 megabytes Terabyte TB 1024 gigabytes Petabyte PB 1024 terabytes Exabyte EB 1024 petabytes Zettabyte ZB 1024 exabytes Yottabyte YB 1024 zettabytes Bits are the basic building blocks of not only data storage, but all computers. Computers work in binary digits, combining 0’s and 1’s in countless patterns. These binary digits are known as bits, and are the smallest possible unit for data storage. When 8 bits are combined, you get a byte. Bytes are used to store a single character; whether it’s a letter, number, or punctuation. All memory storage is expressed in terms of bytes, so although bits might be the foundation upon which data storage is built, bytes are the building blocks that truly denote the usability of any one storage solution. Because storage is expressed in terms of bytes, all greater units are typically referred to by their shortened names. This means that you could keep adding more prefixes to talk about more and more data. Above terabyte, we have petabyte (PB), exabyte (EB), zettabyte (ZB), and yottabyte (YB). Once the numbers get high enough, it can be difficult to realistically visualize how much data we’re talking about. This volume of data is really only relevant to tech giants and massive corporations. But as the need for greater storage increases with the volume of data over time, we will inevitably develop the necessary vocabulary. 70 Activities/Assessment I. Application. Read the questions carefully and confine your responses to an analysis of the questions as written. Decimal to Binary Conversion Result Decimal number is: (25673)10 Binary Number is : ______________________ Decimal to Octal Conversion Result Decimal number is: (6260)10 Octal Number is : _____________________ Decimal to Hexadecimal Conversion Result Decimal number is: (1423)10 Hexadecimal Number is : _____________________ 71 Binary to Decimal Conversion Binary number is: (111001)2 Octal to Decimal Conversion Octal number is: (7014)8 Hexadecimal to Decimal Conversion Hexadecimal number is: (E7A9)16 72 Peopleware Learning Outcomes: After successful completion of this lesson, you should be able to:  Different uses of computer in the society  Contrasts roles and job titles in the ICT profession  Invites prospective professional for insights  Organizes forum/discussion with ICT professional 73 Computers in the society There was a time when computers were only heard of as a luxury. However today they are an unavoidable part of success and development. No longer are they owned only through theft and by the filthy rich, in fact computers are and will in the coming days and months be used to accomplish the brilliant goals of success and unparalleled development of the society. Moreover, the computer is being used in every field of life such as medical, business, industry, airline and weather forecasting. Roles of Computer in Health and Medicine Maintaining Record System Managing hospital records reports specific information and issues regarding managing and organizing clinical and non- clinical hospital records. Maintaining records primarily concerned with the inserting, editing, searching and printing of records for the best performance the institution can give when it comes to the Patient Information System information dissemination. 74 Analysis Computerized tomography, more commonly known as a CT or CAT scan, is a diagnostic medical test that, produces multiple images or pictures of the inside of the body. CT images of internal organs, bones, soft tissue and blood vessels typically provide greater detail than traditional x-rays. CT-Scan Radiology X-rays are a type of electromagnetic radiation, just like visible light. An x-ray machine sends individual x-ray particles through the body. The images are recorded on a computer or film. The test is done in a hospital radiology department or in the health care provider's office. X-Ray Roles of Computer in Money and Banking E- Banking Refers to the use of computers to carry out banking transactions such as withdrawals through cash dispensers or transfer of funds at point of sale. This also considered as one of the fastest way of transactions involving money. ATM Machine 75 Mobile Banking Mobile banking has until recently (2010) most often been performed via SMS or the mobile web. Apple's initial success with iPhone and the rapid growth of phones based on Google's Android (operating system) have led to increasing use of special client programs, called apps, downloaded to the mobile device. Mobile w/ Bank Transactions Plastic Money Generic term for all types of bank cards, credit cards, debit cards, smart cards, etc. Plastic money is the new and easier way of paying for goods and services. ATM card Queuing System Queuing is one of the biggest contributions in stores, hospitals, banks and government institutions and a structured approach to queuing is being expected by a large number of customers and citizens. Helps you organize your queues by providing visitors with virtual and linear Counting System Monitor queuing solutions and booked appointments. 76 Roles of Computer in Law Enforcement Databases The shift from performing tasks manually to placing the strain on IT systems in law enforcement continues to advance. Whether it is the introduction of informational websites for the authority, it is clear that technology is playing an ever increasing role in a range of authority. Police Information System Sharing Information Information sharing can often take place without your consent. In many cases where you are not asked your permission, the information sharing will be reasonable and expected. However, it should be clear why the information is being shared and who is involved. Law Enforcement Website Crime Scene Computing Forensic reconstruction is essentially the process of establishing a sequence of events about the occurrences during and after a crime or other incident through the study, analysis and interpretation of evidence. It may not be known exactly what has occurred due to lack of evidence or witnesses but reconstructing the crime Auto-CAD of Crime Scene scene will help in solving the case.

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