How can I install Windows Server 2003 on my server?
As a Microsoft Windows Server 2003 support professional, one of your tasks may be to install the operating system.
Step #1: Plan your installation
When you run the Windows Server 2003 Setup program, you must provide information about how to install and configure the operating system. Thorough planning can make your installation of Windows Server 2003 more efficient by helping you to avoid potential problems during installation. An understanding of the configuration options will also help to ensure that you have properly configured your system.
I won't go into that part right now (I might later this month, no promises...) but here are some of the most important things you should take into consideration when planning for your Windows Server 2003 installation:
· Check System Requirements
· Check Hardware and Software Compatibility
· Determine Disk Partitioning Options
· Choose the Appropriate File System: FAT, FAT32, NTFS
· Decide on a Workgroup or Domain Installation
· Complete a Pre-Installation Checklist
After you made sure you can go on, start the installation process.
Step #2: Beginning the installation process
You can install Windows Server 2003 in several methods - all are valid and good, it all depends upon your needs and your limitations.
For example, you can install directly from a CD by booting your computer with the CD, or you can also copy the I386 folder from a CD and run the setup process by going into the I386 folder and using the WINNT or WINNT32 command (depending upon your existing operating system).
It doesn't matter how you run the setup process, but the moment it runs - all setup methods look alike.
Step #3: The text-based portion of the Setup program
The setup process begins loading a blue-looking text screen (not GUI). In that phase you will be asked to accept the EULA and choose a partition on which to install 2003, and if that partition is new, you'll be asked to format it by using either FAT, FAT32 or NTFS.
1. Start the computer from the CD.
2. You can press F6 if you need to install additional SCSI adapters or other mass-storage devices. If you do you will be asked to supply a floppy disk with the drivers and you CANNOT browse it (or a CD for that matter). Make sure you have one handy.
3. If you want, you can press F2 to run the ASR sequence. For that you need a good backup created by the Windows Server 2003 backup program, and the ASR floppy disk. If you plan to install a new copy of 2003 - don't do anything.
4. Setup will load all the needed files and drivers.
5. Select To Setup Windows Server 2003 Now. If you want, and if you have a previous installation of the OS, you can try to fix it by pressing R. If not, just press ENTER.
6. Read and accept the licensing agreement and press F8 if you accept it.
7. Select or create the partition on which you will install Windows Server 2003. Depending upon your existing disk configuration choose one of the following:
· If the hard disk is unpartitioned, you can create and size the partition on which you will install Windows Server 2003.
· If the hard disk is already partitioned, but has enough unpartitioned disk space, you can create an additional partition in the unpartitioned space.
· If the hard disk already has a partition that is large enough, you can install Windows Server 2003 on that partition. If the partition has an existing operating system, you will overwrite that operating system if you accept the default installation path. However, files other than the operating system files, such as program files and data files, will not be overwritten.
· If the hard disk has an existing partition, you can delete it to create more unpartitioned space for the new partition. Deleting an existing partition erases all data on that partition.
If you select a new partition during Setup, create and size only the partition on which you will install Windows Server 2003. After installation, use Disk Management to partition the remaining space on the hard disk.
8. Select a file system for the installation partition. After you create the partition on which you will install Windows Server 2003, you can use Setup to select the file system with which to format the partition. Windows Server 2003 supports the NTFS file system in addition to the file allocation table (FAT) and FAT32 file systems. Windows Server 2003, Windows XP Professional, Windows 2000, and Windows NT are the only Microsoft operating systems that you can use to gain access to data on a local hard disk that is formatted with NTFS. If you plan to gain access to files that are on a local Windows Server 2003 partition with the Microsoft Windows 95 or Windows 98 operating systems, you should format the partition with a FAT or FAT32 file system. We will use NTFS.
9. Setup will then begin copying necessary files from the installation point (CD, local I386 or network share).
10. Note: If you began the installation process from an MS-DOS floppy, make sure you have and run SMARTDRV from the floppy, otherwise the copying process will probably last more than an hour, perhaps even more. With SMARTDRV (or if setup was run by booting from CD) the copying will probably last a few minutes, no more than 5 max.
11. The computer will restart in graphical mode, and the installation will continue.
Step #4: The GUI-based portion of the Setup program
The setup process reboots and loads a GUI mode phase.
It will then begin to load device drivers based upon what it finds on your computer. You don't need to do anything at this stage.
1. Click Customize to change regional settings, if necessary.
· Current System Locale - Affects how programs display dates, times, currency, and numbers. Choose the locale that matches your location, for example, French (Canada).
· Current Keyboard Layout - Accommodates the special characters and symbols used in different languages. Your keyboard layout determines which characters appear when you press keys on the keyboard.
If you don't need to make any changes just press Next.
If you do need to make changes press Customize and add your System Locale etc.
Note for Hebrew users: Unlike W2K, it is SAFE and it is OK for you to install Hebrew language support at this phase.
To install Hebrew support:
After pressing Customize go to the Languages tab and select the "Install files for complex script and right-to-left languages".
A warning message will appear. Press Ok.
Warning: You must now press Apply!!!
Setup will copy the necessary files from the installation point.
You can now go to the Regional Options tab and select Israel in the Location drop-down list, and Hebrew in the Standards and Formats drop-down list. Click Ok.
Note: Read the Install Hebrew on Windows Server 2003 page for more info.
2. Type your name and organization.
3. Type the product key.
4. Enter the appropriate license type and number of purchased licenses.
5. Type the computer name and a password for the local Administrator account. The local Administrator account resides in the SAM of the computer, not in Active Directory. If you will be installing in a domain, you need either a pre-assigned computer name for which a domain account has been created, or the right to create a computer account within the domain.
6. If you enter a password that is blank or does not match the required complexity settings you will get a warning message.
7. Select the date, time, and time zone settings.
6. Setup will now install the networking components.
After a few seconds you will receive the Networking Settings window. BTW, if you have a NIC that is not in the HCL (see the What's the HCL? page) and Windows Server 2003 cannot detect it, or if you don't have a NIC at all, setup will skip this step and you will immediately go to the final phase of the setup process.
Press Next to accept the Typical settings option if you have one of the following situations:
· You have a functional DHCP on your network.
· You have a computer running Internet Connection Sharing (ICS).
· You're in a workgroup environment and do not plan to have any other servers or Active Directory at all, and all other workgroup members are configured in the same manner.
Otherwise select Custom Settings and press Next to customize your network settings.
7. Highlight the TCP/IP selection and press Properties.
In the General tab enter the required information. You must specify the IP address of the computer, and if you don't know what the Subnet Mask entry should be - you can simply place your mouse pointer over the empty area in the Subnet Mask box and click it. The OS will automatically select the value it thinks is good for the IP address you provided.
If you don't know what these values mean, or if you don't know what to write in them, press cancel and select the Typical Settings option. You can easily change these values later.
9. In the Workgroup or Domain window enter the name of your workgroup or domain.
· A workgroup is a small group of computers on a network that enables users to work together and does not support centralized administration.
· A domain is a logical grouping of computers on a network that has a central security database for storing security information. Centralized security and administration are important for computers in a domain because they enable an administrator to easily manage computers that are geographically distant from each other. A domain is administered as a unit with common rules and procedures. Each domain has a unique name, and each computer within a domain has a unique name.
If you're a stand-alone computer, or if you don't know what to enter, or if you don't have the sufficient rights to join a domain - leave the default entry selected and press Next.
If you want to join a domain (NT 4.0 domain of W2K/2003 Active Directory domain) enter the domain's name in the "Yes, make this computer a member of the following domain" box.
To successfully join a domain you need the following:
· The person performing the installation must have a user account in Active Directory. This account does not need to be the domain Administrator account.
and
· The computer must have an existing computer account in the Active Directory database of the domain that the computer is joining, and the computer must be named exactly as its domain account is named.
or
· The person performing the installation must have appropriate permission to create a domain account for the computer during installation.
Also, you need to have connectivity to the domain's domain controllers (only to the PDC if on an NT 4.0 domain) and a fully functional DNS server (only in AD domains). Read the Joining a Domain in Windows XP Pro and Requirements when Joining a Domain pages for more on this issue.
Enter the Active Directory domain name (in the form of xxx.yyy, for example: DPETRI.NET) or the NetBIOS name of the NT 4.0 domain (in the form of xxx, for example: DPETRI). Press Next.
Note: If you provide a wrong domain name or do not have the correct connectivity to the domain's DNS server you will get an error message.
A username/password window will appear. Enter the name and password of the domain's administrator (or your own if you're the administrator on the target domain).
Note: Providing a wrong username or password will cause this phase to fail.
10. Next the setup process will finish copying files and configuring the setup. You do not need to do anything.
11. After the copying and configuring phase is finished, if Windows Server 2003 finds that you have a badly configured screen resolution it will advise you to change it and ask you if you see the new settings right.
BTW, the minimum supported screen resolution in 2003 is 800X600.
12. Setup finishes and boots Windows Server 2003.
15. That's it! you're done!
Wednesday, November 26, 2008
Tuesday, November 25, 2008
Visual display unit
Main article: Visual display unit
An LG flat-panel LCD monitor.
A visual display unit (also called monitor) is a piece of electrical equipment, usually separate from the computer case, which displays viewable images generated by a computer without producing a permanent record. The word "monitor" is used in other contexts; in particular in television broadcasting, where atelevision picture is displayed to a high standard. A computer display device is usually either a cathode ray tube or some form of flat panel such as a TFT LCD. The monitor comprises the display device, circuitry to generate a picture from electronic signals sent by the computer, and an enclosure or case. Within the computer, either as an integral part or a plugged-in interface, there is circuitry to convert internal data to a format compatible with a monitor. The images from monitors originally contained only text, but as Graphical user interfaces emerged and became common, they began to display more images and multimedia content.
[edit]Keyboards
Computer keyboard
In computing, a keyboard is an arrangement of buttons that each correspond to a function, letter, or number. They are the primary devices of inputing text. In most cases, they contain an aray of keys specifically organized with the corresponding letters, numbers, and functions printed or engraved on the button. They are generally designed around an operators language, and many different versions for different languages exist. In English, the most common layout is the QWERTY layout, which was originally used intypewriters. They have evolved over time, and have been modified for use in computers with the addition of function keys, number keys, arrow keys, and OS specific keys. Often, specific functions can be achieved by pressing multiple keys at once or in succession, such as inputing characters with accents or opening a task manager. Programs use keyboard shotcuts very differently and all use different keyboard shortcuts for different program specific operations, such as refreshing a web page in a web browser or selecting all text in a word processor.
[edit]Pointing devices
Apple Mighty Mouse that detects the location of your finger, when clicking, withCapacitive sensors.
A Mouse on a computer is a small, slidable device that users hold and slide around to point at, click, and sometimes drag objects on screen in a graphical user interface using a pointer on screen. Almost all Personal Computers have mice. It may be plugged into a computer's rear mouse socket, or as a USB device, or, more recently, may be connected wirelessly via a USB antenna or Bluetooth antenna. In the past, they had a single button that users could press down on the device to "click" on whatever the pointer on the screen was hovering over. Now, however, many Mice have two or three buttons; a "right click" function button on the mouse, which performs a secondary action on a selected object, and a scroll wheel, which users can rotate the wheel using their fingers to "scroll" up or down. The scroll wheel can also be pressed down, and therefore be used as a third button. Different programs make use of these functions differently, and may scroll horizontally by default with the scroll wheel, open different menus with different buttons, among others.
Mice traditionally detected movement and communicated with the computer with an internal "mouse ball"; and use optical encoders to detect rotation of the ball and tell the computer where the mouse has moved. However, these systems were subject to low durability and accuracy. Modern mice use optical technology to directly trace movement of the surface under the mouse and are much more accurate and durable. They work on a wider variety of surfaces and can even operate on walls, ceilings or other non-horizontal surfaces.
[edit]Other components
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You can help by converting this section to prose, if appropriate. Editing help is available. (October 2007)
Mass storage
All computers require either fixed or removable storage for their operating system, programs and user generated material.
Formerly the 5 1/4 inch and 3 1/2 inch floppy drive were the principal forms of removable storage for backup of user files and distribution of software.
As memory sizes increased, the capacity of the floppy did not keep pace; the Zip drive and other higher-capacity removable media were introduced but never became as prevalent as the floppy drive.
By the late 1990s the optical drive, in CD and later DVD and Blu-ray Disc, became the main method for software distribution, and writeable media provided backup and file interchange. Floppy drives have become uncommon in desktop personal computers since about 2000, and were dropped from many laptop systems even earlier. [11]
Early home computers used compact audio cassettes for file storage; these were at the time a very low cost storage solution, but were displaced by floppy disk drives when manfacturing costs dropped, by the mid 1980s.
A second generation of tape recorders was provided when Videocassette recorders were pressed into service as backup media for larger disk drives. All these systems were less reliable and slower than purpose-built magnetic tape drives. Such tape drives were uncommon in consumer-type personal computers but were a necessity in business or industrial use.
Interchange of data such as photographs from digital cameras is greatly expedited by installation of a card reader, which often is compatible with several forms of flash memory. It is usually faster and more convenient to move large amounts of data by removing the card from the mobile device, instead of communicating with the mobile device through a USB interface.
A USB flash drive today performs much of the data transfer and backup functions formerly done with floppy drives, Zip disks and other devices. Main-stream current operating systems for personal computers provide standard support for flash drives, allowing interchange even between computers using different processors and operating systems. The compact size and lack of moving parts or dirt-sensitive media, combined with low cost for high capacity, have made flash drives a popular and useful accessory for any personal computer user.
The operating system (e.g.: Microsoft Windows, Mac OS, Linux or many others) can be located on any removable storage, but typically it is on one of the hard disks. A Live CD is also possible, but it is very slow and is usually used for installation of the OS, demonstrations, or problem solving. Flash-based memory is currently expensive (as of mid-2008) but is starting to appear in laptop computers because of its low weight and low energy consumption, compared to hard disk storage.
Computer communications
Internal modem card
Modem
Network adapter card
Router
Common peripherals and adapter cards
Headset
Joystick
Microphone
Printer
Scanner
Sound adapter card as a separate card rather than located on the motherboard
Speakers
Webcam
[edit]Software
Main article: Computer software
A screenshot of theOpenOffice.org Writer software
Computer software is a general term used to describe a collection of computer programs, procedures and documentation that perform some tasks on a computer system.[12] The term includes application softwaresuch as word processors which perform productive tasks for users, system software such as operating systems, which interface with hardware to provide the necessary services for application software, andmiddleware which controls and co-ordinates distributed systems.
Software applications for word processing, Internet browsing, Internet faxing, e-mail and other digital messaging, multimedia playback, computer game play and computer programming are common. The user of a modern personal computer may have significant knowledge of the operating environment and application programs, but is not necessarily interested in programming nor even able to write programs for the computer. Therefore, most software written primarily for personal computers tends to be designed with simplicity of use, or "user-friendliness" in mind. However, the software industry continuously provide a wide range of new products for use in personal computers, targeted at both the expert and the non-expert user.
[edit]Operating system
Main article: Operating system
KDE 4 running on a Linuxdistribution.
An operating system (OS) manages computer resources and provides programmers with an interface used to access those resources. An operating system processes system data and user input, and responds by allocating and managing tasks and internal system resources as a service to users and programs of the system. An operating system performs basic tasks such as controlling and allocating memory, prioritizing system requests, controlling input and output devices, facilitating computer networking and managing files.
Common contemporary desktop OSes are Linux, Mac OS X, Microsoft Windows, Solaris and PC-BSD. Mac, Linux, and Windows all have server and personal variants. With the exception of Microsoft Windows, the designs of each of the aforementioned OSs were inspired by, or directly inherited from, the Unixoperating system. Unix was developed at Bell Labs beginning in the late 1960s and spawned the development of numerous free and proprietary operating systems.
Operating systems that can be found on mobile devices include Palm OS, Windows Mobile, Familiar Linux, The Ångström Distribution and Darwin (iPhone OS).
[edit]Microsoft Windows
Main article: Microsoft Windows
Microsoft Windows is the name of several families of software operating systems by Microsoft. Microsoft first introduced an operating environment named Windows in November 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces(GUIs).[13][14] The most recent client version of Windows is Windows Vista. The current server version of Windows is Windows Server 2008.
[edit]Linux
Main article: Linux
A KDE Linux desktop
Linux is a family of Unix-like computer operating systems. Linux is one of the most prominent examples offree software and open source development: typically all underlying source code can be freely modified, used, and redistributed by anyone.[15] The name "Linux" comes from the Linux kernel, started in 1991 byLinus Torvalds. The system's utilities and libraries usually come from the GNU operating system, announced in 1983 by Richard Stallman. The GNU contribution is the basis for the alternative nameGNU/Linux.[16]
Predominantly known for its use in servers, Linux is supported by corporations such as Dell, Hewlett-Packard, IBM, Novell, Oracle Corporation, Red Hat, and Sun Microsystems. It is used as an operating system for a wide variety of computer hardware, including desktop computers, supercomputers,[17] video game systems, such as the PlayStation 3, several arcade games, and embedded devices such as mobile phones, routers, and stage lighting systems.
[edit]Mac OS X
Main article: Mac OS X
Mac OS X desktop
Mac OS X is a line of graphical operating systems developed, marketed, and sold by Apple Inc., the latest of which is pre-loaded on all currently shipping under Macintosh series of personal computers. Mac OS X is the successor to the original Mac OS, which had been Apple's primary operating system since 1984. Unlike its predecessors, Mac OS X is a Unix-based operating system[18] built on technology developed atNeXT from the second half of the 1980s until early 1997, when Apple purchased the company.
The server edition, Mac OS X Server, is architecturally very similar to its desktop counterpart but usually runs on Apple's line of Macintosh server hardware. It includes workgroup management and administration software tools that provide simplified access to key network services, including a mail transfer agent, aSamba server, an LDAP server, a domain name server, and others.
[edit]Applications
This section does not cite any references or sources.
Please help improve this section by adding citations to reliable sources. Unverifiable material may be challenged and removed. (June 2008)
Main article: Application software
GIMP raster graphics editor
Application software employs the capabilities of a computer directly and thoroughly to a task that the user wishes to perform. This should be contrasted with system software which is involved in integrating a computer's various capabilities, but typically does not directly apply them in the performance of tasks that benefit the user. In this context the term application refers to both the application software and its implementation. A simple, if imperfect analogy in the world of hardware would be the relationship of an electric light bulb (an application) to an electric power generation plant (a system). The power plant merely generates electricity, not itself of any real use until harnessed to an application like the electric light that performs a service that benefits the user.
Typical examples of software applications are word processors, spreadsheets, and media players. Multiple applications bundled together as a package are sometimes referred to as an application suite. Microsoft Office and OpenOffice.org, which bundle together a word processor, a spreadsheet, and several other discrete applications, are typical examples. The separate applications in a suite usually have a user interface that has some commonality making it easier for the user to learn and use each application. And often they may have some capability to interact with each other in ways beneficial to the user. For example, a spreadsheet might be able to be embedded in a word processor document even though it had been created in the separate spreadsheet application.
End-user development tailors systems to meet the user's specific needs. User-written software include spreadsheet templates, word processor macros, scientific simulations, graphics and animation scripts. Even email filters are a kind of user software. Users create this software themselves and often overlook how important it is.
[edit]Lifetime
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Most personal computers are standardized to the point that purchased software is expected to run with little or no customization for the particular computer. Many PCs are also user-upgradeable, especially desktop and workstation class computers. Devices such as main memory, mass storage, even the motherboard and central processing unit may be easily replaced by an end user. This upgradeability is, however, not indefinite due to rapid changes in the personal computer industry. A PC that was considered top-of-the-line five or six years prior may be impractical to upgrade due to changes in industry standards. Such a computer usually must be totally replaced once it is no longer suitable for its purpose. This upgrade and replacement cycle is partially related to new releases of the primary mass-market operating system, which tends to drive the acquisition of new hardware and render obsolete previously serviceable hardware (planned obsolescence).
[edit]See also
Electronics portal
Look up Personal computer in
Wiktionary, the free dictionary.
Wikiquote has a collection of quotations related to:
Personal computer
Wikimedia Commons has media related to:
Personal computer
At Wikiversity, you can learn about: Introduction to Computers/Personal
Desktop computer
Desktop replacement computer
Gaming PC
List of computer system manufacturers
Personal Computer Museum
Public computer
Quiet PC
Supercomputer
An exploded view of a modern personal computer and peripherals:
Scanner
CPU (Microprocessor)
Primary storage (RAM)
Expansion cards (graphics cards, etc)
Power supply
Optical disc drive
Secondary storage (Hard disk)
Motherboard
Speakers
Monitor
System software
Application software
Keyboard
Mouse
External hard disk
Printer
Main article: Computer hardware
Posted by shehand at 2:39 AM 0 comments
Main article: Desktop computer
Dell OptiPlex desktop computer
Prior to the wide spread of PCs a computer that could fit on a desk was considered remarkably small. Today the phrase usually indicates a particular style of computer case. Desktop computers come in a variety of styles ranging from large vertical tower cases to small form factor models that can be tucked behind an LCD monitor. In this sense, the term 'desktop' refers specifically to a horizontally-oriented case, usually intended to have the display screen placed on top to save space on the desk top. Most modern desktop computers have separate screens and keyboards.
[edit]Nettop
Main article: Nettop (computer)
A subtype of desktops, called nettops, was introduced by Intel in February 2008 to describe low-cost, lean-function, desktop computers. A similar subtype of laptops (or notebooks) are the netbooks (see below).
[edit]Laptop
Main article: Laptop
A modern mid-range HP Laptop.
A laptop computer or simply laptop, also called a notebook computer or sometimes a notebook, is a small personal computer designed for mobility. Usually all of the interface hardware needed to operate the laptop, such as parallel and serial ports, graphics card, sound channel, etc., are built in to a single unit. Most laptops contain batteries to facilitate operation without a readily available electrical outlet. In the interest of saving power, weight and space, they usually share RAM with the video channel, slowing their performance compared to an equivalent desktop machine.
One main drawback of the laptop is that, due to the size and configuration of components, relatively little can be done to upgrade the overall computer from its original design. Some devices can be attached externally through ports (including via USB), however internal upgrades are not recommended or in some cases impossible, making the desktop PC more modular.
A subtype of notebooks, called subnotebooks, are computers with most of the features of a standard laptop computer but smaller. They are larger than hand-held computers, and usually run full versions of desktop/laptop operating systems. Ultra-Mobile PCs (UMPC) are usually considered subnotebooks, or more specifically, subnotebook Tablet PCs (see below). Netbooks are sometimes considered in this category, though they are sometimes separated in a category of their own (see below).
Desktop replacements, meanwhile, are large laptops meant to replace a desktop computer while keeping the mobility of a laptop.
[edit]Netbook
Main article: Netbook
Black ASUS Eee PC in proportions comparison with tissues
Netbook PCs are small portable computers in a "clamshell" design, that are designed specifically for wireless communication and access to the Internet. They are generally much lighter and cheaper thansubnotebooks, and have a smaller display, between 7" and 9", with a screen resolution between 800x600 and 1024x768. The operating systems and applications on them are usually specially modified so they can be comfortably used with a smaller sized screen, and the OS is often based on Linux, although some Netbooks also use Windows XP. Some Netbooks make use of their built in high speed Wireless connectivity to offload some of their applications software to Internet servers, through the principle of Cloud computing, as most Netbooks have small solid state storage systems instead of hard-disks. Storage capacities are usually in the 4 to 16 GB range. One of the first examples of such a system was the originalEEE PC.
[edit]Tablet PC
Main article: Tablet PC
HP Compaq tablet PC with rotating/removable keyboard.
A tablet PC is a notebook or slate-shaped mobile computer, first introduced by Pen computing in the early 90s with their PenGo Tablet Computer and popularized by Microsoft. Its touchscreen or graphics tablet/screen hybrid technology allows the user to operate the computer with a stylus or digital pen, or a fingertip, instead of a keyboard or mouse. The form factor offers a more mobile way to interact with a computer. Tablet PCs are often used where normal notebooks are impractical or unwieldy, or do not provide the needed functionality.
[edit]Ultra-Mobile PC
Main article: Ultra-Mobile PC
Samsung Q1 Ultra-Mobile PC.
The ultra-mobile PC (UMPC) is a specification for a small form factortablet PC. It was developed as a joint development exercise byMicrosoft, Intel, and Samsung, among others. Current UMPCs typically feature the Windows XP Tablet PC Edition 2005, Windows Vista Home Premium Edition, or Linux operating system and low-voltage Intel Pentium or VIA C7-M processors in the 1GHz range.
[edit]Home Theater PC
Main article: Home theater PC
Antec Fusion V2 home theater PC with keyboard on top.
A home theater PC (HTPC) is a convergence device that combines the functions of a personal computer and a digital video recorder. It is connected to a television or a television-sized computer display and is often used as a digital photo, music, video player, TV receiver and digital video recorder. Home theater PCs are also referred to as media center systems or media servers. The general goal in a HTPC is usually to combine many or all components of a home theater setup into one box. They can be purchased pre-configured with the required hardware and software needed to add television programming to the PC, or can be cobbled together out of discrete components as is commonly done with Windows Media Center, GB-PVR, SageTV, Famulent or LinuxMCE.
[edit]Pocket PC
Main article: Pocket PC
An O2 pocket PC
A pocket PC is a hardware specification for a handheld-sized computer (personal digital assistant) that runs theMicrosoft Windows Mobile operating system. It may have the capability to run an alternative operating system likeNetBSD or Linux. It has many of the capabilities of modern desktop PCs.
Currently there are tens of thousands of applications for handhelds adhering to the Microsoft Pocket PC specification, many of which are freeware. Some of these devices also include mobile phone features. Microsoft compliant Pocket PCs can also be used with many other add-ons like GPS receivers, barcode readers, RFID readers, and cameras. In 2007, with the release of Windows Mobile 6, Microsoft dropped the name Pocket PC in favor of a new naming scheme. Devices without an integrated phone are called Windows Mobile Classic instead of Pocket PC. Devices with an integrated phone and a touch screen are called Windows Mobile Professional.[9]
Posted by shehand at 2:38 AM 0 comments
Market
Market
In 2001 125 million personal computers were shipped in comparison to 48 thousand in 1977. More than 500 million PCs were in use in 2002 and one billion personal computers had been sold worldwide since mid-1970s till this time. Of the latter figure, 75 percent were professional or work related, while the rest sold for personal or home use. About 81.5 percent of PCs shipped had been desktop computers, 16.4 percentlaptops and 2.1 percent servers. United States had received 38.8 percent (394 million) of the computers shipped, Europe 25 percent and 11.7 percent had gone to Asia-Pacific region, the fastest-growing market as of 2002. The second billion was expected to be sold by 2008.[2] Almost half of all the households in Western Europe had a personal computer and a computer could be found in 40 percent of homes in United Kingdom, compared with only 13 percent in 1985.[3]
As of June 2008, the number of personal computers in use worldwide hit one billion, while another billion is expected to be reached by 2014. Mature markets like the United States, Western Europe and Japan accounted for 58 percent of the worldwide installed PCs. The emerging markets were expected to double their installed PCs by 2013 and to take 70 percent of the second billion PCs. About 180 million PCs (16 percent of the existing installed base) were expected to be replaced and 35 million to be dumped into landfill in 2008. The whole installed base grew 12 percent annually.[4][5]
[edit]Rugged computer industry
Besides the regular computer manufacturers, companies making especially rugged versions of computers have sprung up, offering alternatives for people operating their machines in extreme weather or environments. [6]
[edit]Netbooks and nettops
The emergence of new market segment of small, energy-efficient and low-cost devices (netbooks and nettops) could threaten established companies like Microsoft, Intel, HP or Dell, analysts said in July 2008. A market research firm International Data Corporation predicted that the category could grow from fewer than 500,000 in 2007 to 9 million in 2012 as the market for low cost and secondhand computers expands in developed economies. [7] Also, after Microsoft ceased selling of Windows XP for ordinary machines, it made an exception and continued to offer the operating system for netbook and nettop makers.[8]
Posted by shehand at 2:38 AM 0 comments
History of personal computers
ain article: History of personal computers
IBM 5150 as of 1981
The capabilities of the PC have changed greatly since the introduction of electronic computers. By the early 1970s, people in academic or research institutions had the opportunity for single-person use of a computer system in interactive mode for extended durations, although these systems would still have been too expensive to be owned by a single person. The introduction of the microprocessor, a single chip with all the circuitry that formerly occupied large cabinets, led to the proliferation of personal computers after about 1975. Early personal computers - generally called microcomputers - were sold often in Electronic kit form and in limited volumes, and were of interest mostly to hobbyists and technicians. Minimal programming was done by toggle switches, and output was provided by front panel indicators. Practical use required peripherals such as keyboards, computer terminals, disk drives, and printers. By 1977, mass-market pre-assembled computers allowed a wider range of people to use computers, focusing more on software applications and less on development of the processor hardware.
Throughout the late 1970s and into the 1980s, computers were developed for household use, offering personal productivity, programming and games. Somewhat larger and more expensive systems (although still low-cost compared with minicomputers and mainframes) were aimed for office and small business use. Workstations are characterized by high-performance processors and graphics displays, with large local disk storage, networking capability, and running under a multitasking operating system. Workstations are still used for tasks such as computer-aided design, drafting and modelling, computation-intensive scientific and engineering calculations, image processing, architectural modelling, and computer graphics for animation and motion picture visual effects.[1]
Eventually the market segments lost any technical distinction; business computers acquired color graphics capability and sound, and home computers and game systems users used the same processors and operating systems as office workers. Mass-market computers had graphics capabilities and memory comparable to dedicated workstations of a few years before. Even local area networking, originally a way to allow business computers to share expensive mass storage and peripherals, became a standard feature of the personal computers used at home.
Posted by shehand at 2:36 AM 0 comments
Tuesday, November 11, 2008
How Amazon Works
n 1995, Amazon.com sold its first book, which shipped from Jeff Bezos' garage in Seattle. In 2006, Amazon.com sells a lot more than books and has sites serving seven countries, with 21 fulfillment centers around the globe totaling more than 9 million square feet of warehouse space.
The story is an e-commerce dream, and Jeff Bezos was Time magazine's Person of the Year in 1999. The innovation and business savvy that sustains Amazon.com is legendary and, at times, controversial: The company owns dozens of patents on e-commerce processes that some argue should remain in the public domain. In this article, we'll find out what Amazon does, what makes it different from other e-commerce Web sites and how its technology infrastructure supports its multi-pronged approach to online sales.
Amazon.com Basics
Amazon.com sells lots and lots of stuff. The direct Amazon-to-buyer sales approach is really no different from what happens at most other large, online retailers except for its range of products. You can find beauty supplies, clothing, jewelry, gourmet food, sporting goods, pet supplies, books, CDs, DVDs,computers, furniture, toys, garden supplies, bedding and almost anything else you might want to buy. What makes Amazon a giant is in the details. Besides its tremendous product range, Amazon makes every possible attempt to customize the buyer experience.
When you arrive at the homepage, you'll find not only special offers and featured products, but if you've been to Amazon.com before, you'll also find some recommendations just for you. Amazon knows you by name and tries to be your personal shopper.
Courtesy Amazon.com
The embedded marketing techniques that Amazon employs to personalize your experience are probably the best example of the company's overall approach to sales: Know your customer very, very well.Customer tracking is an Amazon stronghold. If you let the Web site stick a cookie on your hard drive, you'll find yourself on the receiving end of all sorts of useful features that make your shopping experience pretty cool, like recommendations based on past purchases and lists of reviews and guides written by users who purchased the products you're looking at.
The other main feature that puts Amazon.com on another level is the multi-leveled e-commercestrategy it employs. Amazon.com lets almost anyone sell almost anything using its platform. You can find straight sales of merchandise sold directly by Amazon, like the books it sold back in the mid-'90s out of Jeff Bezos' garage -- only now they're shipped from a very big warehouse. Since 2000, you can also find goods listed by third-party sellers -- individuals, small companies and retailers like Target and Toys 'R Us. You can find used goods, refurbished goods and auctions. You could say that Amazon is simply the ultimate hub for selling merchandise on the Web, except that the company has recently added a more extroverted angle to its strategy.
Online Commerce
eBay
Electronic Payment
Can Facebook make you rich?
In addition to the affiliate program that lets anybody post Amazon links earn a commission on click-through sales, there's now a program that lets those affiliates (Amazon calls them "associates") build entire Web sites based on Amazon's platform. They can literally create mini Amazon Web sites if they want to, building on Amazon's huge database of products and applications for their own purposes. As long as any purchases go through Amazon, you can build a site called Amazonish.com, pull products directly from Amazon's servers, write your own guides and recommendations and earn a cut of any sales. Amazon has become a software developer's playground.
Before we dig deeper into Amazon's e-commerce methods, let's take a quick look at the technolo
Posted by shehand at 2:36 AM 0 comments
How does satellite Internet operate?
How do you access the Internet other than dial-up if you live too far from a phone company office for DSL and there is no cable TV on your street? Satellite Internet access may be worth considering. It's ideal for rural Internetusers who want broadband access. Satellite Internet does not use telephonelines or cable systems, but instead uses a satellite dish for two-way (upload and download) data communications. Upload speed is about one-tenth of the 500 kbps download speed. Cable and DSL have higher download speeds, but satellite systems are about 10 times faster than a normal modem.
Firms that offer or plan to offer two-way satellite Internet include StarBand, Pegasus Express, Teledesic and Tachyon. Tachyon service is available today in the United States, Western Europe and Mexico. Pegasus Express is the two-way version of DirecPC.
Two-way satellite Internet consists of:
Approximately a two-foot by three-foot dish
Two modems (uplink and downlink)
Coaxial cables between dish and modem
The key installation planning requirement is a clear view to the south, since the orbiting satellites are over the equator area. And, like satellite TV, trees and heavy rains can affect reception of the Internet signals.
Two-way satellite Internet uses Internet Protocol (IP) multicasting technology, which means up to 5,000 channels of communication can simultaneously be served by a single satellite. IP multicasting sends data from one point to many points (at the same time) by sending data in compressed format. Compression reduces the size of the data and the bandwidth. Usual dial-up land-based terrestrial systems have bandwidth limitations that prevent multicasting of this magnitude.
Graphic courtesy of StarBand
StarBand's System
Some satellite-Internet service still requires you to have a dial-up or cable modem connection for the data you send to the Internet. The satellite data downlink is just like the usual terrestrial link, except the satellite transmits the data to your computer via the same dish that would allow you to receive a Pay-Per-View television program.
So, if you are in a rural area and you want broadband access to the Internet, satellite Internet may be for you!
Posted by shehand at 2:30 AM 0 comments
How RAM Works
Memory Modules
The type of board and connector used for RAM in desktop computers has evolved over the past few years. The first types were proprietary, meaning that different computer manufacturers developed memory boards that would only work with their specific systems. Then came SIMM, which stands for single in-line memory module. This memory board used a 30-pin connector and was about 3.5 x .75 inches in size (about 9 x 2 cm). In most computers, you had to install SIMMs in pairs of equal capacity and speed. This is because the width of the bus is more than a single SIMM. For example, you would install two 8-megabyte (MB) SIMMs to get 16 megabytes total RAM. Each SIMM could send 8 bits of data at one time, while the system bus could handle 16 bits at a time. Later SIMM boards, slightly larger at 4.25 x 1 inch (about 11 x 2.5 cm), used a 72-pin connector for increased bandwidth and allowed for up to 256 MB of RAM.
From the top: SIMM, DIMM and SODIMM memory modules
As processors grew in speed and bandwidth capability, the industry adopted a new standard in dual in-line memory module (DIMM). With a whopping 168-pin or 184-pin connector and a size of 5.4 x 1 inch (about 14 x 2.5 cm), DIMMs range in capacity from 8 MB to 1 GB per module and can be installed singly instead of in pairs. Most PC memory modules and the modules for the Mac G5 systems operate at 2.5 volts, while older Mac G4 systems typically use 3.3 volts. Another standard, Rambus in-line memory module (RIMM), is comparable in size and pin configuration to DIMM but uses a special memory bus to greatly increase speed.
Many brands of notebook computers use proprietary memory modules, but several manufacturers use RAM based on the small outline dual in-line memory module (SODIMM) configuration. SODIMM cards are small, about 2 x 1 inch (5 x 2.5 cm), and have 144 or 200 pins. Capacity ranges from 16 MB to 1 GB per module. To conserve space, the Apple iMac desktop computer uses SODIMMs instead of the traditional DIMMs. Sub-notebook computers use even smaller DIMMs, known as MicroDIMMs, which have either 144 pins or 172 pins.
Most memory available today is highly reliable. Most systems simply have the memory controller check for errors at start-up and rely on that. Memory chips with built-in error-checking typically use a method known as parity to check for errors. Parity chips have an extra bit for every 8 bits of data. The way parity works is simple. Let's look at even parity first.
When the 8 bits in a byte receive data, the chip adds up the total number of 1s. If the total number of 1s is odd, the parity bit is set to 1. If the total is even, the parity bit is set to 0. When the data is read back out of the bits, the total is added up again and compared to the parity bit. If the total is odd and the parity bit is 1, then the data is assumed to be valid and is sent to the CPU. But if the total is odd and the parity bit is 0, the chip knows that there is an error somewhere in the 8 bits and dumps the data. Odd parity works the same way, but the parity bit is set to 1 when the total number of 1s in the byte are even.
The problem with parity is that it discovers errors but does nothing to correct them. If a byte of data does not match its parity bit, then the data are discarded and the system tries again. Computers in critical positions need a higher level of fault tolerance. High-end servers often have a form of error-checking known as error-correction code (ECC). Like parity, ECC uses additional bits to monitor the data in each byte. The difference is that ECC uses several bits for error checking -- how many depends on the width of the bus -- instead of one. ECC memory uses a special algorithm not only to detect single bit errors, but actually correct them as well. ECC memory will also detect instances when more than one bit of data in a byte fails. Such failures are very rare, and they are not correctable, even with ECC.
The majority of computers sold today use nonparity memory chips. These chips do not provide any type of built-in error checking, but instead rely on the memory controller for error detection.
Posted by shehand at 1:44 AM 0 comments
Older Posts
An LG flat-panel LCD monitor.
A visual display unit (also called monitor) is a piece of electrical equipment, usually separate from the computer case, which displays viewable images generated by a computer without producing a permanent record. The word "monitor" is used in other contexts; in particular in television broadcasting, where atelevision picture is displayed to a high standard. A computer display device is usually either a cathode ray tube or some form of flat panel such as a TFT LCD. The monitor comprises the display device, circuitry to generate a picture from electronic signals sent by the computer, and an enclosure or case. Within the computer, either as an integral part or a plugged-in interface, there is circuitry to convert internal data to a format compatible with a monitor. The images from monitors originally contained only text, but as Graphical user interfaces emerged and became common, they began to display more images and multimedia content.
[edit]Keyboards
Computer keyboard
In computing, a keyboard is an arrangement of buttons that each correspond to a function, letter, or number. They are the primary devices of inputing text. In most cases, they contain an aray of keys specifically organized with the corresponding letters, numbers, and functions printed or engraved on the button. They are generally designed around an operators language, and many different versions for different languages exist. In English, the most common layout is the QWERTY layout, which was originally used intypewriters. They have evolved over time, and have been modified for use in computers with the addition of function keys, number keys, arrow keys, and OS specific keys. Often, specific functions can be achieved by pressing multiple keys at once or in succession, such as inputing characters with accents or opening a task manager. Programs use keyboard shotcuts very differently and all use different keyboard shortcuts for different program specific operations, such as refreshing a web page in a web browser or selecting all text in a word processor.
[edit]Pointing devices
Apple Mighty Mouse that detects the location of your finger, when clicking, withCapacitive sensors.
A Mouse on a computer is a small, slidable device that users hold and slide around to point at, click, and sometimes drag objects on screen in a graphical user interface using a pointer on screen. Almost all Personal Computers have mice. It may be plugged into a computer's rear mouse socket, or as a USB device, or, more recently, may be connected wirelessly via a USB antenna or Bluetooth antenna. In the past, they had a single button that users could press down on the device to "click" on whatever the pointer on the screen was hovering over. Now, however, many Mice have two or three buttons; a "right click" function button on the mouse, which performs a secondary action on a selected object, and a scroll wheel, which users can rotate the wheel using their fingers to "scroll" up or down. The scroll wheel can also be pressed down, and therefore be used as a third button. Different programs make use of these functions differently, and may scroll horizontally by default with the scroll wheel, open different menus with different buttons, among others.
Mice traditionally detected movement and communicated with the computer with an internal "mouse ball"; and use optical encoders to detect rotation of the ball and tell the computer where the mouse has moved. However, these systems were subject to low durability and accuracy. Modern mice use optical technology to directly trace movement of the surface under the mouse and are much more accurate and durable. They work on a wider variety of surfaces and can even operate on walls, ceilings or other non-horizontal surfaces.
[edit]Other components
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You can help by converting this section to prose, if appropriate. Editing help is available. (October 2007)
Mass storage
All computers require either fixed or removable storage for their operating system, programs and user generated material.
Formerly the 5 1/4 inch and 3 1/2 inch floppy drive were the principal forms of removable storage for backup of user files and distribution of software.
As memory sizes increased, the capacity of the floppy did not keep pace; the Zip drive and other higher-capacity removable media were introduced but never became as prevalent as the floppy drive.
By the late 1990s the optical drive, in CD and later DVD and Blu-ray Disc, became the main method for software distribution, and writeable media provided backup and file interchange. Floppy drives have become uncommon in desktop personal computers since about 2000, and were dropped from many laptop systems even earlier. [11]
Early home computers used compact audio cassettes for file storage; these were at the time a very low cost storage solution, but were displaced by floppy disk drives when manfacturing costs dropped, by the mid 1980s.
A second generation of tape recorders was provided when Videocassette recorders were pressed into service as backup media for larger disk drives. All these systems were less reliable and slower than purpose-built magnetic tape drives. Such tape drives were uncommon in consumer-type personal computers but were a necessity in business or industrial use.
Interchange of data such as photographs from digital cameras is greatly expedited by installation of a card reader, which often is compatible with several forms of flash memory. It is usually faster and more convenient to move large amounts of data by removing the card from the mobile device, instead of communicating with the mobile device through a USB interface.
A USB flash drive today performs much of the data transfer and backup functions formerly done with floppy drives, Zip disks and other devices. Main-stream current operating systems for personal computers provide standard support for flash drives, allowing interchange even between computers using different processors and operating systems. The compact size and lack of moving parts or dirt-sensitive media, combined with low cost for high capacity, have made flash drives a popular and useful accessory for any personal computer user.
The operating system (e.g.: Microsoft Windows, Mac OS, Linux or many others) can be located on any removable storage, but typically it is on one of the hard disks. A Live CD is also possible, but it is very slow and is usually used for installation of the OS, demonstrations, or problem solving. Flash-based memory is currently expensive (as of mid-2008) but is starting to appear in laptop computers because of its low weight and low energy consumption, compared to hard disk storage.
Computer communications
Internal modem card
Modem
Network adapter card
Router
Common peripherals and adapter cards
Headset
Joystick
Microphone
Printer
Scanner
Sound adapter card as a separate card rather than located on the motherboard
Speakers
Webcam
[edit]Software
Main article: Computer software
A screenshot of theOpenOffice.org Writer software
Computer software is a general term used to describe a collection of computer programs, procedures and documentation that perform some tasks on a computer system.[12] The term includes application softwaresuch as word processors which perform productive tasks for users, system software such as operating systems, which interface with hardware to provide the necessary services for application software, andmiddleware which controls and co-ordinates distributed systems.
Software applications for word processing, Internet browsing, Internet faxing, e-mail and other digital messaging, multimedia playback, computer game play and computer programming are common. The user of a modern personal computer may have significant knowledge of the operating environment and application programs, but is not necessarily interested in programming nor even able to write programs for the computer. Therefore, most software written primarily for personal computers tends to be designed with simplicity of use, or "user-friendliness" in mind. However, the software industry continuously provide a wide range of new products for use in personal computers, targeted at both the expert and the non-expert user.
[edit]Operating system
Main article: Operating system
KDE 4 running on a Linuxdistribution.
An operating system (OS) manages computer resources and provides programmers with an interface used to access those resources. An operating system processes system data and user input, and responds by allocating and managing tasks and internal system resources as a service to users and programs of the system. An operating system performs basic tasks such as controlling and allocating memory, prioritizing system requests, controlling input and output devices, facilitating computer networking and managing files.
Common contemporary desktop OSes are Linux, Mac OS X, Microsoft Windows, Solaris and PC-BSD. Mac, Linux, and Windows all have server and personal variants. With the exception of Microsoft Windows, the designs of each of the aforementioned OSs were inspired by, or directly inherited from, the Unixoperating system. Unix was developed at Bell Labs beginning in the late 1960s and spawned the development of numerous free and proprietary operating systems.
Operating systems that can be found on mobile devices include Palm OS, Windows Mobile, Familiar Linux, The Ångström Distribution and Darwin (iPhone OS).
[edit]Microsoft Windows
Main article: Microsoft Windows
Microsoft Windows is the name of several families of software operating systems by Microsoft. Microsoft first introduced an operating environment named Windows in November 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces(GUIs).[13][14] The most recent client version of Windows is Windows Vista. The current server version of Windows is Windows Server 2008.
[edit]Linux
Main article: Linux
A KDE Linux desktop
Linux is a family of Unix-like computer operating systems. Linux is one of the most prominent examples offree software and open source development: typically all underlying source code can be freely modified, used, and redistributed by anyone.[15] The name "Linux" comes from the Linux kernel, started in 1991 byLinus Torvalds. The system's utilities and libraries usually come from the GNU operating system, announced in 1983 by Richard Stallman. The GNU contribution is the basis for the alternative nameGNU/Linux.[16]
Predominantly known for its use in servers, Linux is supported by corporations such as Dell, Hewlett-Packard, IBM, Novell, Oracle Corporation, Red Hat, and Sun Microsystems. It is used as an operating system for a wide variety of computer hardware, including desktop computers, supercomputers,[17] video game systems, such as the PlayStation 3, several arcade games, and embedded devices such as mobile phones, routers, and stage lighting systems.
[edit]Mac OS X
Main article: Mac OS X
Mac OS X desktop
Mac OS X is a line of graphical operating systems developed, marketed, and sold by Apple Inc., the latest of which is pre-loaded on all currently shipping under Macintosh series of personal computers. Mac OS X is the successor to the original Mac OS, which had been Apple's primary operating system since 1984. Unlike its predecessors, Mac OS X is a Unix-based operating system[18] built on technology developed atNeXT from the second half of the 1980s until early 1997, when Apple purchased the company.
The server edition, Mac OS X Server, is architecturally very similar to its desktop counterpart but usually runs on Apple's line of Macintosh server hardware. It includes workgroup management and administration software tools that provide simplified access to key network services, including a mail transfer agent, aSamba server, an LDAP server, a domain name server, and others.
[edit]Applications
This section does not cite any references or sources.
Please help improve this section by adding citations to reliable sources. Unverifiable material may be challenged and removed. (June 2008)
Main article: Application software
GIMP raster graphics editor
Application software employs the capabilities of a computer directly and thoroughly to a task that the user wishes to perform. This should be contrasted with system software which is involved in integrating a computer's various capabilities, but typically does not directly apply them in the performance of tasks that benefit the user. In this context the term application refers to both the application software and its implementation. A simple, if imperfect analogy in the world of hardware would be the relationship of an electric light bulb (an application) to an electric power generation plant (a system). The power plant merely generates electricity, not itself of any real use until harnessed to an application like the electric light that performs a service that benefits the user.
Typical examples of software applications are word processors, spreadsheets, and media players. Multiple applications bundled together as a package are sometimes referred to as an application suite. Microsoft Office and OpenOffice.org, which bundle together a word processor, a spreadsheet, and several other discrete applications, are typical examples. The separate applications in a suite usually have a user interface that has some commonality making it easier for the user to learn and use each application. And often they may have some capability to interact with each other in ways beneficial to the user. For example, a spreadsheet might be able to be embedded in a word processor document even though it had been created in the separate spreadsheet application.
End-user development tailors systems to meet the user's specific needs. User-written software include spreadsheet templates, word processor macros, scientific simulations, graphics and animation scripts. Even email filters are a kind of user software. Users create this software themselves and often overlook how important it is.
[edit]Lifetime
This section does not cite any references or sources.
Please help improve this section by adding citations to reliable sources. Unverifiable material may be challenged and removed. (April 2008)
Most personal computers are standardized to the point that purchased software is expected to run with little or no customization for the particular computer. Many PCs are also user-upgradeable, especially desktop and workstation class computers. Devices such as main memory, mass storage, even the motherboard and central processing unit may be easily replaced by an end user. This upgradeability is, however, not indefinite due to rapid changes in the personal computer industry. A PC that was considered top-of-the-line five or six years prior may be impractical to upgrade due to changes in industry standards. Such a computer usually must be totally replaced once it is no longer suitable for its purpose. This upgrade and replacement cycle is partially related to new releases of the primary mass-market operating system, which tends to drive the acquisition of new hardware and render obsolete previously serviceable hardware (planned obsolescence).
[edit]See also
Electronics portal
Look up Personal computer in
Wiktionary, the free dictionary.
Wikiquote has a collection of quotations related to:
Personal computer
Wikimedia Commons has media related to:
Personal computer
At Wikiversity, you can learn about: Introduction to Computers/Personal
Desktop computer
Desktop replacement computer
Gaming PC
List of computer system manufacturers
Personal Computer Museum
Public computer
Quiet PC
Supercomputer
An exploded view of a modern personal computer and peripherals:
Scanner
CPU (Microprocessor)
Primary storage (RAM)
Expansion cards (graphics cards, etc)
Power supply
Optical disc drive
Secondary storage (Hard disk)
Motherboard
Speakers
Monitor
System software
Application software
Keyboard
Mouse
External hard disk
Printer
Main article: Computer hardware
Posted by shehand at 2:39 AM 0 comments
Main article: Desktop computer
Dell OptiPlex desktop computer
Prior to the wide spread of PCs a computer that could fit on a desk was considered remarkably small. Today the phrase usually indicates a particular style of computer case. Desktop computers come in a variety of styles ranging from large vertical tower cases to small form factor models that can be tucked behind an LCD monitor. In this sense, the term 'desktop' refers specifically to a horizontally-oriented case, usually intended to have the display screen placed on top to save space on the desk top. Most modern desktop computers have separate screens and keyboards.
[edit]Nettop
Main article: Nettop (computer)
A subtype of desktops, called nettops, was introduced by Intel in February 2008 to describe low-cost, lean-function, desktop computers. A similar subtype of laptops (or notebooks) are the netbooks (see below).
[edit]Laptop
Main article: Laptop
A modern mid-range HP Laptop.
A laptop computer or simply laptop, also called a notebook computer or sometimes a notebook, is a small personal computer designed for mobility. Usually all of the interface hardware needed to operate the laptop, such as parallel and serial ports, graphics card, sound channel, etc., are built in to a single unit. Most laptops contain batteries to facilitate operation without a readily available electrical outlet. In the interest of saving power, weight and space, they usually share RAM with the video channel, slowing their performance compared to an equivalent desktop machine.
One main drawback of the laptop is that, due to the size and configuration of components, relatively little can be done to upgrade the overall computer from its original design. Some devices can be attached externally through ports (including via USB), however internal upgrades are not recommended or in some cases impossible, making the desktop PC more modular.
A subtype of notebooks, called subnotebooks, are computers with most of the features of a standard laptop computer but smaller. They are larger than hand-held computers, and usually run full versions of desktop/laptop operating systems. Ultra-Mobile PCs (UMPC) are usually considered subnotebooks, or more specifically, subnotebook Tablet PCs (see below). Netbooks are sometimes considered in this category, though they are sometimes separated in a category of their own (see below).
Desktop replacements, meanwhile, are large laptops meant to replace a desktop computer while keeping the mobility of a laptop.
[edit]Netbook
Main article: Netbook
Black ASUS Eee PC in proportions comparison with tissues
Netbook PCs are small portable computers in a "clamshell" design, that are designed specifically for wireless communication and access to the Internet. They are generally much lighter and cheaper thansubnotebooks, and have a smaller display, between 7" and 9", with a screen resolution between 800x600 and 1024x768. The operating systems and applications on them are usually specially modified so they can be comfortably used with a smaller sized screen, and the OS is often based on Linux, although some Netbooks also use Windows XP. Some Netbooks make use of their built in high speed Wireless connectivity to offload some of their applications software to Internet servers, through the principle of Cloud computing, as most Netbooks have small solid state storage systems instead of hard-disks. Storage capacities are usually in the 4 to 16 GB range. One of the first examples of such a system was the originalEEE PC.
[edit]Tablet PC
Main article: Tablet PC
HP Compaq tablet PC with rotating/removable keyboard.
A tablet PC is a notebook or slate-shaped mobile computer, first introduced by Pen computing in the early 90s with their PenGo Tablet Computer and popularized by Microsoft. Its touchscreen or graphics tablet/screen hybrid technology allows the user to operate the computer with a stylus or digital pen, or a fingertip, instead of a keyboard or mouse. The form factor offers a more mobile way to interact with a computer. Tablet PCs are often used where normal notebooks are impractical or unwieldy, or do not provide the needed functionality.
[edit]Ultra-Mobile PC
Main article: Ultra-Mobile PC
Samsung Q1 Ultra-Mobile PC.
The ultra-mobile PC (UMPC) is a specification for a small form factortablet PC. It was developed as a joint development exercise byMicrosoft, Intel, and Samsung, among others. Current UMPCs typically feature the Windows XP Tablet PC Edition 2005, Windows Vista Home Premium Edition, or Linux operating system and low-voltage Intel Pentium or VIA C7-M processors in the 1GHz range.
[edit]Home Theater PC
Main article: Home theater PC
Antec Fusion V2 home theater PC with keyboard on top.
A home theater PC (HTPC) is a convergence device that combines the functions of a personal computer and a digital video recorder. It is connected to a television or a television-sized computer display and is often used as a digital photo, music, video player, TV receiver and digital video recorder. Home theater PCs are also referred to as media center systems or media servers. The general goal in a HTPC is usually to combine many or all components of a home theater setup into one box. They can be purchased pre-configured with the required hardware and software needed to add television programming to the PC, or can be cobbled together out of discrete components as is commonly done with Windows Media Center, GB-PVR, SageTV, Famulent or LinuxMCE.
[edit]Pocket PC
Main article: Pocket PC
An O2 pocket PC
A pocket PC is a hardware specification for a handheld-sized computer (personal digital assistant) that runs theMicrosoft Windows Mobile operating system. It may have the capability to run an alternative operating system likeNetBSD or Linux. It has many of the capabilities of modern desktop PCs.
Currently there are tens of thousands of applications for handhelds adhering to the Microsoft Pocket PC specification, many of which are freeware. Some of these devices also include mobile phone features. Microsoft compliant Pocket PCs can also be used with many other add-ons like GPS receivers, barcode readers, RFID readers, and cameras. In 2007, with the release of Windows Mobile 6, Microsoft dropped the name Pocket PC in favor of a new naming scheme. Devices without an integrated phone are called Windows Mobile Classic instead of Pocket PC. Devices with an integrated phone and a touch screen are called Windows Mobile Professional.[9]
Posted by shehand at 2:38 AM 0 comments
Market
Market
In 2001 125 million personal computers were shipped in comparison to 48 thousand in 1977. More than 500 million PCs were in use in 2002 and one billion personal computers had been sold worldwide since mid-1970s till this time. Of the latter figure, 75 percent were professional or work related, while the rest sold for personal or home use. About 81.5 percent of PCs shipped had been desktop computers, 16.4 percentlaptops and 2.1 percent servers. United States had received 38.8 percent (394 million) of the computers shipped, Europe 25 percent and 11.7 percent had gone to Asia-Pacific region, the fastest-growing market as of 2002. The second billion was expected to be sold by 2008.[2] Almost half of all the households in Western Europe had a personal computer and a computer could be found in 40 percent of homes in United Kingdom, compared with only 13 percent in 1985.[3]
As of June 2008, the number of personal computers in use worldwide hit one billion, while another billion is expected to be reached by 2014. Mature markets like the United States, Western Europe and Japan accounted for 58 percent of the worldwide installed PCs. The emerging markets were expected to double their installed PCs by 2013 and to take 70 percent of the second billion PCs. About 180 million PCs (16 percent of the existing installed base) were expected to be replaced and 35 million to be dumped into landfill in 2008. The whole installed base grew 12 percent annually.[4][5]
[edit]Rugged computer industry
Besides the regular computer manufacturers, companies making especially rugged versions of computers have sprung up, offering alternatives for people operating their machines in extreme weather or environments. [6]
[edit]Netbooks and nettops
The emergence of new market segment of small, energy-efficient and low-cost devices (netbooks and nettops) could threaten established companies like Microsoft, Intel, HP or Dell, analysts said in July 2008. A market research firm International Data Corporation predicted that the category could grow from fewer than 500,000 in 2007 to 9 million in 2012 as the market for low cost and secondhand computers expands in developed economies. [7] Also, after Microsoft ceased selling of Windows XP for ordinary machines, it made an exception and continued to offer the operating system for netbook and nettop makers.[8]
Posted by shehand at 2:38 AM 0 comments
History of personal computers
ain article: History of personal computers
IBM 5150 as of 1981
The capabilities of the PC have changed greatly since the introduction of electronic computers. By the early 1970s, people in academic or research institutions had the opportunity for single-person use of a computer system in interactive mode for extended durations, although these systems would still have been too expensive to be owned by a single person. The introduction of the microprocessor, a single chip with all the circuitry that formerly occupied large cabinets, led to the proliferation of personal computers after about 1975. Early personal computers - generally called microcomputers - were sold often in Electronic kit form and in limited volumes, and were of interest mostly to hobbyists and technicians. Minimal programming was done by toggle switches, and output was provided by front panel indicators. Practical use required peripherals such as keyboards, computer terminals, disk drives, and printers. By 1977, mass-market pre-assembled computers allowed a wider range of people to use computers, focusing more on software applications and less on development of the processor hardware.
Throughout the late 1970s and into the 1980s, computers were developed for household use, offering personal productivity, programming and games. Somewhat larger and more expensive systems (although still low-cost compared with minicomputers and mainframes) were aimed for office and small business use. Workstations are characterized by high-performance processors and graphics displays, with large local disk storage, networking capability, and running under a multitasking operating system. Workstations are still used for tasks such as computer-aided design, drafting and modelling, computation-intensive scientific and engineering calculations, image processing, architectural modelling, and computer graphics for animation and motion picture visual effects.[1]
Eventually the market segments lost any technical distinction; business computers acquired color graphics capability and sound, and home computers and game systems users used the same processors and operating systems as office workers. Mass-market computers had graphics capabilities and memory comparable to dedicated workstations of a few years before. Even local area networking, originally a way to allow business computers to share expensive mass storage and peripherals, became a standard feature of the personal computers used at home.
Posted by shehand at 2:36 AM 0 comments
Tuesday, November 11, 2008
How Amazon Works
n 1995, Amazon.com sold its first book, which shipped from Jeff Bezos' garage in Seattle. In 2006, Amazon.com sells a lot more than books and has sites serving seven countries, with 21 fulfillment centers around the globe totaling more than 9 million square feet of warehouse space.
The story is an e-commerce dream, and Jeff Bezos was Time magazine's Person of the Year in 1999. The innovation and business savvy that sustains Amazon.com is legendary and, at times, controversial: The company owns dozens of patents on e-commerce processes that some argue should remain in the public domain. In this article, we'll find out what Amazon does, what makes it different from other e-commerce Web sites and how its technology infrastructure supports its multi-pronged approach to online sales.
Amazon.com Basics
Amazon.com sells lots and lots of stuff. The direct Amazon-to-buyer sales approach is really no different from what happens at most other large, online retailers except for its range of products. You can find beauty supplies, clothing, jewelry, gourmet food, sporting goods, pet supplies, books, CDs, DVDs,computers, furniture, toys, garden supplies, bedding and almost anything else you might want to buy. What makes Amazon a giant is in the details. Besides its tremendous product range, Amazon makes every possible attempt to customize the buyer experience.
When you arrive at the homepage, you'll find not only special offers and featured products, but if you've been to Amazon.com before, you'll also find some recommendations just for you. Amazon knows you by name and tries to be your personal shopper.
Courtesy Amazon.com
The embedded marketing techniques that Amazon employs to personalize your experience are probably the best example of the company's overall approach to sales: Know your customer very, very well.Customer tracking is an Amazon stronghold. If you let the Web site stick a cookie on your hard drive, you'll find yourself on the receiving end of all sorts of useful features that make your shopping experience pretty cool, like recommendations based on past purchases and lists of reviews and guides written by users who purchased the products you're looking at.
The other main feature that puts Amazon.com on another level is the multi-leveled e-commercestrategy it employs. Amazon.com lets almost anyone sell almost anything using its platform. You can find straight sales of merchandise sold directly by Amazon, like the books it sold back in the mid-'90s out of Jeff Bezos' garage -- only now they're shipped from a very big warehouse. Since 2000, you can also find goods listed by third-party sellers -- individuals, small companies and retailers like Target and Toys 'R Us. You can find used goods, refurbished goods and auctions. You could say that Amazon is simply the ultimate hub for selling merchandise on the Web, except that the company has recently added a more extroverted angle to its strategy.
Online Commerce
eBay
Electronic Payment
Can Facebook make you rich?
In addition to the affiliate program that lets anybody post Amazon links earn a commission on click-through sales, there's now a program that lets those affiliates (Amazon calls them "associates") build entire Web sites based on Amazon's platform. They can literally create mini Amazon Web sites if they want to, building on Amazon's huge database of products and applications for their own purposes. As long as any purchases go through Amazon, you can build a site called Amazonish.com, pull products directly from Amazon's servers, write your own guides and recommendations and earn a cut of any sales. Amazon has become a software developer's playground.
Before we dig deeper into Amazon's e-commerce methods, let's take a quick look at the technolo
Posted by shehand at 2:36 AM 0 comments
How does satellite Internet operate?
How do you access the Internet other than dial-up if you live too far from a phone company office for DSL and there is no cable TV on your street? Satellite Internet access may be worth considering. It's ideal for rural Internetusers who want broadband access. Satellite Internet does not use telephonelines or cable systems, but instead uses a satellite dish for two-way (upload and download) data communications. Upload speed is about one-tenth of the 500 kbps download speed. Cable and DSL have higher download speeds, but satellite systems are about 10 times faster than a normal modem.
Firms that offer or plan to offer two-way satellite Internet include StarBand, Pegasus Express, Teledesic and Tachyon. Tachyon service is available today in the United States, Western Europe and Mexico. Pegasus Express is the two-way version of DirecPC.
Two-way satellite Internet consists of:
Approximately a two-foot by three-foot dish
Two modems (uplink and downlink)
Coaxial cables between dish and modem
The key installation planning requirement is a clear view to the south, since the orbiting satellites are over the equator area. And, like satellite TV, trees and heavy rains can affect reception of the Internet signals.
Two-way satellite Internet uses Internet Protocol (IP) multicasting technology, which means up to 5,000 channels of communication can simultaneously be served by a single satellite. IP multicasting sends data from one point to many points (at the same time) by sending data in compressed format. Compression reduces the size of the data and the bandwidth. Usual dial-up land-based terrestrial systems have bandwidth limitations that prevent multicasting of this magnitude.
Graphic courtesy of StarBand
StarBand's System
Some satellite-Internet service still requires you to have a dial-up or cable modem connection for the data you send to the Internet. The satellite data downlink is just like the usual terrestrial link, except the satellite transmits the data to your computer via the same dish that would allow you to receive a Pay-Per-View television program.
So, if you are in a rural area and you want broadband access to the Internet, satellite Internet may be for you!
Posted by shehand at 2:30 AM 0 comments
How RAM Works
Memory Modules
The type of board and connector used for RAM in desktop computers has evolved over the past few years. The first types were proprietary, meaning that different computer manufacturers developed memory boards that would only work with their specific systems. Then came SIMM, which stands for single in-line memory module. This memory board used a 30-pin connector and was about 3.5 x .75 inches in size (about 9 x 2 cm). In most computers, you had to install SIMMs in pairs of equal capacity and speed. This is because the width of the bus is more than a single SIMM. For example, you would install two 8-megabyte (MB) SIMMs to get 16 megabytes total RAM. Each SIMM could send 8 bits of data at one time, while the system bus could handle 16 bits at a time. Later SIMM boards, slightly larger at 4.25 x 1 inch (about 11 x 2.5 cm), used a 72-pin connector for increased bandwidth and allowed for up to 256 MB of RAM.
From the top: SIMM, DIMM and SODIMM memory modules
As processors grew in speed and bandwidth capability, the industry adopted a new standard in dual in-line memory module (DIMM). With a whopping 168-pin or 184-pin connector and a size of 5.4 x 1 inch (about 14 x 2.5 cm), DIMMs range in capacity from 8 MB to 1 GB per module and can be installed singly instead of in pairs. Most PC memory modules and the modules for the Mac G5 systems operate at 2.5 volts, while older Mac G4 systems typically use 3.3 volts. Another standard, Rambus in-line memory module (RIMM), is comparable in size and pin configuration to DIMM but uses a special memory bus to greatly increase speed.
Many brands of notebook computers use proprietary memory modules, but several manufacturers use RAM based on the small outline dual in-line memory module (SODIMM) configuration. SODIMM cards are small, about 2 x 1 inch (5 x 2.5 cm), and have 144 or 200 pins. Capacity ranges from 16 MB to 1 GB per module. To conserve space, the Apple iMac desktop computer uses SODIMMs instead of the traditional DIMMs. Sub-notebook computers use even smaller DIMMs, known as MicroDIMMs, which have either 144 pins or 172 pins.
Most memory available today is highly reliable. Most systems simply have the memory controller check for errors at start-up and rely on that. Memory chips with built-in error-checking typically use a method known as parity to check for errors. Parity chips have an extra bit for every 8 bits of data. The way parity works is simple. Let's look at even parity first.
When the 8 bits in a byte receive data, the chip adds up the total number of 1s. If the total number of 1s is odd, the parity bit is set to 1. If the total is even, the parity bit is set to 0. When the data is read back out of the bits, the total is added up again and compared to the parity bit. If the total is odd and the parity bit is 1, then the data is assumed to be valid and is sent to the CPU. But if the total is odd and the parity bit is 0, the chip knows that there is an error somewhere in the 8 bits and dumps the data. Odd parity works the same way, but the parity bit is set to 1 when the total number of 1s in the byte are even.
The problem with parity is that it discovers errors but does nothing to correct them. If a byte of data does not match its parity bit, then the data are discarded and the system tries again. Computers in critical positions need a higher level of fault tolerance. High-end servers often have a form of error-checking known as error-correction code (ECC). Like parity, ECC uses additional bits to monitor the data in each byte. The difference is that ECC uses several bits for error checking -- how many depends on the width of the bus -- instead of one. ECC memory uses a special algorithm not only to detect single bit errors, but actually correct them as well. ECC memory will also detect instances when more than one bit of data in a byte fails. Such failures are very rare, and they are not correctable, even with ECC.
The majority of computers sold today use nonparity memory chips. These chips do not provide any type of built-in error checking, but instead rely on the memory controller for error detection.
Posted by shehand at 1:44 AM 0 comments
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Video card
Main article: Video card
ATI Radeon video card
The video card - otherwise called a graphics card, graphics adapter or video adapter - processes and renders the graphics output from the computer to the computer display, also called the visual display unit (VDU), and is an essential part of the modern computer. On older models, and today on budget models, graphics circuitry tended to be integrated with the motherboard but, for modern flexible machines, they are supplied in PCI, AGP, or PCI Express format.
When the IBM PC was introduced, most existing business-oriented personal computers used text-only display adapters and had no graphics capability. Home computers at that time had graphics compatible with television signals, but with low resolution by modern standards owing to the limited memory available to the eight-bit processors available at the time.
ATI Radeon video card
The video card - otherwise called a graphics card, graphics adapter or video adapter - processes and renders the graphics output from the computer to the computer display, also called the visual display unit (VDU), and is an essential part of the modern computer. On older models, and today on budget models, graphics circuitry tended to be integrated with the motherboard but, for modern flexible machines, they are supplied in PCI, AGP, or PCI Express format.
When the IBM PC was introduced, most existing business-oriented personal computers used text-only display adapters and had no graphics capability. Home computers at that time had graphics compatible with television signals, but with low resolution by modern standards owing to the limited memory available to the eight-bit processors available at the time.
Monday, November 24, 2008
Hard disk
Main article: Hard disk drive
A Western Digital 250 GB hard disk drive.
Mass storage devices store programs and data even when the power is off; they do require power to perform read and write functions during usage. Although semiconductor flash memory has dropped in cost, the prevailing form of mass storage in personal computers is still the electromechanical hard disk.
The disk drives use a sealed head/disk assembly (HDA) which was first introduced by IBM's "Winchester" disk system. The use of a sealed assembly allowed the use of positive air pressure to drive out particles from the surface of the disk, which improves reliability.
If the mass storage controller provides for expandability, a PC may also be upgraded by the addition of extra hard disk or optical disc drives. For example, DVD-ROMs, CD-ROMs, and various optical disc recorders may all be added by the user to certain PCs. Standard internal storage device interfaces are ATA,Serial ATA, SCSI, and CF+ type II in 2005.
A Western Digital 250 GB hard disk drive.
Mass storage devices store programs and data even when the power is off; they do require power to perform read and write functions during usage. Although semiconductor flash memory has dropped in cost, the prevailing form of mass storage in personal computers is still the electromechanical hard disk.
The disk drives use a sealed head/disk assembly (HDA) which was first introduced by IBM's "Winchester" disk system. The use of a sealed assembly allowed the use of positive air pressure to drive out particles from the surface of the disk, which improves reliability.
If the mass storage controller provides for expandability, a PC may also be upgraded by the addition of extra hard disk or optical disc drives. For example, DVD-ROMs, CD-ROMs, and various optical disc recorders may all be added by the user to certain PCs. Standard internal storage device interfaces are ATA,Serial ATA, SCSI, and CF+ type II in 2005.
Main memory
Main article: Primary storage
1GB DDR SDRAM 400 module
A PC's main memory is fast storage that is directly accessible by the CPU, and is used to store the currently executing program and immediately needed data. PCs use semiconductor random access memory (RAM) of various kinds such as DRAM or SRAM as their primary storage. Which exact kind depends on cost/performance issues at any particular time. Main memory is much faster than mass storage devices like hard disks or optical discs, but is usually volatile, meaning it does not retain its contents (instructions or data) in the absence of power, and is much more expensive for a given capacity than is most mass storage. Main memory is generally not suitable for long-term or archival data storage.
1GB DDR SDRAM 400 module
A PC's main memory is fast storage that is directly accessible by the CPU, and is used to store the currently executing program and immediately needed data. PCs use semiconductor random access memory (RAM) of various kinds such as DRAM or SRAM as their primary storage. Which exact kind depends on cost/performance issues at any particular time. Main memory is much faster than mass storage devices like hard disks or optical discs, but is usually volatile, meaning it does not retain its contents (instructions or data) in the absence of power, and is much more expensive for a given capacity than is most mass storage. Main memory is generally not suitable for long-term or archival data storage.
Central processing unit
Main article: Central processing unit
AMD Athlon 64 CPU.
The central processing unit, or CPU, is that part of a computer which executes software programinstructions. In older computers this circuitry was formerly on several printed circuit boards, but in PCs is a single integrated circuit. Nearly all PCs contain a type of CPU known as a microprocessor. The microprocessor often plugs into the motherboard using one of many different types of sockets. IBM PC compatible computers use an x86-compatible processor, usually made by Intel, AMD, VIA Technologies orTransmeta. Apple Macintosh computers were initially built with the Motorola 680x0 family of processors, then switched to the PowerPC series (a RISC architecture jointly developed by Apple Computer, IBM andMotorola), but as of 2006, Apple switched again, this time to x86-compatible processors by Intel. Modern CPUs are equipped with a fan attached via heat sink.
[edit]Motherboard
Main article: Motherboard
Asus motherboard
The motherboard, also referred to as systemboard or mainboard, is the primary circuit board within a personal computer. Many other components connect directly or indirectly to the motherboard. Motherboards usually contain one or more CPUs, supporting circuitry - usually integrated circuits (ICs) - providing the interface between the CPU memory and input/output peripheral circuits, main memory, and facilities for initial setup of the computer immediately after power-on (often called boot firmware or, in IBM PC compatible computers, a BIOS). In many portable and embedded personal computers, the motherboard houses nearly all of the PC's core components. Often a motherboard will also contain one or more peripheral buses and physical connectors for expansion purposes. Sometimes a secondary daughter boardis connected to the motherboard to provide further expandability or to satisfy space constraints.
AMD Athlon 64 CPU.
The central processing unit, or CPU, is that part of a computer which executes software programinstructions. In older computers this circuitry was formerly on several printed circuit boards, but in PCs is a single integrated circuit. Nearly all PCs contain a type of CPU known as a microprocessor. The microprocessor often plugs into the motherboard using one of many different types of sockets. IBM PC compatible computers use an x86-compatible processor, usually made by Intel, AMD, VIA Technologies orTransmeta. Apple Macintosh computers were initially built with the Motorola 680x0 family of processors, then switched to the PowerPC series (a RISC architecture jointly developed by Apple Computer, IBM andMotorola), but as of 2006, Apple switched again, this time to x86-compatible processors by Intel. Modern CPUs are equipped with a fan attached via heat sink.
[edit]Motherboard
Main article: Motherboard
Asus motherboard
The motherboard, also referred to as systemboard or mainboard, is the primary circuit board within a personal computer. Many other components connect directly or indirectly to the motherboard. Motherboards usually contain one or more CPUs, supporting circuitry - usually integrated circuits (ICs) - providing the interface between the CPU memory and input/output peripheral circuits, main memory, and facilities for initial setup of the computer immediately after power-on (often called boot firmware or, in IBM PC compatible computers, a BIOS). In many portable and embedded personal computers, the motherboard houses nearly all of the PC's core components. Often a motherboard will also contain one or more peripheral buses and physical connectors for expansion purposes. Sometimes a secondary daughter boardis connected to the motherboard to provide further expandability or to satisfy space constraints.
Computer case
Main article: Computer case
A stripped ATX case lying on its side.
A computer case is the enclosure that contains the main components of a computer. Cases are usually constructed from steel, aluminium, or plastic, although other materials such as wood, plexiglas or fans[10]have also been used in case designs. Cases can come in many different sizes, or form factors. The size and shape of a computer case is usually determined by the form factor of the motherboard that it is designed to accommodate, since this is the largest and most central component of most computers. Consequently, personal computer form factors typically specify only the internal dimensions and layout of the case. Form factors for rack-mounted and blade servers may include precise external dimensions as well, since these cases must themselves fit in specific enclosures.
Currently, the most popular form factor for desktop computers is ATX, although microATX and small form factors have become very popular for a variety of uses. Companies like Shuttle Inc. and AOpen have popularized small cases, for which FlexATX is the most common motherboard size.
A stripped ATX case lying on its side.
A computer case is the enclosure that contains the main components of a computer. Cases are usually constructed from steel, aluminium, or plastic, although other materials such as wood, plexiglas or fans[10]have also been used in case designs. Cases can come in many different sizes, or form factors. The size and shape of a computer case is usually determined by the form factor of the motherboard that it is designed to accommodate, since this is the largest and most central component of most computers. Consequently, personal computer form factors typically specify only the internal dimensions and layout of the case. Form factors for rack-mounted and blade servers may include precise external dimensions as well, since these cases must themselves fit in specific enclosures.
Currently, the most popular form factor for desktop computers is ATX, although microATX and small form factors have become very popular for a variety of uses. Companies like Shuttle Inc. and AOpen have popularized small cases, for which FlexATX is the most common motherboard size.
Hardware
Main article: Computer hardware
A typical hardware setup of a desktop computer consists of:
computer case with power supply
central processing unit (processor)
motherboard
memory card
hard disk
video card
visual display unit (monitor)
optical disc (usually DVD-ROM or DVD Writer)
keyboard and pointing device
These components can usually be put together with little knowledge to build a computer. The motherboard is a main part of a computer that connects all devices together. The memory card(s), graphics card and processor are mounted directly onto the motherboard (the processor in a socket and the memory and graphics cards inexpansion slots). The mass storage is connected to it with cables and can be installed in the computer case or in a separate case. This is the same for the keyboard and mouse, except that they are external and connect to the I/O panel on the back of the computer. The monitor is also connected to the I/O panel, either through an onboard port on the motherboard, or a port on the graphics card.
Several functions (implemented by chipsets) can be integrated into the motherboard, typically USB and network, but also graphics and sound. Even if these are present, a separate card can be added if what is available isn't sufficient. The graphics and sound card can have a break out box to keep the analog parts away from the electromagnetic radiation inside the computer case. For really large amounts of data, a tape drive can be used or (extra) hard disks can be put together in an external case.
The hardware capabilities of personal computers can sometimes be extended by the addition of expansion cards connected via an expansionbus. Some standard peripheral buses often used for adding expansion cards in personal computers as of 2005 are PCI, AGP (a high-speed PCI bus dedicated to graphics adapters), and PCI Express. Most personal computers as of 2005 have multiple physical PCI expansion slots. Many also include an AGP bus and expansion slot or a PCI Express bus and one or more expansion slots, but few PCs contain both buses.
A typical hardware setup of a desktop computer consists of:
computer case with power supply
central processing unit (processor)
motherboard
memory card
hard disk
video card
visual display unit (monitor)
optical disc (usually DVD-ROM or DVD Writer)
keyboard and pointing device
These components can usually be put together with little knowledge to build a computer. The motherboard is a main part of a computer that connects all devices together. The memory card(s), graphics card and processor are mounted directly onto the motherboard (the processor in a socket and the memory and graphics cards inexpansion slots). The mass storage is connected to it with cables and can be installed in the computer case or in a separate case. This is the same for the keyboard and mouse, except that they are external and connect to the I/O panel on the back of the computer. The monitor is also connected to the I/O panel, either through an onboard port on the motherboard, or a port on the graphics card.
Several functions (implemented by chipsets) can be integrated into the motherboard, typically USB and network, but also graphics and sound. Even if these are present, a separate card can be added if what is available isn't sufficient. The graphics and sound card can have a break out box to keep the analog parts away from the electromagnetic radiation inside the computer case. For really large amounts of data, a tape drive can be used or (extra) hard disks can be put together in an external case.
The hardware capabilities of personal computers can sometimes be extended by the addition of expansion cards connected via an expansionbus. Some standard peripheral buses often used for adding expansion cards in personal computers as of 2005 are PCI, AGP (a high-speed PCI bus dedicated to graphics adapters), and PCI Express. Most personal computers as of 2005 have multiple physical PCI expansion slots. Many also include an AGP bus and expansion slot or a PCI Express bus and one or more expansion slots, but few PCs contain both buses.
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