compter harware requirement

Introduction As introduced in the previous lesson, in a network, computers and optional other devices are connected to share resources. When a computer or device A is requesting a resource from another computer or device B, the item A is referred to as a client. Because all or most items that are part of a network live in association or cooperation, almost any one of them can be referred to as a client. Based on this, there can be different types of clients. The most regularly used of them is referred to as a workstation. As its name implies, a workstation is a computer on which a person performs everyday regular assignments. A workstation is primarily a personal computer (PC). It can also be a laptop. You have probably used PCs so far. Almost any modern PC can be used as a workstation and participate on a network. Before building a computer network, when planning the workstations, you may be in one of the following scenarios. Using New Computers If you haven't bought the computer(s) but are planning to, refer to our section on purchasing or acquiring new computers in the Lesson 4. Using Existing Computers If you already have one or more computers that you plan to use as workstations, you can start by checking the hardware parts installed in the computer. The computer must meet the following requirements: Processor: An Intel Pentium or Celeron family of processors or an AMD K6/Athlon/Duron family of processors. The processor should have a 300 megahertz clock speed. A higher speed is recommended. To check the speed of the processor of a computer, you have many alternatives:   When the computer starts, you can access its BIOS by pressing F2 or F8 depending on the computer, the model or the manufacturer From the computer's desktop, if it's running Windows 95 and later, you can right-click My Computer and click Properties You can open Control Panel and double-click System With these two previous options, you can see the processor's speed in the Computer section of the General property page. As another alternative to check the computer's processor, from Control Panel, you can double-click System, click the Hardware tab, and click Device Manager. In the Device Manager window, expand the Processors node and double-click the first node under Processors. Here is an example: In most cases, if your computer is running Microsoft Windows XP Home Edition, it should be ready for Windows XP Professional. If the computer is running another operating system but it appears to be too slow, you can replace its processor with a faster one. Before replacing a processor, you must first find out what type of processor your computer use. You cannot just replace any processor for another. To know the type of processor your computer uses, you have three options: You can check the documentation (manual or user guide) that came with your computer. A page in it should describe the type of processor your computer is using. You can write it down and, when you go to a computer store or to a web store and use this description to purchase a new one. You can purchase a new processor from a computer store or from one of the following web sites:   http://www.tigerdirect.com http://www.bestbuy.com You can open the computer. In this case, remove the processor. Take it to a computer store and tell the sales people that you want a faster processor You can call the manufacturer of your computer. They will ask the serial number or the make/model. They will tell you the type of processor installed in it. You can also tell them that you want to purchase a faster processor If you purchase or acquire a processor, it is usually easy to install and it comes with easy-to-follow instructions. You will need to open the computer. It may be a good idea to take it to a computer store or a computer repair shop and have them replace the processor for you RAM: The computer must have a memory of at least 64 megabytes (MB). As memory is not particularly expensive nowadays, you should upgrade the computer's memory to at least 512MB To check the amount of RAM your computer has:   When the computer starts, you can access its BIOS by pressing F2 or F8 depending on the computer, the model or the manufacturer From the desktop of a Windows 95 and later computer,  you can right-click My Computer and click Properties You can open Control Panel and double-click System Any of these two options would show the computer's memory in the General  property page under the Computer section. Here is an example: If your computer doesn't have enough memory, you can increase it. Like a processor, different computers use different types of memory. Before changing or increasing the memory of your computer, you should find out what type it takes. As mentioned for the processor, you can get this information by consulting the manual it came with, by opening the computer, or by calling the manufacturer. Computer memory has not been very expensive lately. You can purchase the one appropriate for your computer from a computer, from the manufacturer of your computer, or from a web store. Once you get the memory, you can open the computer and insert the new memory in the sockets next to the existing memory Hard Drive: Before installing Microsoft Windows XP Professional on an existing computer, make sure the hard drive has the appropriate capacity to handle the OS. To find out how much space your hard drive has, you can open Windows Explorer or My Computer, right-click the C:\ drive and click Properties. Here is an example:   The computer may have more than one drive or many partitions. Here is an example: In this case, you can check the drive or partition you intend to use to install the new operating system. The hard drive or the partition you intend to use should have at least 1.5 gigabytes (GB) of available hard disk space Video: The computer should have Super VGA video adapter and be able to handle at least an 800 x 600 or higher-resolution. To check the current video resolution of your computer, right-click the desktop and click Properties. You can also open Control Panel and double-click Display. In the Display Properties, click Settings:   To check the video adapter of your computer, click Advanced and click the Adapter tab. Here is an example: CD-ROM or DVD drive: Unless you got this computer a long time ago, it should already have either a CD or a DVD drive or both. If it doesn't, you use one of its empty bays to install one. If the installation seems difficult or something you don't feel like doing, you can purchase an external drive. To do this, you can shop to a computer store or a web store   Using Barebone Computers A computer is referred to as "barebone" if it's built almost from scratch by assembling its parts. You can build your own computer or you can purchase one. You can purchase or acquire a computer with all parts or only some parts. To get this type of computers: You can go to one of those small computer stores on major streets, describe to them what you want. They would get the parts together and assemble them for you You can shop in a web store such as http://www.tigerdirect.com and click the "Barebone" link You can investigate how to build a computer from scratch, purchase the parts one by one, and assemble them yourself You may have a computer without an operating system. For example, you might have formatted the hard drive or you might have created two or more partitions on the hard drive and (may be intentionally) loose the operating system. You may plan to use such a computer as a workstation. Whether you build your own computer or use one without an operating system, before installing Microsoft Windows XP Professional, make sure the computer meets these hardware requirements: A processor with 300 megahertz or higher processor clock speed recommended; 233 MHz minimum required (single or dual processor system);* Intel Pentium/Celeron family, or AMD K6/Athlon/Duron family, or compatible processor recommended 128 megabytes (MB) of RAM or higher recommended (64 MB minimum supported; may limit performance and some features) 1.5 gigabytes (GB) of available hard disk space Super VGA (800 x 600) or higher-resolution video adapter CD-ROM or DVD drive As many USB ports as possible Mouse and Keyboard ports Because building a barebone depends on your goals, we will not review here the parts to acquire or the steps performed.

 

Laptop or Notebook Computers Because of their flexibility and requirements of users commute, laptops are the prime candidates of a network. If you plan to purchase one or more, refer to our section on purchasing or acquiring new computers in the Lesson 4. Computer Accessories and Peripherals   Keyboard and Mouse When using a computer, there are different ways you can control it. The primary accessories used to perform routine operations are the keyboard and the mouse. If you haven't bought the computer(s) but are planning to, refer to our section on purchasing or acquiring new computers in the Lesson 4. If you are using an existing computer for your network and if either the mouse, the keyboard, or both of these items are missing or not functioning, you should get or replace the failing one. If you are building your own computer or are acquiring a barebone, make sure you purchase a keyboard and a mouse for the computer. There are two main ways you install a keyboard or a mouse. If the item is supplied to you with a PS/2 port, connect the end of its cable to the appropriate port, usually in the back of the computer. Many items nowadays are meant to connect to a USB port. In this case, you should be able to connect the end cable of the item to any USB port on your computer. There are also wireless keyboards and mice. If you purchase them, they come with easy-to-follow instructions to install and configure them. Our advice is that you still should always have a PS/2 keyboard and mouse with you. Monitors A monitor is a display that a user looks at when performing daily assignments. You can buy a monitor from a computer store or from a web store. When purchasing a monitor, keep in mind that users may stare at it all day long. You should put as much care as possible when acquiring one. If you haven't bought the computer(s) and monitors, you can refer to our section onpurchasing or acquiring new computers in the Lesson 4. If you are using an existing computer, it may have a monitor attached to it already. You can still replace it if you want. If you are using a barebone computer, make sure you purchase a monitor and attach it to it. It is usually easy to connect a monitor to a computer. It uses a unique connector usually in the back of the computer. Printers If you want your users to be able to print, you can use an existing printer or purchase a new one. The simplest printers will be attached to one computer and "shared" to allow other computers to access it.

 

Network Distribution   Introduction Building a network consists partly of connecting the computers as we saw in Lesson 1: One way to do this is to use cables.   Network Cables Cable is used to connect computers. Although we are planning to use as much wireless as possible, you should always have one or more cables around. In our network, we will use Category 5 cable RJ-45. The ends of the cable appear as follows: They can be in different colors: You can purchase this cable from a web store on the Internet. Probably the fastest way to get this cable is to go to a computer store. When purchasing it, get something with at least 6ft. Introduction to Network Distributors In our introduction to networks, We mentioned that you could connect one computer to another. This can be done using their serial ports: This is possible because almost every computer has a serial port. If you have to connect many computers to produce a network, this serial connection would not be practical. The solution is to use a central object that the computers and other resources can connect to, and then this object becomes responsible to “distribute” or manage network traffic: The most regularly used types of network distributors are the hub, the router, and the switch. Hub A hub is rectangular box that is used as the central object on which computers and other devices are connected. To make this possible, a hub is equipped with small holes called ports. Here is an example of a hub: Although this appears with 4 ports, depending on its type, a hub can be equipped with 4, 5, 12, or more ports. Here is an example of a hub with 8 ports: When configuring it, you connect an RJ-45 cable from the network card of a computer to one port of the hub. In most cases for a home-based or a small business network, you may not need a hub. Routers: Wired or Wireless Like a hub, a router is another type of device that acts as the central point among computers and other devices that are part of a network. Here is an example of a wired router: A router functions a little differently than a hub. In fact, a router can be considered a little "intelligent" than the hub. Like a hub, the computers and other devices are connected to a router using network cables. To make this possible, a router is equipped with holes, called ports, in the back. Here is an example: Based on advances in the previous years from IEEE and other organizations or research companies, there are wireless routers. With this type, the computers and devices connect to the router using microwaves (no physical cable). In our (small) network, we wish to use a wireless router. Therefore, this is the kind we suggest you purchase. You can purchase a wireless router from a computer store or on the internet (http://www.tigerdirect.com, http://www.3com.com, http://www.provantage.com, etc). You can also buy a wireless router from a computer store. Wired Network Cards In order to connect to a network, a computer must be equipped with a device called a network card. A network card, or a network adapter, also called a network interface card, or NIC, allows a computer to connect to the exterior. If you buy a computer from one of those popular stores or big companies on the Internet, most of their computers have a network card tested and already. You can reliably use it. If you go to a store that sells or manufactures computers, you can ask them to install or make sure that the computer has a network card. If you have a computer that doesn’t have a network card, you can install one. If you have a computer that already has a network card, you can still replace it. When it comes to their installation, there are roughly two categories of network cards: internal and external. An internal network card looks like a printed circuit board with some objects "attached" or "glued" to it and it appears as follows: What this card looks like may not be particularly important and it may depend on the manufacturer but some of its aspects particularly are. To start, there are two types of cards and you should know which one is suited (or which one you want to use) for your computer. One type of NICs uses a peripheral component interconnect (PCI) connection. Another type uses industry standard architecture (ISA). There are two primary ways you replace a network card. In most cases, you will remove the card your computer already has and install a new one. In some other cases, you will only add a new card but you cannot replace the existing one because it is part of the motherboard (I have found that out lately when opening a few computers for my users (I was not aware of that)). The area where you add a network card is called a slot. To proceed, you must find out what your computer has to offer when it comes to network cards. To do this, you have three main alternatives.  You can open the computer and examine the available slots of your computer. They are usually located inside of what would be considered as the back (wall) of the computer (if you know where you connect the monitor, you should be able to locate the area that has the slots. Unfortunately, unless you have experience with this, simply looking at the slots will not tell you what type of connection you are dealing with. The second alternative is to open the manual that came with you computer (provided you haven’t thrown it away). The manual usually lists the (types of) slots that your computer provides and where they are located. The last alternative to knowing the types of slots that your computer provides is to contact the company that sold you the computer. They usually know, provided you can get a human being on the phone, as long as you give them the model of the computer. Once you know the type of slot available to you, you can go on the Internet or to a computer store and buy an appropriate network card. One of the most important characteristics of a network card is the speed it can use to carry information. The speeds are either 10 or 100Mbps (megabits per second). When buying a network card, you should pay attention to this. Here are some suggested links where you can buy computer products: http://www.provantage.com http://www.tigerdirect.com http://www.cdw.com Your computer manufacturer also may sell network cards intended for your computer. After buying a network card intended for internal installation, you can/must install it. The network card should come with a manual and all (easy to follow) instructions. You can also install the network card after setting up the computer, which we will cover in Lesson 4. We mentioned that a network card could also be used or installed externally. This can be done using USB. To use it, you can go to a computer store or find a web site that sells them. The device you buy may look like this: Here is another example: If you buy one of these objects, its documentation will guide you. Wireless Network Cards Depending on your network budget or your customer's, instead of using wired network cards, you can use wireless ones. A wireless NIC appears as its wired counterpart. Here are two examples: Overall, the physical installation of a wireless network card follows the same rules as that of a wired NIC. They normally come with easy to follow instructions but it may be a good idea to install the wireless network adapters after installing the wireless router. Also, it may be a good idea to purchase the network cards and the wireless router from the same manufacturer. Most desktop computers (workstations) come without a wireless network card. If you purchase a computer from one of the big companies on the Internet, you can choose to have it shipped with a wireless NIC. Some companies may propose to install it before shipping the computer. If you buy a computer from a store and if you want to use wireless networking, you can buy a wireless network card separately. As stated already, a wireless network card is not particularly difficult to install. Besides the wireless network cards that can be installed inside the computer, you can use external cards. These are installed using a USB port. Here is an example of a USB adapter: Here is another example: These adapters, like most USB objects, are easy to connect and use. Like the other hardware parts, when you connect these, the computer detects them and helps you get them ready for use. Unlike desktop computers, most laptops nowadays come equipped with a wireless network card (in fact most laptops today ship with both a wired and a wireless adapters). This means that, after purchasing or acquiring a laptop, you should simply check whether it has a wireless adapter. The way you check this depends on the laptop. Therefore, check its documentation. If your laptop happens not to a have a wireless adapter and you want to use one, you have two main options. The classic style of adapter appears as the following two examples: This adapter is inserted on a side of the laptop. Normally, you would easily see its port as there is usually only one that is suited for this type of card on the laptop. As you may guess, this card can be inserted and removed at will. Network Accessories   Printers If you attach a printer to one computer and share it, when that computer is off, nobody can print. An alternative is to purchase a network printer. That is, a printer that will directly connect to the network and people can print to it any time. There are two types of printers in this case: Some printers come equipped with a network card. In this case, as we will learn in Lesson 5, you can use an RJ-45 cable to connect it to a router or a hub Some printers are equipped for a parallel port. To connect them to a network, you can purchase what is referred to as a print server (or a Jet-Direct card). The manufacturer of the printer can sell it to you If you are using a wireless network, you can purchase a wireless print server. This allows you to connect almost any type of printer, with or without a network card, to the network. You can purchase a wireless print server from a computer store or from a web store. It is usually easy to install as it comes with easy-to-follow instructions. Internet Service Provider (ISP) An Internet Service Provider (ISP) is a company that serves as the intermediary between your network (or you) and the Internet. If you plan to give access to the Internet to the members of your network, you may need this type of company. You can start by checking with your local telephone company or your local TV cable company. Firewall Firewall is a security measure that consists of protecting your network from intruders. This is primarily important if you plan to connect your network to the Internet. There are two types of firewalls: hardware and software. For a small network, when buying a router, you can inquire as to whether it has a built-in firewall. Many of them do. Alternatively, you can use or configure one of the computers of your network as a firewall.

computer hardware

What is Hardware?

Your PC (Personal Computer) is a system, consisting of many components. Some of those components, like Windows XP, and all your other programs, are software. The stuff you can actually see and touch, and would likely break if you threw it out a fifth-story window, is hardware.

Not everybody has exactly the same hardware. But those of you who have a desktop system, like the example shown in Figure 1, probably have most of the components shown in that same figure. Those of you with notebook computers probably have most of the same components. Only in your case the components are all integrated into a single book-sized portable unit.

Figure 1

The system unit is the actual computer; everything else is called a peripheral device. Your computer's system unit probably has at least one floppy disk drive, and one CD or DVD drive, into which you can insert floppy disks and CDs. There's another disk drive, called the hard disk inside the system unit, as shown in Figure 2. You can't remove that disk, or even see it. But it's there. And everything that's currently "in your computer" is actually stored on that hard disk. (We know this because there is no place else inside the computer where you can store information!).

Figure 2

The floppy drive and CD drive are often referred to as drives with removable media or removable drives for short, because you can remove whatever disk is currently in the drive, and replace it with another. Your computer's hard disk can store as much information as tens of thousands of floppy disks, so don't worry about running out of space on your hard disk any time soon. As a rule, you want to store everything you create or download on your hard disk. Use the floppy disks and CDs to send copies of files through the mail, or to make backup copies of important items.

Random Access Memory (RAM)

There's too much "stuff" on your computer's hard disk to use it all at the same time. During the average session sitting at the computer, you'll probably use only a small amount of all that's available. The stuff you're working with at any given moment is stored in random access memory (often abbreviated RAM, and often called simply "memory"). The advantage using RAM to store whatever you're working on at the moment is that RAM is very fast. Much faster than any disk. For you, "fast" translates to less time waiting and more time being productive.

So if RAM is so fast, why not put everything in it? Why have a hard disk at all? The answer to that lies in the fact that RAM is volatile. As soon as the computer is shut off, whether intentionally or by an accidental power outage, every thing in RAM disappears, just as quickly as a light bulb goes out when the plug is pulled. So you don't want to rely on RAM to hold everything. A disk, on the other hand, holds its information whether the power is on or off.

The Hard Disk

All of the information that's "in your computer", so to speak, is stored on your computer's hard disk. You never see that actual hard disk because it's sealed inside a special housing and needs to stay that way. Unlike RAM, which is volatile, the hard disk can hold information forever -- with or without electricity. Most modern hard disks have tens of billions of bytes of storage space on them. Which, in English, means that you can create, save, and download files for months or years without using up all the storage space it provides.

In the unlikely event that you do manage to fill up your hard disk, Windows will start showing a little message on the screen that reads "You are running low on disk space" well in advance of any problems.  In fact, if that message appears, it won't until you're down to about 800 MB of free space. And 800 MB of empty space is equal to about 600 blank floppy disks. That's still plenty of room!

The Mouse

Obviously you know how to use your mouse, since you must have used it to get here. But let's take a look at the facts and buzzwords anyway. Your mouse probably has at least two buttons on it. The button on the left is called the primary mouse button, the button on the right is called the secondary mouse button or just the right mouse button. I'll just refer to them as the left and right mouse buttons. Many mice have a small wheel between the two mouse buttons, as illustrated in Figure 3.

Figure 3
 

The idea is to rest your hand comfortably on the mouse, with your index finger touching (but not pressing on) the left mouse button. Then, as you move the mouse, the mouse pointer (the little arrow on the screen) moves in the same direction. When moving the mouse, try to keep the buttons aimed toward the monitor -- don't "twist" the mouse as that just makes it all the harder to control the position of the mouse pointer.

If you find yourself reaching too far to get the mouse pointer where you want it to be on the screen, just pick up the mouse, move it to where it's comfortable to hold it, and place it back down on the mousepad or desk. The buzzwords that describe how you use the mouse are as follows:

• Point: To point to an item means to move the mouse pointer so that it's touching the item.
• Click: Point to the item, then tap (press and release) the left mouse button.
• Double-click: Point to the item, and tap the left mouse button twice in rapid succession - click-click as fast as you can.
• Right-click: Point to the item, then tap the mouse button on the right.
• Drag: Point to an item, then hold down the left mouse button as you move the mouse. To drop the item, release the left mouse button.
• Right-drag: Point to an item, then hold down the right mouse button as you move the mouse. To drop the item, release the right mouse button.

The Keyboard

Like the mouse, the keyboard is a means of interacting with your computer. You really only need to use the keyboard when you're typing text. Most of the keys on the keyboard are laid out like the keys on a typewriter. But there are some special keys like Esc (Escape), Ctrl (Control), and Alt (Alternate). There are also some keys across the top of the keyboard labeled F1, F2, F3, and so forth. Those are called the function keys, and the exact role they play depends on which program you happen to be using at the moment.

Most keyboards also have a numeric keypad with the keys laid out like the keys on a typical adding machine. If you're accustomed to using an adding machine, you might want to use the numeric keypad, rather than the numbers across the top of the keyboard, to type numbers. It doesn't really matter which keys you use. The numeric keypad is just there as a convenience to people who are accustomed to adding machines.

Figure 4

Most keyboards also contain a set of navigation keys. You can use the navigation keys to move around around through text on the screen. The navigation keys won't move the mouse pointer. Only the mouse moves the mouse pointer.

On smaller keyboards where space is limited, such as on a notebook computer, the navigation keys and numeric keypad might be one in the same. There will be a Num Lock key on the keypad. When the Num Lock key is "on", the numeric keypad keys type numbers. When the Num Lock key is "off", the navigation keys come into play. The Num Lock key acts as a toggle. Which is to say, when you tap it, it switches to the opposite state. For example, if Num Lock is on, tapping that key turns it off. If Num Lock is off, tapping that key turns Num Lock on.

Combination Keystrokes (Shortcut keys)

Those mysterious Ctrl and Alt keys are often used in combination with other keys to perform some task. We often refer to these combination keystrokes as shortcut keys, because they provide an alternative to using the mouse to select menu options in programs. Shortcut keys are always expressed as:

key1+key2

where the idea is to hold down key1, tap key2, then release key1. For example, to press Ctrl+Esc hold down the Ctrl key (usually with your pinkie), tap the Esc key, then release the Ctrl key. To press Alt+F you hold down the Alt key, tap the letter F, then release the Alt key.

personal area network

Wireless PAN

A wireless personal area network (WPAN) is a personal area network - a network for interconnecting devices centered around an individual person's workspace - in which the connections are wireless. Typically, a wireless personal area network uses some technology that permits communication within about 10 metres (33 ft) such as Bluetooth, which was used as the basis for a new standard, IEEE 802.15.

A WPAN could serve to interconnect all the ordinary computing and communicating devices that many people have on their desk or carry with them today - or it could serve a more specialized purpose such as allowing the surgeon and other team members to communicate during an operation.

A key concept in WPAN technology is known as "plugging in". In the ideal scenario, when any two WPAN-equipped devices come into close proximity (within several meters of each other) or within a few kilometers of a central server, they can communicate as if connected by a cable. Another important feature is the ability of each device to lock out other devices selectively, preventing needless interference or unauthorized access to information.

The technology for WPANs is in its infancy and is undergoing rapid development. Proposed operating frequencies are around 2.4 GHz in digital modes. The objective is to facilitate seamless operation among home or business devices and systems. Every device in a WPAN will be able to plug in to any other device in the same WPAN, provided they are within physical range of one another. In addition, WPANs worldwide will be interconnected. Thus, for example, an archeologist on site in Greece might use a PDA to directly access databases at theUniversity of Minnesota in Minneapolis, and to transmit findings to that database.

[edit]Connecting devices

Connecting devices allow hardware networking devices to communicate with each other. The three kinds of wireless technologies areBluetooth, infrared, and Wireless Fidelity (WiFi).

[edit]Bluetooth

Bluetooth uses short-range radio waves over distances up to approximately 10 metres. For example, Bluetooth devices such as a keyboards, pointing devices, audio head sets, printers may connect to Personal digital assistants (PDAs), cell phones, or computers wirelessly.

[edit]Infrared

Infrared communications (IR) or IrDA (Infrared Data Association) uses infrared light, which has a frequency below the human eye's sensitivity. It is used in cell phones and TV remote controls. Typical devices include printers, keyboards, and other serial data interfaces.^[1]

[edit]WiFi

WiFi (wireless fidelity) uses radio waves for connection over distances up to around 91 metres, usually in a local area network (LAN) environment. Wifi can be used to connect local area networks, to connect cellphones to the Internet to download music and other multimedia, to allow PC multimedia content to be stream to the TV (Wireless Multimedia Adapter), and to connect video game consoles to their networks (Nintendo WiFi Connection).