[By Zahdiullah]
computer http://en.wikipedia.org/wiki/Computer
Computer programming http://en.wikipedia.org/wiki/Computer_programming
[GOOGLE] http://www.google.com
Tuesday, 29 November 2011
Tuesday, 22 November 2011
PARTS OF A CPU
CD-ROM:-
Stands for "Compact Disc Read-Only Memory." A CD-ROM is a CD that can be read by a computer with an optical drive. The "ROM" part of the term means the data on the disc is "read-only," or cannot altered or erased. Because of this feature and their large capacity, CD-ROMs are a great media format for retail software. The first CD-ROMs could hold about 600 MB of data, but now they can hold up to 700 MB. CD-ROMs share the same technology as audio CDs, but they are formatted differently, allowing them to store many types of data.
Processor:-
This little chip is the heart of a computer. Also referred to as the "microprocessor," the processor does all the computations such as adding, subtracting, multiplying, and dividing. In PCs, the most popular microprocessor used is the Intel Pentium chip, whereas Macintosh computers use the PowerPC chip (developed by Motorola, IBM, and Apple).
The speed of a computer's processor is measured in megahertz, or cycles per second. But higher megahertz doesn't always mean better performance. Though a 600-MHz chip has a clock speed that is twice as fast as a 300-Mhz chip, it doesn't mean that the computer with the 600-Mhz chip will run twice as fast. This is because the speed of a computer is also influenced by other factors, such as the efficiency of the processor, the bus architecture, the amount of memory available, and the software that is running on the computer. Some processors can complete more operations per clock cycle than other processors, making them more efficient than other processors with higher clock speeds. This is why the PowerPC chip is typically faster than Pentium chips at that are clocked at higher megahertz.
Hard Drive:-
The hard drive is what stores all your data. It houses the hard disk, where all your files and folders are physically located. A typical hard drive is only slightly larger than your hand, yet can hold over 100 GB of data. The data is stored on a stack of disks that are mounted inside a solid encasement. These disks spin extremely fast (typically at either 5400 or 7200 RPM) so that data can be accessed immediately from anywhere on the drive. The data is stored on the hard drive magnetically, so it stays on the drive even after the power supply is turned off.
The term "hard drive" is actually short for "hard disk drive." The term "hard disk" refers to the actual disks inside the drive. However, all three of these terms are usually seen as referring to the same thing -- the place where your data is stored. Since I use the term "hard drive" most often, that is the correct one to use.
Modem:-
The word modem is actually short for Modulator/Demodulator. (There's something you can really impress your friends with). A modem is a communications device that can be either internal or external to your computer. It allows one computer to connect another computer and transfer data over telephone lines. The original dial-up modems are becoming obsolete because of their slow speeds and are being replaced by the much faster cable and DSL modems.
Motherboard:-
Each motherboard has a collection of chips and controllers known as the chipset. When new motherboards are developed, they often use new chipsets. The good news is that these boards are typically more efficient and faster than their predecessors. The bad news is that older components often do not work with new chipsets. Of course, if you are planning on upgrading multiple components, it may be more cost-effective to just buy a new computer.
NIC:-
Stands for "Network Interface Card." Pronounced "nick," this is the card that physically makes the connection between the computer and the network cable. These cards typically use an Ethernet connection and are available in 10, 100, and 1000 Base-T configurations. A 100 Base-T card can transfer data at 100 Mbps. The cards come in ISA and PCI versions and are made by companies like 3Com and LinkSys. So if you want to connect your computer to a network, you better get yourself a NIC.
Sound Card:-
The sound card is a component inside the computer that provides audio input and output capabilities. Most sound cards have at least one analog line input and one stereo line output connection. The connectors are typically 3.5 mm minijacks, which are the size most headphones use. Some sound cards also support digital audio input and output, either through a standard TRS (tip-ring-sleeve) connection or via an optical audio port, such as Toslink connector.
While there are many types of sound cards, any type that produces an analog output must include a digital-to-analog converter (DAC). This converts the outgoing signal from digital to analog, which can be played through most speaker systems. Sounds cards that support analog input also require an analog-to-digital converter (ADC). This digitizes the incoming analog signal, so the computer can process it.
In some computers, the sound card is part of the motherboard, while other machines may have an actual card that reside in a PCI slot. If you want to more audio capabilities to your computer, such as additional input or output channels, you can install a new sound card. Professional sound cards often support higher sampling rates (such as 192 kHz instead of 44.1 kHz) and may have more inputs and outputs. Some cards may also have 1/4 in. connectors instead of 3.5 mm, which accommodates most instrument outputs.
While professional sound cards can add more audio capabilities to your computer, another popular option for multi-channel recording is a breakout box. This is an external box that typically includes a built-in sound card and multiple audio connections. For example, a breakout box may support 16 channels of audio, which would be impossible to fit on a single card. Most breakout boxes connect to a Firewire or USB port, though some connect to a sound card specifically designed to communicate with the box.
Video Card:-
Most of the processing done on a computer is done via the computer's central processing unit, or CPU. So in order to give the CPU a break and help it run more efficiently, a video card can be used to process the graphics portion of the processing load. Because most of today's programs are graphically oriented, the video card can help almost any program run more efficiently. However, the difference in performance is especially noticeable in image editing applications and 3D games.
Video cards, also called graphics accelerators, can speed up both 2D and 3D graphics rendering. Programs such as photo editors and Web browsers may benefit from 2D acceleration, while CAD design programs and video games will most likely benefit from the card's 3D acceleration. Some programs rely so heavily on the video card, that they will not run if a supported video card is not installed.
Most video cards support the OpenGL and DirectX libraries. These libraries include commands for manipulating graphics that programmers can include in their code. Some of these commands may include moving or rotating an object, morphing polygons, or casting light and creating shadows. By using standard OpenGL or DirectX functions, it makes it easier for developers to create graphically-oriented programs. Of course, it also makes it necessary for the computer to include a supported video card in order for the program to run.
Video cards are typically installed in either the PCI or AGP slots in the back of a computer. Most computers come with a video card installed in one of these slots, which means it can be upgraded at a later time.
Floppy Disk:-
Floppy disks have an interesting name, considering they do not appear to be "floppy." However, if you take the actual disk out of the protective casing, you will discover that the disk is, in fact, rather flexible. It is coated with iron oxide and stores data magnetically, just like a hard disk.
The first floppy disks were created in 1969, the same year the Internet had its origin. These disks were 8 inches in diameter and were read-only, like a CD-ROM, meaning no data could be written to them by the user. The first 8 inch disks only held 80KB of data, but later versions could hold as much as 800KB.
In 1978, a 5.25 inch disk was introduced, which could hold a whopping 360KB of data. Later revisions of the 5.25 inch floppy disk could store 1.2MB. These disks were used in early desktop PCs, such as the Apple IIe. In 1987, the 3.5 inch HD (high density) floppy disk was released, which could hold 1.44MB after being formatted. These disks were a little more durable than the 5.25 inch disks and were also more portable. For the next decade, the 3.5 inch floppy disk became the standard means of distributing commercial software titles and backing up personal data.
In the late 1990s, CD-ROMs began to replace floppy disks as the standard means of distributing software. A few years later, consumers began migrating to recordable CDs for backing up their data. Apple's original iMac, released in 1998, was the first mainstream computer to not even include a floppy disk drive. While it took several years, many PC manufacturers eventually followed suit.
Now most software is distributed on CDs and DVDs and most people back up their data either on recordable CDs or USB flash drives. Floppy disks are finally becoming a thing of the past, which is good, considering they are notorious for losing data. Still, the floppy disk will always have a special place in the hearts and minds of veteran computer users as it was the data storage medium many people grew up with.
Stands for "Compact Disc Read-Only Memory." A CD-ROM is a CD that can be read by a computer with an optical drive. The "ROM" part of the term means the data on the disc is "read-only," or cannot altered or erased. Because of this feature and their large capacity, CD-ROMs are a great media format for retail software. The first CD-ROMs could hold about 600 MB of data, but now they can hold up to 700 MB. CD-ROMs share the same technology as audio CDs, but they are formatted differently, allowing them to store many types of data.
Processor:-
This little chip is the heart of a computer. Also referred to as the "microprocessor," the processor does all the computations such as adding, subtracting, multiplying, and dividing. In PCs, the most popular microprocessor used is the Intel Pentium chip, whereas Macintosh computers use the PowerPC chip (developed by Motorola, IBM, and Apple).
The speed of a computer's processor is measured in megahertz, or cycles per second. But higher megahertz doesn't always mean better performance. Though a 600-MHz chip has a clock speed that is twice as fast as a 300-Mhz chip, it doesn't mean that the computer with the 600-Mhz chip will run twice as fast. This is because the speed of a computer is also influenced by other factors, such as the efficiency of the processor, the bus architecture, the amount of memory available, and the software that is running on the computer. Some processors can complete more operations per clock cycle than other processors, making them more efficient than other processors with higher clock speeds. This is why the PowerPC chip is typically faster than Pentium chips at that are clocked at higher megahertz.
Hard Drive:-
The hard drive is what stores all your data. It houses the hard disk, where all your files and folders are physically located. A typical hard drive is only slightly larger than your hand, yet can hold over 100 GB of data. The data is stored on a stack of disks that are mounted inside a solid encasement. These disks spin extremely fast (typically at either 5400 or 7200 RPM) so that data can be accessed immediately from anywhere on the drive. The data is stored on the hard drive magnetically, so it stays on the drive even after the power supply is turned off.
The term "hard drive" is actually short for "hard disk drive." The term "hard disk" refers to the actual disks inside the drive. However, all three of these terms are usually seen as referring to the same thing -- the place where your data is stored. Since I use the term "hard drive" most often, that is the correct one to use.
Modem:-
The word modem is actually short for Modulator/Demodulator. (There's something you can really impress your friends with). A modem is a communications device that can be either internal or external to your computer. It allows one computer to connect another computer and transfer data over telephone lines. The original dial-up modems are becoming obsolete because of their slow speeds and are being replaced by the much faster cable and DSL modems.
The motherboard is the main circuit board of your computer and is also known as the mainboard or logic board. If you ever open your computer, the biggest piece of silicon you see is the motherboard. Attached to the motherboard, you'll find the CPU, ROM, memory RAM expansion slots, PCI slots, and USB ports. It also includes controllers for devices like the hard drive, DVD drive, keyboard, and mouse. Basically, the motherboard is what makes everything in your computer work together.
Each motherboard has a collection of chips and controllers known as the chipset. When new motherboards are developed, they often use new chipsets. The good news is that these boards are typically more efficient and faster than their predecessors. The bad news is that older components often do not work with new chipsets. Of course, if you are planning on upgrading multiple components, it may be more cost-effective to just buy a new computer.
NIC:-
Stands for "Network Interface Card." Pronounced "nick," this is the card that physically makes the connection between the computer and the network cable. These cards typically use an Ethernet connection and are available in 10, 100, and 1000 Base-T configurations. A 100 Base-T card can transfer data at 100 Mbps. The cards come in ISA and PCI versions and are made by companies like 3Com and LinkSys. So if you want to connect your computer to a network, you better get yourself a NIC.
Sound Card:-
The sound card is a component inside the computer that provides audio input and output capabilities. Most sound cards have at least one analog line input and one stereo line output connection. The connectors are typically 3.5 mm minijacks, which are the size most headphones use. Some sound cards also support digital audio input and output, either through a standard TRS (tip-ring-sleeve) connection or via an optical audio port, such as Toslink connector.
While there are many types of sound cards, any type that produces an analog output must include a digital-to-analog converter (DAC). This converts the outgoing signal from digital to analog, which can be played through most speaker systems. Sounds cards that support analog input also require an analog-to-digital converter (ADC). This digitizes the incoming analog signal, so the computer can process it.
In some computers, the sound card is part of the motherboard, while other machines may have an actual card that reside in a PCI slot. If you want to more audio capabilities to your computer, such as additional input or output channels, you can install a new sound card. Professional sound cards often support higher sampling rates (such as 192 kHz instead of 44.1 kHz) and may have more inputs and outputs. Some cards may also have 1/4 in. connectors instead of 3.5 mm, which accommodates most instrument outputs.
While professional sound cards can add more audio capabilities to your computer, another popular option for multi-channel recording is a breakout box. This is an external box that typically includes a built-in sound card and multiple audio connections. For example, a breakout box may support 16 channels of audio, which would be impossible to fit on a single card. Most breakout boxes connect to a Firewire or USB port, though some connect to a sound card specifically designed to communicate with the box.
Video Card:-
Most of the processing done on a computer is done via the computer's central processing unit, or CPU. So in order to give the CPU a break and help it run more efficiently, a video card can be used to process the graphics portion of the processing load. Because most of today's programs are graphically oriented, the video card can help almost any program run more efficiently. However, the difference in performance is especially noticeable in image editing applications and 3D games.
Video cards, also called graphics accelerators, can speed up both 2D and 3D graphics rendering. Programs such as photo editors and Web browsers may benefit from 2D acceleration, while CAD design programs and video games will most likely benefit from the card's 3D acceleration. Some programs rely so heavily on the video card, that they will not run if a supported video card is not installed.
Most video cards support the OpenGL and DirectX libraries. These libraries include commands for manipulating graphics that programmers can include in their code. Some of these commands may include moving or rotating an object, morphing polygons, or casting light and creating shadows. By using standard OpenGL or DirectX functions, it makes it easier for developers to create graphically-oriented programs. Of course, it also makes it necessary for the computer to include a supported video card in order for the program to run.
Video cards are typically installed in either the PCI or AGP slots in the back of a computer. Most computers come with a video card installed in one of these slots, which means it can be upgraded at a later time.
Floppy Disk:-
Floppy disks have an interesting name, considering they do not appear to be "floppy." However, if you take the actual disk out of the protective casing, you will discover that the disk is, in fact, rather flexible. It is coated with iron oxide and stores data magnetically, just like a hard disk.
The first floppy disks were created in 1969, the same year the Internet had its origin. These disks were 8 inches in diameter and were read-only, like a CD-ROM, meaning no data could be written to them by the user. The first 8 inch disks only held 80KB of data, but later versions could hold as much as 800KB.
In 1978, a 5.25 inch disk was introduced, which could hold a whopping 360KB of data. Later revisions of the 5.25 inch floppy disk could store 1.2MB. These disks were used in early desktop PCs, such as the Apple IIe. In 1987, the 3.5 inch HD (high density) floppy disk was released, which could hold 1.44MB after being formatted. These disks were a little more durable than the 5.25 inch disks and were also more portable. For the next decade, the 3.5 inch floppy disk became the standard means of distributing commercial software titles and backing up personal data.
In the late 1990s, CD-ROMs began to replace floppy disks as the standard means of distributing software. A few years later, consumers began migrating to recordable CDs for backing up their data. Apple's original iMac, released in 1998, was the first mainstream computer to not even include a floppy disk drive. While it took several years, many PC manufacturers eventually followed suit.
Now most software is distributed on CDs and DVDs and most people back up their data either on recordable CDs or USB flash drives. Floppy disks are finally becoming a thing of the past, which is good, considering they are notorious for losing data. Still, the floppy disk will always have a special place in the hearts and minds of veteran computer users as it was the data storage medium many people grew up with.
Wednesday, 16 November 2011
Input and Output devices of computer system
INPUT AND OUTPUT DEVICES
INPUT DEVICES:-Mouse:-
While most people don't want to see a mouse running around in their home, they typically don't have a problem seeing one sitting by their computer. This is because, along with the keyboard, the mouse is one of the primary input devices used with today's computers. The name comes from the small shape of the mouse, which you can move quickly back and forth on the mouse pad, and the cord, which represents the mouse's tail. Of course, if you are using a wireless mouse, the analogy does not work so well.
All mice have at least one button, though most mice have two or three. Some also have additional buttons on the sides, which can be assigned to different commands. Most mice also have a scroll-wheel, which lets you scroll up and down documents and Web pages by just rolling the wheel with your index finger.
Early mice tracked movement using a ball in the bottom of the mouse. This "mouse ball" pushed against different rollers as it moved, measuring the mouse's speed and direction. However, now most mice use optical technology, which uses a beam of light to track the mouse's motion. Optical mice are more accurate than roller-based mice and they have the added bonus of not getting dirty inside.
Keyboard:-
As the name implies, a keyboard is basically a board of keys. Along with the mouse, the keyboard is one of the primary input devices used with a computer. The keyboard's design comes from the original typewriter keyboards, which arranged letters and numbers in a way that prevented the type-bars from getting jammed when typing quickly. This keyboard layout is known as the QWERTY design, which gets its name from the first six letters across in the upper-left-hand corner of the keyboard.
While the design of computer keyboards may have come from typewriters, today's keyboards have many other keys as well. Modifier keys, such as Control, Alt/Option, and Command (Mac) or the Windows key (Windows) can be used in conjunction with other keys as "shortcuts" to perform certain operations. For example, pressing Command-S (Mac), or Control-S (Windows) typically saves a document or project you are working on. Most of today's computer keyboards also have a row of function keys (F1 through F16) along the top of the keyboard, arrow keys arranged in an upside-down T, and a numeric keypad on the right-hand side. Some keyboards have even more buttons, allowing you to change the system volume, eject a CD, or open programs such as your e-mail or Web browser.
CD-ROM:-
It Stands for "Compact Disc Read-Only Memory." A CD-ROM is a CD that can be read by a computer with an optical drive. The "ROM" part of the term means the data on the disc is "read-only," or cannot altered or erased. Because of this feature and their large capacity, CD-ROMs are a great media format for retail software. The first CD-ROMs could hold about 600 MB of data, but now they can hold up to 700 MB. CD-ROMs share the same technology as audio CDs, but they are formatted differently, allowing them to store many types of data.
OUTPUT DEVICES
Monitor:-
The term "monitor" is often used synonymously with "computer screen" or "display." The monitor displays the computer's user interface and open programs, allowing the user to interact with the computer, typically using the keyboard and mouse.
Older computer monitors were built using cathode ray tubes (CRTs), which made them rather heavy and caused them to take up a lot of desk space. Most modern monitors are built using LCD technology and are commonly referred to as flat screen displays. These thin monitors take up much less space than the older CRT displays. This means people with LCD monitors have more desk space to clutter up with stacks of papers, pens, and other objects.
Finally, monitors also refer to speakers used for monitoring sound. Audio engineers typically use "studio monitors" to listen to recordings. These high-end speakers allow the engineers to accurately mix and master audio tracks. So a sound mixer could be monitoring a recording visually using a computer monitor, while monitoring the sound using audio monitors at the same. As you can tell, "monitor" serves as a rather multipurpose word.
Printer
A printer is an output device that prints paper documents. This includes text documents, images, or a combination of both. The two most common types of printers are inkjet and laser printers. Inkjet printers are commonly used by consumers, while laser printers are a typical choice for businesses. Dot matrix printers, which have become increasingly rare, are still used for basic text printing.
The printed output produced by a printer is often called a hard copy, which is the physical version of an electronic document. While some printers can only print black and white hard copies, most printers today can produce color prints. In fact, many home printers can now produce high-quality photo prints that rival professionally developed photos. This is because modern printers have a high DPI (dots per inch) setting, which allows documents to printed with a very fine resolution.
In order to print a document, the electronic data must be sent from the computer to the printer. Many software programs, such as word processors and image editing programs, include a "Print..." option in the File menu. When you select "Print," you will typically presented with a Print dialog box. This box allows you to select the print output settings before sending the document to the printer. After choosing the appropriate settings, you can hit the Print button, which will send the document to the printer.
Of course for the document to print, the printer must be turned on and connected to the computer. Most modern printers are connected using a standard USB cable. However, some printers can be wirelessly connected to one or more computers over a Wi-Fi network. You can also use more than one printer on a single computer, as long as the correct drivers are installed.
While printers are notorious for breaking down at inopportune times, modern printers are fortunately more reliable than the printers of the past. Of course, keeping extra ink or toner cartridges on hand is still your responsibility.
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