INTRODUCTION TO COMPUTER HARDWARE PDF

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RESTRICTED INTRODUCTION TO COMPUTER HARDWARE CHAPTER ONE INTRODUCTION DEFINITION OF COMPUTER. What Is a Computer? A Computer is an electronic device, operating under the control of instructions stored in its own memory, that can accept data, process the data according to specified rules, produce res...

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INTRODUCTION TO COMPUTER HARDWARE CHAPTER ONE INTRODUCTION DEFINITION OF COMPUTER. What Is a Computer? A Computer is an electronic device, operating under the control of instructions stored in its own memory, that can accept data, process the data according to specified rules, produce results, and stores the results for future use. In other words, a computer can generally be defined as an electronic device that does computation and makes logical decisions according to instructions and data that have been gi e to it. Thus the phrase gar age-in-garbage-out. Data and Information Computers process data into information. Data can be defined as a collection of unprocessed items or files, which can take the form of; text, numbers, images, audio, and video. Information can also be defined as processed or refined data items which conveys meaning and is useful to people. Many daily activities either involve the use of or depend on information from a computer. Information Processing Cycle Computers process data (input) into information (output). Computers carry out processes using instructions, which are the steps that tell the computer how to perform a particular task. A collection of related instructions organized for a common purpose is referred to as Software. A computer often holds data, information, and instructions in storage for future use. Some people refer to the series of input, process, output, and storage activities as the Information Processing Cycle. INPUT

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Most computers today communicate with other computers. As a result, communications also has become an essential element of the information processing cycle.

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CHARACTERISTICS OF COMPUTER. SPEED: The computer can process information many thousand times faster than the human brain. What could take a man some hours to accomplish may take a computer a few seconds. ACCURACY: The probability of error from a slim, in most cases, errors output are a result of input by the computer or programmer. Thus the saying gar age in garbage out DURABILITY: The computer lasts more than lifetime. Computers designed and built in the 80s are still functioning today. AUTOMATIC: Human supervision is usually required for a lot of work process. The computer does not require human supervision to function. VERSATILITY: The use of computer is no longer limited to educationists and military operations. Every imaginable profession and business now uses it. LIMITATIONS: The Computer has some very serious limitations. It is incapable of thought, lacks initiative and cannot react to unforeseen (unprogrammed) events. With the right criteria. It will carry out a deadly function accurately. Where it should produce incremental results and input data has error, the subsequent incremental output will be hugely erroneous and may have fatal consequence.

COMPUTER CLASSIFICATION. Classification Based on SIZE: a. Main-frame or Super computer: This is the biggest in both size and capacity. It supports many users at a time, committed via a terminal monitor and keyboard. It is very expensive and consumes electric power. b. Mini-computer: This is bigger than the micro –computer and it supports ore tha o e user. It s a it e pe si e a d used ostl i o puters. c. Micro-computer: This computer is the smallest in size it has a very high speed and consumes less electric power, it s made up of micro-chips and it is a less expensive micro-computer support single use e.g. (PC or Desktop computer).

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Classification Based On GENERATION: The classification is based on the evolution of electrical or electronic computers. These would further classify digital computers into. a. First Generation Computers: They are made of electrical switches, vacuum tubes and valves. These components were bulky and tended to make the computers large and heavy. The components generated lots of heat and therefore required special cooling systems. b. Second Generation Computers: They are made from electronic switches called transistors. Transistors are semi-conductor devices that generate less heat, lasted longer and are much smaller and lighter. c. Third Generation Computers: They are made of integrated circuit (IC). IC s are o pa t tra sistors pla ed o a ti sli e of sili o ater. This de i e gave better performance to the computer and greatly reduced the size of the computer. d. Fourth Generation Computers: These are made from greatly enhanced integrated circuits. They are the ones in use today. e. Fifth Generation Computers: These are the computers of the future. They will have artificial intelligence (AI). Classification Based on TYPES: a. Analogue Computer: It is a computer, which operates on continuous data (data obtained by measurement), usually of a physical quantities such as electrical potential, fluid pressures or mechanical motion. Analogue computer is usually a special purpose computer dedicated to a single task. b. Digital Computer: Is a computer, which operates on discrete data (obtained by counting), by manipulating combinations of binary digits it can perform mathematical calculations, organise and analyse data, control industrial and other processes and simulate dynamic system. c. Hybrid computer: This is a computer that combines the feature of both Analogue and digital computer and is referred to as Anatel.

EVOLUTION OF COMPUTER. The historical development of the computer can be associated with human activities such as calculating, counting and so on. All efforts, which are made RESTRICTED

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to simplify the method of calculation in the past, could be interpreted as attempts at computing. For instance in simple arithmetic, the use of Four Figure Table and Slide Rule are different ways of making calculation easy. It is the quest for way of making improving the method of calculation that led to the invention of Abacus, which is the first machine of that sort. The name Abacus is derived from the Greek word abax, hi h ea s, oard or al ulati g ta le . The A a us as pro a l i e ted a ie t “u eria s i Mesopotamia before the Hindu-Arabic numeration system became popular. The Abacus was used for counting, adding and subtracting. In a way, it was a mechanical system for counting, consisting of strings and moving beads. This remained the fastest calculating device until 1642 when a French Scientist Blaise Pascal invented another calculating device which use of wheel and cogs. The history of computer can be traced back to the 19 th century. When an English inventor Charles Babbage in 1830 developed plans for analytical engine capable of performing arithmetical operations on the basis of instructions from punch card. The analytical engine has – a memory unit to which numbers can be stored: A Control Unit. An Input Unit. An Output Unit and most of other basis element of the present day-computer. Then later in the 20th century, the modern computers came into the development, and their generations are characterised by their technology: a. The First generation computers are the first electronic computers a d ere de eloped the use of a uu Tu e as s it hes, hi h are used to represent as well control the routing of data (binary digits). Although the tubes worked, they had many problems, as high power consumption and heat generation. They were developed mostly in US after World War II. b. The second generation was introduced somewhere in 1960, used transistor which make them faster, more efficient and consume less RESTRICTED

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power. The second-generation computers were the first successful commercial computers. c. The third generation computers came in the late 1960s and 1970 were characterised by miniaturisation of components and use integrated circuits (I.C) and Very Large Scale Integrated Circuits (VLSIC), which contain millions of integrated transistors. d. The fourth generation Computers are defined by the introduction of the microprocessor in 1974. The first personal computer falls into this category named IBM 5100. e. The fifth generation computers emphasize on the intensive software development, where Artificial Intelligence is put into use focusing on machine reasoning and logic programming languages. This is yet to be operational.

USES OF COMPUTER. The uses of computer can never be over emphasised simple because they are now used in every part of human endeavour. Some of these aspects are: a. As an Office Assistance: This includes the use of computer in wordprocessing, spread sheet and other utilities. b. In Communications: This includes mobile telephone networks, communicating with satellite c. In Entertainment: This includes graphics in movie making, computerised Audio/visual gadgets and media presentation. d. In Education: This includes, helping students in solving complex problems, easy reference and sources of information. e. In Game Playing: This includes Videogames, Chess Playing. f. In Business: Through Internet and Networks, e-commence and eBusiness are in operation, baking online, Shopping on-the net. g. In Remote Sensing: This Includes survey and weather forecasting etc.

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APPLICATION OF COMPUTER. IN MILITARY. In military researches: These involve both the research on the development of complex systems, networks, weapons and others for the successful running of the military: a. In weapon control and launching b. In controlling unman planes. c. In navigation and locating of positions by the use of GPS fire control system. IN MEDICINE. Computer is used in the medical centre for: a. Patient diagnosis: This is achieved by the help of medical expert systems b. For analysing the result of test such as ECG scanning in the medical laboratory. c. For keeping patients database: for record retrieving purposes. d. As operation aids. e. In drug monitoring and inventory keeping. IN INDUSTRY. Computer is used in the industries for the following: a. In control rooms: For monitoring of production machineries and their control. b. Computer integrated manufacturing: Data-driven automation that affects all system within a manufacturing environment design and development, production, marketing and sales, and support and service. c. Basic manufacturing functions as well as materials: Handling and inventory control can also be simulated by computer (CIM) before the system is built in an attempt to eliminate wastage. d. In production forecasting: By the use of linear programming production can be forecast and optimise. e. Robots are use in situations that are dangerous to human beings.

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CHAPTER TWO BASIC COMPONENTS OF A COMPUTER SYSTEM THE COMPONENTS OF A COMPUTER A computer contains many electric, electronic and mechanical components known as hardware. These components include input devices, output devices, a system unit, storage devices, and communications devices. And also the invisible parts that control the workability of the computer system. The computer system is classified basically into two major parts:  Hardware  Software HARDWARE Hardware is the physical components of the computer system which you can touch. They are interconnected with cables of various shapes and sizes to facilitate data flow. An example of a piece of hardware is the system unit i.e. the box which houses the central processing unit (CPU) others are printer, scanner, speaker, mouse, keyboard etc. The Primary Components of Computer Hardware  Input devices.  Output devices.  Central Processing Unit (containing the control unit and the arithmetic/logic unit).  Storage devices.  Memory.  Communication devices. INPUT DEVICES An input device is any hardware component that allows you to enter data and instructions into a computer. Five widely used input devices are the keyboard, mouse, microphone, scanner, and Web cam. A computer keyboard contains keys you press to enter data into the computer. For security purposes, some keyboards include a fingerprint reader, which allows you to work with the computer only if your fingerprint is recognized. RESTRICTED

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A mouse is a small handheld device. With the mouse, you control movement of a small symbol on the screen, called the pointer, and you make selections from the screen. A microphone allows you to speak into the computer. A scanner converts printed material (such as text and pictures) into a form the computer can use. A Web cam is a digital video camera that allows you to create movies or take pictures and store them on the computer instead of on tape or film.

OUTPUT DEVICES An output device is any hardware component that conveys information to one or more people. Three commonly used output devices are a printer, a monitor, and speakers. A printer produces text and graphics on a physical medium such as paper. A monitor displays text, graphics, and videos on a screen. Speakers allow you to hear music, voice, and other audio (sounds).

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SYSTEM UNIT The system unit is a case that contains the electronic components of the computer that are used to process data. The circuitry of the system unit usually is part of or is connected to a circuit board called the motherboard. Two main components on the motherboard are the processor and memory. The processor also called a CPU (central processing unit) is the electronic component that interprets and carries out the basic instructions that operate the computer. Memory consists of electronic components that store instructions waiting to be executed and data needed by those instructions. Although some forms of memory are permanent, most memory keeps data and instructions temporarily, which mean its contents, are erased when the computer is shut off.

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STORAGE DEVICES Storage holds data, instructions, and information for future use. For example, computers can store hundreds of millions of customer names and addresses. Storage holds these items permanently. A computer keeps data, instructions, and information on storage media. Examples of storage media are USB flash drives, hard disks, optical discs, and memory cards. A storage device records (writes) and/or retrieves (reads) items to and from storage media. Drives and readers/writers, which are types of storage devices, accept a specific kind of storage media. For example, a DVD drive (storage device) accepts a DVD (storage media). Storage devices often function as a source of input because they transfer items from storage to memory. A USB flash drive is a portable storage device that is small and lightweight enough to be transported on a keychain or in a pocket. The average USB flash drive can hold about 4 billion characters. You plug a USB flash drive in a special, easily accessible opening on the computer. A hard disk provides much greater storage capacity than a USB flash drive. The average hard disk can hold more than 320 billion characters. Hard disks are enclosed in an airtight, sealed case. Although some are portable, most are housed inside the system unit. Portable hard disks are either external

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or removable. An external hard disk is a separate, freestanding unit, whereas you insert and remove a removable hard disk from the computer or a device connected to the computer. An optical disc is a flat, round, portable metal disc with a plastic coating. CDs, DVDs, and Blu-ray Discs are three types of optical discs. A CD can hold from 650 million to 1 billion characters. Some DVDs can store two full-length movies or 17 billion characters. Blu-ray Discs can store about 46 hours of standard video, or 100 billion characters. Some mobile devices, such as digital cameras, use memory cards as the storage media. You can use a card reader/writer to transfer the stored items, such as digital photos, from the memory card to a computer or printer. COMMUNICATION DEVICES A communications device is a hardware component that enables a computer to send (transmit) and receive data, instructions, and information to and from one or more computers or mobile devices. Widely used communications devices modem and NIC.  A modem is a communication device used to connect computers over telephone lines.  A Network Interface Card (NIC) is used with cable to connect computers that are relatively close together such as those in the same building (Local Area Network LAN). Communications occur over cables, telephone lines, cellular radio networks, satellites, and other transmission media. Some transmission media, such as satellites and cellular radio networks, are wireless, which means they have no physical lines or wires.

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CHAPTER THREE COMPUTER CATEGORIZATION Industry experts typically classify computers in seven categories: personal computers (desktop), mobile computers and mobile devices, game consoles, servers, mainframes, supercomputers, and embedded computers. A o puter s size, speed, pro essi g po er, a d pri e deter i e the ategor it best fits. Due to rapidly changing technology, however, the distinction among categories is not always clear-cut. This trend of computers and devices with technologies that overlap, called convergence, leads to computer manufacturers continually releasing newer models that include similar functionality and features. For example, newer cell phones often include media player, camera, and Web browsing capabilities. As devices converge, users need fewer devices for the functionality that they require. When consumers replace out dated computers and devices, they should dispose of them properly.

PERSONAL COMPUTER A personal computer is a computer that can perform all of its input, processing, output, and storage activities by itself. A personal computer contains a processor, memory, and one or more input, output, and storage devices. Personal computers also often contain a communications device. Two popular architectures of personal computers are the Desktop Computers and the Mobile Computers. DESKTOP COMPUTERS A desktop computer is designed so that the system unit, input devices, output devices, and any other devices fit entirely on or under a desk or table. In many models, the system unit is a tall and narrow tower, which can sit on the floor vertically — if desktop space is limited. Some desktop computers function as a server on a network. Others, such as a gaming desktop computer and home theatre PC, target a specific audience. The gaming desktop computer offers high-quality audio, video, and graphics with optimal performance for sophisticated single-user and networked or Internet multiplayer games. A home theatre PC (HTPC) combines the features of a high-definition video/audio RESTRICTED

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entertainment system with a desktop computer that is designed to be connected to a television and includes a Blu-ray Disc, digital video recorder, and digital cable television connectivity. These high-end computers cost more than the basic desktop computer. Another expensive, powerful desktop computer is the workstation, which is geared for work that requires intense calculations and graphics capabilities. An architect uses a workstation to design buildings and homes. A graphic artist uses a workstation to create computer-animated special effects for full-length motion pictures and video games. MOBILE COMPUTERS/MOBILE DEVICES A mobile computer is a personal computer you can carry from place to place. Similarly, a mobile device is a computing device small enough to hold in your hand. The most popular type of mobile computer is the Notebook computer. The following sections discuss the notebook computer and widely used mobile devices. Notebook Computers (Laptop) A notebook computer, also called a laptop computer, is a portable, personal computer often design...