Hardware course pdf

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. Floppy diskettes, hard disk, tapes and optical disks come under the category of external storage devices or ancillary storage devices.

These devices are very sensitive to environmental conditions humidity and temperature as well as to external magnetic fields and need to be stored carefully. Floppy disks are primarily used on PCs. Information on a floppy disk is recorded in the magnetized states of particles of iron oxides evenly placed upon concentric circles known as tracks. It is a non-removable enclosed magnetic disk included in most PCs. It contains a stack of metal platters, each coated with iron oxide, that spin on a spindle and the entire unit is encased in a sealed chamber.

This is plastic tape, usually made of Mylar that is coated with iron oxide, thereby enabling the introduction writing ; retention memory and reading of magnetically recorded information. The best use of tape storage is for data that you do not use very often. An optical disc drive ODD is a disk drive that uses laser light or electromagnetic waves for reading or writing data to or from optical discs normally CD-ROM. It is a data storage device that includes flash memory with an integrated USB interface.

USB flash drives are typically removable and rewritable, and physically much smaller than an optical disc. Peripheral devices are devices connected to the computer externally. If a peripheral device is disconnected, the computer will still be able to work; only functions performed by this peripheral device will not be available.

Here are the most used types of peripheral devices:. The most common and very popular input device which helps in inputting data to the computer. It consists of keys that are capable of inputting alphabets, numbers and special characters.

You can also navigate using the keyboard and perform shortcut functions. Mouse is the most popular pointing device and cursor-control device having a small palm size box with a round ball at its base which senses the movement of mouse and sends corresponding signals to CPU when the mouse buttons are pressed.

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. A netbook, which is a type of notebook computer, is smaller, lighter than and often not as powerful as a traditional notebook computer.

Most netbooks cost less than traditional notebook computers, usually only a few hundred dollars. An ultra-thin is another type of notebook computer that is lightweight and usually less than one-inch thick. Some notebook computers have touch screens, allowing you to interact with the device by touching the screen, usually with the tip of a finger.

On a typical notebook computer, the keyboard is on top of the system unit, and the monitor attaches to the system unit with hinges. These computers weigh on average from 2. Most notebook computers can operate on batteries or a power supply or both. A digital pen looks like a small ink pen but uses pressure instead of ink. Users write or draw on a Tablet PC by pressing a finger or digital pen on the screen, and issue instructions by tapping on the screen.

One design of Tablet PC, called a convertible tablet, has an attached keyboard. Another design, which does not include a keyboard, is called a slate tablet and provides other means for typing. Some Tablet PCs also support voice input so that users can speak into the computer. Tablet PCs are useful especially for taking notes in lectures, at meetings, conferences, and other forums where the standard notebook computer is not practical.

Instead, these devices store programs and data permanently on special memory inside the system unit or on small storage media such as memory cards. You often can connect a mobile device to a personal computer to exchange information between the computer and the mobile device.

Some mobile devices are Internet-enabled, meaning they can connect to the Internet wirelessly. With an Internet-enabled device, users can chat, send e- mail and instant messages, and access the Web. Because of their reduced size, the screens on mobile devices are small, but usually are in colour. Popular types of mobile devices are smartphones and PDAs, e-book readers, handheld computers, portable media players, and digital cameras. Smart Phones and PDAs Offering the convenience of one-handed operation, a smart phone is an Internet enabled phone that usually also provides personal information management functions such as a calendar, an appointment book, an address book, a calculator, and a notepad.

In addition to basic phone capabilities, a smart phone allows you to send and receive e-mail messages and access the Web usually for an additional fee. Some smart phones communicate wirelessly with other devices or computers.

Many also function as a portable media player and include built-in digital cameras so that you can share photos or videos with others as soon as you capture the image. Many smart phones also offer a variety of application software such as word processing, spreadsheet, and games, and the capability of conducting live video conferences.

Others have a built-in mini keyboard on the front of the phone or a keyboard that slides in and out from behind the phone. Some have touch screens, where you press objects on the screen to make selections and enter text through an on-screen keyboard. Others include a stylus, which is similar to a digital pen but smaller and has less functionality. Types of messages users send with smart phones include text messages, instant messages, picture messages, and video messages.

A phone that can send picture messages often is called a camera phone. A phone that can send video messages often is called a video phone. A PDA personal digital assistant , which often looks like a smart phone, provides personal information management functions such as a calendar, an appointment book, an address book, a calculator, and a notepad.

A PDA differs from a smart phone in that it usually does not provide phone capabilities and may not be Internet-enabled, support voice input, have a built-in camera, or function as a portable media player. As smart phones and PDAs continue a trend of convergence, it is becoming increasingly difficult to differentiate between the two devices. This has led some manufacturers to refer to PDAs and smart phones simply as handhelds.

E-Book Readers An e-book reader short for electronic book reader , or e-reader, is a handheld device that is used primarily for reading e-books. In addition to books, users typically can purchase and read other forms of digital media such as newspapers and magazines. Most e-book readers have a touch screen and are Internet-enabled. These devices usually are smaller than tablet computers but larger than smart phones.

Many handheld computers communicate wirelessly with other devices or computers and also include a digital pen or stylus for input. Some handheld computers have miniature or specialized keyboards. Many handheld computers are industry-specific and serve the needs of mobile employees, such as meter readers and parcel delivery people, whose jobs require them to move from place to place.

Game Consoles A game console is a mobile computing device designed for single-player or multi-player video games. Weighing on average between two and nine pounds, the compact size of game consoles makes them easy to use at home, in the car, in a hotel, or any location that has an electrical outlet.

A handheld game console is small enough to fit in one hand, making it more portable than the standard game console. With the handheld game console, the controls screen, and speakers are built into the device. Because of their reduced size, the screens are small — three to four inches. Some models use cartridges to store games; others use a memory card or a miniature optical disc.

Many handheld game consoles can communicate wirelessly with other similar consoles for multiplayer gaming. Servers can support from two to several thousand connected computers at the same time.

In many cases, one server accesses data, information, and programs on another server. In other cases, people use personal computers or terminals to access data, information, and programs on a server.

A terminal is a device with a monitor, keyboard, and memory. Mainframes store tremendous amounts of data, instructions, and information. Most major corporations use mainframes for business activities. With mainframes, enterprises are able to bill millions of customers, prepare payroll for thousands of employees, and manage thousands of items in inventory.

One study reported that mainframes process more than 83 percent of transactions around the world. Mainframes also can act as servers in a network environment. Servers and other mainframes can access data and information from a mainframe. People also can access programs on the mainframe using terminals or personal computers. The fastest supercomputers are capable of processing more than one quadrillion instructions in a single second.

With weights that exceed tons, these computers can store more than 20, times the data and information of an average desktop computer. Applications requiring complex, sophisticated mathematical calculations use supercomputers. Large-scale simulations and applications in medicine, aerospace, automotive design, online banking, weather forecasting, nuclear energy research, and petroleum exploration use a supercomputer.

Embedded computers are everywhere — at home, in your car, and at work. The following list identifies a variety of everyday products that contain embedded computers. Because embedded computers are components in larger products, they usually are small and have limited hardware. These computers perform various functions, depending on the requirements of the product in which they reside. Embedded computers in printers, for example, monitor the amount of paper in the tray; check the ink or toner level, signal if a paper jam has occurred, and so on.

Any part that we can see or touch is the hard ware. Display Unit, printer etc. So, what else is required? It requires a set of instructions that tells the computer what is to be done with the input data. In computer terminology, this set of instructions is called a program and one or more programs are termed as software. Software used for computers may be of different types. The computer understands only machine language i. The software which does this translation is known as the system software.

Examples of system software are compilers and interpreters. Some are linked by expansion cards in expansion slots on the motherboard or connected directly on the ports via a cable attached on them. It has additional keys to handle special functions required by a computer.

Alphanumeric keys Comprises of alphabets A-Z , numbers and other characters. Special keys They perform specific functions. The Shift key when pressed with another key; alters the meaning of any alphanumeric key for e.

Ctrl, Alt and Del pressed together restarts the system. The Esc key is generally used to return to the previous menu or quit a program. The Cursor is a symbol displayed on the screen at the position where text or graphics will be inserted or deleted. The Cursor movement keys move the cursor on the screen. The Num-Lock is used to activate the numeric keys on the Numeric keypad. The Print Screen is used to print whatever is displayed on the screen.

Enter or Return is used to communicate the end of an instruction or data being keyed in through the keyboard. Caps lock is used for keying upper case alphabets.

Backspace is used to erase the character to the left of the cursor position. The Function keys are used to perform a set of operations using a single keystroke. The function keys can be defined as special purpose keys. In most of the software, pressing the F1 key will take you to the help feature. Other than these keys, 3 status indicators are present on the keyboard. There are two type of keyboard. Standard keyboard and Enhanced keyboard.

A mouse may have one, two or three buttons. The function each button depends on the program. Clicking the mouse results in selecting an option. Positioning a cursor with the mouse is easier for non-typists than pressing various key combinations.

With an appropriate software, a mouse can also be used to draw pictures. The Computer mouse is of three types and two classifications. SCANNER There are a number of situations when some information picture or text is available on paper and is needed on the computer disk for further manipulation.

A scanner is used for this purpose. A scanner scans an image and transforms it into graphics. These can be edited, manipulated and combined, and then printed. Scanners are used to reproduce photographs on the computer screen. These can be employed in training programs and in desktop publishing.

Types of scanner a Flat-bed scanner or desktop scanner b Optic scanner, looks like a camera c Hand held scanner PRINTER In order to get a copy of the output for later reference, you would require a printer.

Printers are capable of printing at a very high speed. Two commonly used printers are the dot-matrix printer and the laser printer. Printers are classified on the basis of a number of parameters like, the mechanism used for printing, speed of printing, quality of output, direction of printing, and the kind of interface they have with the computer.

Printers can be broadly classified as impact and non-impact printers. Let us understand this in detail. Impact Printers Impact printers work like typewriters. The characters are printed by striking the paper i. Impact printers can again be classified as Character printers and Line printers. Character Printers Character printers print one character at a time. Examples of character printers are. In a DMP, tiny hammers or pins strike the ribbon to produce the desired characters.

The print head consists of 9x7 arrays of pins. Characters to be printed are sent one at a time to the printer. The characters printed are a series of dots. Dot- matrix printers are inexpensive but noisy. They can print both text and graphics. They can print in any language without additional hardware change.

They can also be made to print in colour by changing ribbons. These printers are used everywhere to produce internal reports and memos needed by organizations. Daisy Wheel Printer In a daisy wheel printer, each petal has a character embossed on it. A motor spins the wheel along with it. When the desired character spins to the correct position, a print hammer strikes it to produce a character.

Line printers Line printers print one line at a time. Hence, line printers are generally faster than character printers. Printing speed varies from lines to lines per minute. Some of the line printers are drum printers and chain printers. These can continuously print for a few hours. Drum printers A drum printer consists of a cylindrical drum. The characters to be printed are embossed on it.

A set of print hammers one for each character in a line, are mounted in front of the drum. A character is printed by striking the appropriate hammer against the embossed character on the surface. The drum completes one revolution to print one line. The movement of the drum and the striking of the hammer must synchronize. Otherwise, the printing will not be uniform. As printer drums are costly they cannot be changed often. Chain Printer A chain printer has a steel band on which the characters are embossed.

The band is rotated at a high speed. As the band rotates, a hammer is activated when the desired character comes in front of it. For every character there will be a hammer. Here also, the hammer movement and the chain movement must be synchronized. The main advantage of the chain printer is that its chain can be easily changed.

Thus, different fonts and scripts can be used with the same printer. Some examples of the non-impact are laser printer, thermal printer, and inkjet printer. Laser Printer Laser printers print one page at a time. Laser printers use a light beam to form images on the paper using a toner ink as the medium. Laser printers are quiet workers.

They produce very high quality output both text and graphics. They are typically used publishing. Other Non-impact printers The other types of non-impact printers are thermal printers which use heat to print characters on paper and inkjet printers which use jets of ink to print characters on paper.

These printers are not in use as much as the laser printers. It can be used to create presentation-charts, graphics, tables and high quality technical drawings. There are two types of plotters: Drum and Flat Bed plotter. Drum Plotter The paper is placed over the drum that rotates back and forth. A carriage holding one or more pens is mounted horizontally across the drum. The carriage with the pens moves horizontally over the paper.

Each pen could be filled with different colours. This plotter has the ability to produce colour pictures. Flat Bed Plotter In flat bed plotter, the paper does not move. The carriage holding the pens should provide all motions. Inkjet plotters can also produce large drawings with different colours. The system unit consists of primary storage, arithmetic-logic unit, and the control unit.

The CPU interprets instructions to the computer, performs the logical and arithmetic processing operations, and causes the input and output operations to occur. It acts like the central nervous system for all the components though; it does not process any data. These separate areas are not fixed. The size of each area varies from application to application. ON state is represented by 1 and OFF state is represented by 0. A collection of 8 bits is known as a byte.

One Kilobyte represents bytes and one Megabyte represents Kilobytes. Ram Random Access Memory RAM is the area that is used for holding the programs and their data while the computer is working with them. RAM means the memory can be read from and written to randomly. These sets of programs perform the most basic control and supervisory operations for the computer. But the storage devices are not as fast as the CPU. Most of the time the CPU has to slow down because of these devices.

A small section of the high speed RAM is used to keep frequently needed information. So, one need some storage device to store data and other information.