Computer hardware course pdf download
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. 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. 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. There are many websites like computer-pdf. They usually come in the form of a textbook and you will get access to a knowledge data base that is useful even for people with some IT knowledge. These PDF files also contain exercises , examples of practical work and other things that will make the learning process easier and simpler.
All it takes is a computer, access to the Internet and of course — patience and willpower. It is available in only three editions. When the computer is switched on, it asks the user which operating system he would like to use and, after a short time, it starts with the default operating system.
In case the user wants to use a different operating systems, he obviously must restart the computer. When this happens, it is usually caused by the program that is used and therefore the first thing to do is to try to close the current program.
If this does not improve the situation, the only other solution left is to turn off the computer. Paolo Coletti 1. In any case all the current unsaved work will be lost; in the last two cases the operating system can sometimes be damaged but very often it will repair by itself the next time the computer is turned on.
Therefore it is always a very good idea to save very often the current work, especially when it is important, urgent, or difficult to redo. Keyboards and languages Before starting this section it is necessary to take a close look at your keyboard.
Another operation which can be useful in a multilanguage environment is changing the keyboard. While this can be done from the Language menu of the Control Panel, it is much easier to adjust it directly from the right side of the application bar, simply clicking on keyboard icon and selecting the appropriate one. File system Before starting this section it is necessary to do the following operations: 1.
In this way extensions see section 2. Page 8 of 33 Edition 8. Paolo Coletti 2. Files and directories Software is stored on storage devices in a special container called file. The operating system uses a lot of files for itself and for its data, a program usually uses one file for itself and other files for its data, and the user uses some files for his data.
A file is represented by a small picture called icon. Another special object is the directory or folder, which is basically a container for files and other directories and is represented with an icon depicting a yellow closed or open folder. Double clicking on a directory opens a new window which presents the directory content. Each storage device is a big directory, accessible from My Computer window, which contains directories and files.
Each file and directory can be univocally identified by its absolute path or address. While, the HPeDiag. Note that, for Windows operating system, capital or small caps letters in paths are perfectly equal. A special and tricky object is the link or shortcut. Although its icon looks like a file icon, the small curved arrow on the left corner clearly indicates that this object is a link. A link is simply an address to a file or directory, it is not a real file or directory.
When the user clicks on the link, the computer behaves exactly as if the user is clicking on the real file or directory if Windows can find the real one, which is not the case if in the meantime somebody deleted or moved it.
Therefore it is a good idea for novice users to avoid using links at all. If no program is associated with that file type, Windows asks the user which program should open the file. Copying a file means reproducing it to another location or to the same location with a different name. Copying a directory means reproducing it to another location, or to the same location with a different name, together with its entire tree of subdirectories and files.
If a plus symbol does not appear, press CTRL key to have it appear while dragging. Point the mouse to the destination and click the right mouse button. Moving a file means moving it to another location losing the file in the original place. Moving a directory means moving it to another location together with its entire tree of subdirectories and files.
A link is created in the same directory. Deleting a file means often putting it into the trash can where it can be recuperated unless the trash can is emptied. Deleting a directory means putting it to the trash can together with its entire tree of subdirectories and files. Pay special attention, since not always the trash can works as user expects and sometimes files are deleted without passing through the trash can.
To rename a file or directory, simply select the object, click on the name and retype it. Usually Windows accepts most names, but novice users should stick with only letters, numbers and spaces, since other characters may be forbidden. After the creation, rename it. Sometimes files occupy a lot of space and need to be reduced to save disk space or to be sent by email; other times files must be put in a package to remain together or to be sent as a single file via email.
To compress a set of files and directories: 1. When double clicking on a compressed file, if the compression program is properly installed, it will open in a window as if it were a directory.
Files can be copied from this window to a real directory simply dragging them to the directory. File types Windows identifies a file type by its extension, which is everything after the last dot in the filename.
Usually it is a 3 or 4 character acronym. Using the file extension, Windows knows the file type and decides which program will open that file. If the file extension does not show up, follow the instructions at section 2. The most important file types are: Edition 8. File permissions For each file Windows 7 operative system uses a permission. The security dialog box shows the list of users or groups of users who may access this object, while not listed users may not access it.
The owner of the file usually has full control on it and may change permissions or add new authorized groups or users. A special group is the Administrators group containing the users involved in technical administration of computers which has full control on every object. These are called network folders.
Some of them are: Page 12 of 33 Edition 8. Roaming user profile at UNIBZ Whenever the user logs in on a new computer, usually he should find a complete new profile Desktop, icons, Documents, configuration , which is obviously very annoying. This mechanism, called roaming user profile, works fine only if the user is not using too much disk space which is usually MB, but it is a good idea to stay below MB. If the user is over quota, the system sends a warning via email to the user and, if the user remains over quota, this mechanism does not work anymore.
Moreover, if the user still remains over quota, he will be forbidden from saving any file on the computer he is currently using. Therefore it is a good idea to always work on a USB pen drive which is then copied on another personal computer and to periodically check the disk space looking at the proprieties of this directory. If a warning email has been received or, even worse, roaming user profile does not work anymore, files need to be deleted not from the current computer since the mechanism is not working anymore but directly going through this directory.
Paolo Coletti Basic Computer course book 3. Without entering into technical details, this section will explore the situations in which a novice user can find himself in troubles and how he can try to survive dialoguing with network administrators in their own strange technical language.
Technical aspects A computer network is a set of devices which communicate and share resources. Server and client A computer network interaction is based on the client server architecture.
When considering a single interaction, one computer is the server and the other one is the client. The server is the computer which is offering its resource, usually programmed to wait until someone asks for its resource.
The client is the computer which uses the resource, which sends the request to a waiting server. The same computer may be the client for a service and the server for another service.
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