Lesson 2 Hardware in ICT PDF

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The Hardware Technically speaking, hardware refers to the actual

physical components of a system. In an industrial manufacturing facility, these would be the pipes and valves through which steam, water, and other fluids would run; in ICT, these would include the chips, monitor, circuit boards, keyboards and printers. Where computing hardware is concerned, devices used for calculation and data storage have been around for as long as people needed to calculate, store and record the information needed for an agricultural way of life. Calendars had to be accurate so farmers would know when to plant crops. The number of livestock needed to be tracked, as too few livestock could mean there was much less food to eat. And as human societies continued to grow in complexity, the need for calculation and data storage devices grew. Merchants needed to know how much they made or lost on sales; the royal recorders needed to know how many people were present in the kingdom. Also, various societies used different kinds of computing devices. The Babylonians started using abacus from 2,400 B.C. to calculate sums, while the Incas used quipu, or knotted cords, to keep track of information. Analog computers were constructed in ancient Greek times to perform astronomical calculations, and both the Muslims and Chinese invented their own forms of astronomical calculating clocks. Slide rulers were invented in the 1620s to allow people to multiply easily, and these devices were used by engineers until the 1970s, when programmable calculators came into widespread use. The first machine which we would recognize as a computer as we know it was the first mechanical calculator theorized in 1623 by Wilhelm Schickard. This machine used cogs and gears similar to those used in clocks, but it was unfortunately destroyed by a fire as it was being constructed. Over the next few centuries, such individuals as Blaise Pascal, Gottfried Wilhelm von Leibniz and Charles Xavier Thomas worked to develop their own versions of computing machines. Mechanical computing machines remained in widespread use until the middle of the 20th century; the famous German cipher machine Enigma, for example, was based on mechanical gearing which the Germans used to deliver (they hoped) top secret messages to their military units in the field.

Punched cards came into being in the 1800s, which theoretically gave computing machines capability to be programmed-that is, to simulate any kind of calculating device simply by changing the commands stored in it. In reality, punched cards, which were made of stiff, lightweight cardboards, were rather cumbersome to use, particularly since the holes had to be accurately placed. If a punch card needed a hundred holes in it to give a particular instruction, however, and the person doing the punching punched 98 holes accurately and punched the 99th hole in the wrong place, the entire card would need to be throw away and the person doing the punching would have to start all over again. Despite their limitations, punched card computing machines were very useful, state-of-the-art equipment for several decades. The punched cards themselves were used to store information which would be mechanically punched into them by the machines, and were used for such activities as storing census information for the United States. The company that did this in 1890 eventually became IBM.

Computer Generations Technology inevitably advanced, and so did computing machines, with vacuum tubes, capacitors and other electrical devices taking the place of mechanical gears. The first electronic programmable computer was the famed ENIAC-Electronic Numerical Integrator And Computer-which was built in 1945 for the US Army to calculate the trajectory of ballistic missiles. Its size was huge - it occupied an entire room-and where processing power was concerned it was far less powerful than any digital wristwatch made today. It belonged to the first generation of computers and started the whole ball rolling. The design of the vacuum tubes used in first generation computers was essentially like that of a light bulb, with an electrical element in a vacuum glass case. This made them rather fragile and they also gave off a lot of heat; think of a thousand normal glass bulbs lighted on a wall and you'll get an idea of how hot ENIAC could get. The second generation of computers used transistors, which started to replace vacuum tubes in 1947. They were far smaller than vacuum tubes, consumed less energy and produced less heat to boot. These transistors were semiconductor devices, usually made out of small silicon blocks, or chips, and their great advantage was that the electrical component of a vacuum tube could be etched onto the chip with acid, rather than having an entire vacuum tube assembled, which speeded up production. The third generation of computers uses the integrated circuit (IC), which were essentially semiconductor blocks on which hundreds or thousands of different electronic devices (including individual transistors) and electrical circuits were etched. These began to be commonly used in the I960s, and advancements in etching technology enabled even more and more electronic devices and electrical circuits to be etched into them, enabling faster computer processing speeds for microprocessors and more memory to be stored in data storage devices. The microprocessor brought the fourth generation of 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 hand. The Intel 4004 chip, developed in 1971, located all the components of the computer—from the central processing unit and memory to input/output controls—on a single chip. In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh. Microprocessors also moved out of the realm of desktop computers and into many areas of life as more and more everyday products began to use microprocessors. As these small computers became 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. Fifth generation computing devices, based on artificial intelligence, are still in development, though there are some applications, such as voice recognition, that are being used today. The use of parallel processing and superconductors is helping to make artificial intelligence a reality. Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization.

Computer Hardware Types of Computers Computers are classified in many types or categories. A computer's size, speed, price and processing power are the basis for classifying computers. They are supercomputers, mainframes, servers and personal computers. Supercomputers. Supercomputers are the fastest computers in the world. They have very high processing capacity, speed of calculation and are able to perform multiple tasks. US government agencies such as NASA and universities such as MIT and Harvard have their own supercomputers. Some applications of supercomputers are for weather forecasting, climate change, molecular use of modeling, quantum physics, nuclear weapons simulation and many other military and scientific research requiring super fast and high volume of data calculations. Supercomputers occupy large spaces and emit high energy. Mainframe Computers. Today, mainframes refer to computers manufactured by IBM that are compatible and descendant of the Systemj360 line. They are used by large corporations and organizations for bulk data processing such as bank transactions, consumer statistics and large databases. They are less powerful than the supercomputers but are still capable of great processing speeds, multi-tasking capability and high data storage. Major users of mainframes are banks which they use to process information of depositors' transactions including of ATMs, making it possible to bank "on line". Server Computers. Server computers are used as the main computers in a network serving and connected to several other computers. They have the capability to handle multiple requests for data and other processing tasks. Server computers may be set aside for a specific application such as running a web server for an organization's web site.

Servers do not necessarily have a terminal (meaning monitor, keyboard and mouse) and in big applications are stacked together and placed in cabinets or special rooms. Personal Computers. A personal computer (PC) is a computer designed to be operated by an individual whose size, price and capabilities are determined by the usual application the person uses it for. The PC today would be either a desktop computer or a portable computer either a laptop or tablet computer.

Types of Personal Computers Desktop Computers A desktop computer is a personal computer (PC) in a set-up wherein it is located in one desk or table as opposed to the portable computers that you can carry wherever you want. Desktop computers come in a variety of sizes which is usually determined by the size of the motherboard. Nettop

Nettop is a new breed of desktop computers introduced by Intel. They are small in size and low-priced. The Asus Eee Box is an example of nettop that is already available in the market. New and better models are about to be released.

Laptop Computer A laptop or notebook computer is a small personal computer whose components, display, keyboard, pointing device, CPU and rechargeable battery are packed together in one single portable unit intended for mobile use. Laptop can be categorized as follows:

Desktop replacement - is a high performance and high capacity computer whose screen size is 17" and larger. This laptop is also called Media Center Laptop or Gaming Laptop. Standard laptop - the most common size notebook with screen range of 13- 15" which covers a wide range of features in microprocessor speeds and memory capacity. Features include an optical disk drive, card readers, USB port, wired and wi-fj network capability and a web cam. Subnotebook - sizes of less than 13" of screen size. Portability is the emphasis of this computer. These notebooks retain the standard features of a standard notebook but they are small in size, less weight and have longer battery life, but in most cases these notebooks do not have optical disc drive and reduced number of extension slots for USB and other connections. Netbook - is a small laptop built for both portability to and low price but its feature normally pales compared to a standard notebook. However, its features are adequate for basic internet functions of surfing and email and standard office applications such as word processing and spreadsheet programs. Netbooks have screen sizes of 10" and below and -.weighs between 0.6 to 1.2 kg.

Tablet PC - A tablet PC is a notebook equipped with a touchscreen which allows you to operate the computer using a digital pen or stylus. Fingertip may also be used. A keyboard or a mouse will not even be needed. Tablet PC offers flexibility and functionality which standard notebook cannot give but these gadgets usually come at a higher price.

Portable Computer - Portable computer is the smallest personal computer that is handheld or pocket sized. A Pocket PC is a handheld or pocket size computer running on Microsoft Windows Pocket PC edition with all the features of a modern desktop PC. Pocket PCs may have mobile phone features. Three types are available, Windows Mobile Classic (without phone), Windows Mobile Professional (with phone and touch screen) and Windows Mobile Standard (with phone but without touch screen). PDA (Personal Digital Assistant) is a handheld computer also called palmtop computers. Modern PDAs have phone capabilities, web browsers, internet CPU capabilities, music and video. Touch screen is a standard feature on most PDAs. A smart phone is a mobile phone with additional capabilities such as email and internet, keyboard, personal organizer, built-in camera, touch screen, ability to read PDF and Microsoft documents, music, photo and video viewing.

Gaming console or video game console is a mobile gaming computer device designed for playing video games. It is an entertainment electronic gadget that has controllers, console main unit, game programs and storage (like a hard disk, CDs or DVDs or memory cards). Popular models include Microsoft, Sony Playstation and Nintendo Wii.

Handheld gaming consoles are small in size which can be played anywhere. The monitors are smaller and they are powered by rechargeable batteries. Popular models include Nintendo DS Lite and Sony Play station Portable. Embedded Computers. Embedded computers are special-purpose computers designed to do one or more specific functions. They are usually included or embedded as part of a complete system such as in appliances, cars or special purpose devices that are as small as watches to as big as a nuclear power plant. They are usually designed to be reliable, smaller and cheaper. Examples of embedded computers are found in the following:

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Consumer electronics including mp3 players, digital camera, mobile phones, video game consoles, CD and DVD players, digital watches and many others. Household appliances such as microwave oven, washing machines, refrigerators -with digital controls and others. Computer devices and office equipment such as printers, copiers, fax machines and others. Cars have speed and cruise controls, anti lock brakes system, air bag controllers, navigation aids and others.

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Medical equipment such as electronic stethoscopes, vital sign monitors, medical imaging and others.

Components Inside the CPU Box Motherboard Also called the system board is the main base of the computer hardware system. All parts, components and devices connect to the motherboard. The motherboard is also the host of the CPU, the memory and all other essential elements of the computer. All other components are usually connected to it by a data cable. CPU Central Processing Unit is the brain of the computer and is inside the CPU box, placed on a special slot on the motherboard. The CPU is contained inside a small chip called the microprocessor. The CPU processes all the basic and complex instructions given to it.

Memory This is where data and programs are placed for execution by the CPU. The memory is also directly connected to the motherboard through a slot also called socket. There are three kinds of memory: RAM (Random Access Memory) also called the main memory. Data and programs are placed here when the CPU is processing Information in the RAM are lost when power is turned off. ROM (Read Only Memory) stores important programs. An example is the program to start the computer. ROM information cannot be changed even when power is turned off. CMOS (Complimentary Metal-Oxide Semiconductor) stores the date, calendar and current time of the computer. It is powered by batteries so that even when the computer is turned off, information inside it remains.

Internal Storage Internal storage is where data is kept for future use. This storage retains information even when power is turned off. The common internal storage is the hard disk but solid-state drive a high storage without moving parts is now available.

Power Supply The CPU, motherboard, hard disk, and other components inside the CPU box get their power source from the power supply.

Video Card Also known as the graphics accelerator card or simply graphics card is a computer component whose main function is to generate video and images to a monitor. Video cards are installed to improve the quality and speed in which images are displayed. Some video cards have functions such as TV tuner for cable or antenna based TV viewing, video capture for video cameras and to connect several monitors to one CPU. What Does the CPU Do The CPU executes a step by step instruction in its memory called the program. The CPU has two basic components; the arithmetic logic unit (ALU) and the control unit. These two components work together to do the computer processing. The CPU is also known as the microprocessor.

The ALU does the arithmetic and logical operations of the computer. The arithmetic function includes the basic math calculations such as addition, subtraction, multiplication and division. The logical function on the other hand compares whether a data is greater, less or equal to another and then certain action occurs. The control unit functions just like a traffic cop that directs the sequence of operation that the CPU follows. It determines what numbers to add and what data to compare in the ALU.

Machine Cycle There are four basic steps that the CPU does to process its operation: fetch, decode, execute, and store. The process is repeated again and again until the last instruction. This is also called the machine cycle. 1. Fetch is the process of getting a program instruction or data from memory 2. Decode is the process of translating these instructions or data that the CPU can understand and execute upon. 3. Execute is the process of carrying out the command. It is either an arithmetic or logical operation. 4. Store is the process of writing the result to memory. This memory is in the CPU itself and they are called registers. This memory is not the RAM or the hard disk.

Inside the Microprocessor or CPU Registers Inside the CPU are small but high-speed data storage called registers. Registers hold data and instructions temporarily but are transferred to the CPU for processing at very high speeds. Processors have different types of registers. Some are used to store location of instruction, store an instruction while CPU decodes it, store data while ALU computes it and store results of ALU calculation or control unit comparison.

System Clock The CPU system clock is generated by a quartz crystal. The system clock provides the fixed sequence in time that cannot be varied. The number of ticks in one cycle is called the clock rate. The faster the clock rate, the faster is the processor in processing instructions. Today's microprocessor clock rates are measured in gigahertz (GHz). Giga is a prefix denoting billions and hertz is one cycle per second. Therefore, one gigahertz (GHz) is one billion ticks of the system clock per second. A CPU that is rated at 1.6 GHz has 1.6 billions processor clock cycles per second. Therefore, it is preferable to have processor with a high clock rate.

CPU Cooling The CPU chip generates a lot of heat when processing and may burn up if not cooled. A cooling system is needed to ensure that the processor or chip is cooled to a level so that it will operate efficiently. Most processors are provided with cooling fans but may not be enough. External cooling is needed. Heat sink is a metal component attached to the CPU with fins design to dissipate heat and therefore cool the processor. Heat is absorbed by the heat sink and is dispensed to the air by the fin. Sometimes heat pipes are used to blow the heat away. Other computers use water cooling just like in cars. Water flows from the memory to the radiator-type grill that cools the water

The Computer Peripherals Peripheral is the physical equipment which includes the input devices, central processing unit and output devices. Computer components are really different devices with different tasks. These components are also called peripherals. All together they are called the computer hardware system. Input Devices The input devices are used to input data into the computer 1. Keyboard 2. Mouse (such as mechanical, optical, laser mouse, trackball) 3. Optical Character Recognition or OCR 4. Scanner (such as barcode reader, credit card reader, digitizing tablet) 5. Digital Camera 6. Video Recorder 7. Web...