Free download computer hardware books pdf

Click here to sign up. Download Free PDF. Umar Haruna. A short summary of this paper. Download Download PDF. Translate PDF. 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 given to it.

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. As a result, communications also has become an essential element of the information processing cycle. What could take a man some hours to accomplish may take a computer a few seconds. Computers designed and built in the 80s are still functioning today. The computer does not require human supervision to function.

Every imaginable profession and business now uses it. 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.

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. Mini-computer: This is bigger than the micro —computer and it supports more than one user. PC or Desktop computer. These would further classify digital computers into. 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. 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. This device gave better performance to the computer and greatly reduced the size of the computer. Fourth Generation Computers: These are made from greatly enhanced integrated circuits.

They are the ones in use today. Fifth Generation Computers: These are the computers of the future. They will have artificial intelligence AI. 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. 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.

Hybrid computer: This is a computer that combines the feature of both Analogue and digital computer and is referred to as Anatel. The historical development of the computer can be associated with human activities such as calculating, counting and so on. 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 Abacus was probably invented by ancient Sumerians in 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 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 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. Then later in the 20th century, the modern computers came into the development, and their generations are characterised by their technology: a.

Although the tubes worked, they had many problems, as high power consumption and heat generation. The second-generation computers were the first successful commercial computers. The third generation computers came in the late s and were characterised by miniaturisation of components and use integrated circuits I. The fourth generation Computers are defined by the introduction of the microprocessor in The first personal computer falls into this category named IBM 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. 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 word- processing, spread sheet and other utilities. In Communications: This includes mobile telephone networks, communicating with satellite c. In Education: This includes, helping students in solving complex problems, easy reference and sources of information.

In Business: Through Internet and Networks, e-commence and e- Business are in operation, baking online, Shopping on-the net. In Remote Sensing: This Includes survey and weather forecasting etc. 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. In navigation and locating of positions by the use of GPS fire control system. 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. For keeping patients database: for record retrieving purposes. As operation aids. In drug monitoring and inventory keeping.

Computer is used in the industries for the following: a. In control rooms: For monitoring of production machineries and their control. 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.

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. In production forecasting: By the use of linear programming production can be forecast and optimise. Robots are use in situations that are dangerous to human beings.

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.

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. 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. 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.

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. 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.

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. 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 billion characters.

Hard disks are enclosed in an airtight, sealed case. Although some are portable, most are housed inside the system unit. 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. A CD can hold from 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 billion characters. Some mobile devices, such as digital cameras, use memory cards as the storage media. Widely used communications devices modem and NIC. 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.

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. 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. 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.

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.

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 designed to fit on your lap. Notebook computers are thin and lightweight, yet they can be as powerful as the average desktop computer. Hardware is any part of the computer that you can touch. The seeming miles of wires that get tangled on your desk, the CD drive, the monitor are all hardware. Software is a set of electronic instructions consisting of complex codes Programs that make the computer perform tasks.

Windows is a software, so is any other program that runs on your computer. While there are thousands of parts even in the smallest computers that make up its hardware, you are not required to know them all.

You only need to know about basic computer hardware. The CPU is considered the brain of the computer. It performs all types of data processing operations, stores data, intermediate results and instructions program. It controls the operation of all parts of computer. A CPU has 3 components as listed below. Think of the ALU as the logical part of the brain.

The ALU thinks in bits i. It is made up of a group of memory locations built directly into the CPU called registers. These are used to hold the data binary information that are being processed by the current instruction. Primary memory is memory that is part of the computer itself and necessary for its functioning.

It consists of mainly two types of memories:. As soon as the machine is switched off, data is erased. RAM is volatile. Volatile means that the data stored in memory is lost when we switch off the computer or if there is a power failure.

There are different types of RAM available. Some of them are described below. The memory from which we can only read but cannot write on it.

This type of memory is non-volatile. The information is stored permanently in such memories during manufacture. A ROM, stores such instructions that are required to start a computer.

This operation is referred to as bootstrap. The different types of ROM are given below. Geography Notes — Click. Indian Polity Notes — Click. Economics Notes — Click. General Science Notes — Click. Current Affairs Notes — Click. Maths Notes — Click. Reasoning Notes — Click. English Grammar Notes — Click. General Hindi Notes — Click.

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