overview of personal computer (pc) (by: shujaat abbas)
TRANSCRIPT
Overview of PC• In this Lecture you learn about the all major component/
Hardware of the PC.
• Object:
• To See and understanding all the major parts of PC.
• You can Understanding all the names of those parts /
Components which is inside or out side of the PC.
• You can easily recognize every component of the PC.
• You can write the list of parts/ Components of the PC.
• The Case• The case is the box that houses the PC. All of the hardware,
except for the peripherals, is housed inside the case. There are two common styles of cases: "desktop" and "tower." The desktop case usually sits under the monitor and is roughly the size of two or three shoe boxes side by side. The tower case stands upright on one end and is usually placed on the floor. Tower cases can be the same size as a desktop case but often range up much larger. Another, less common, case style is the "rack mount" case which slides in and out of an equipment rack.
• The Motherboard• The motherboard is the largest and most fundamental
component of a PC. Every other hardware component is somehow attached to the motherboard. The motherboard is the common link for every component to communicate and work together.
• The motherboard has a series of slots, sockets and connectors for connecting the various components of a PC. The memory, accessory cards, and CPU are installed directly onto the motherboard in most cases. The drives and peripherals communicate with the motherboard through wired connections.
• The CPU• The CPU, which stands for Central Processing Unit, is the brain of the PC. It is
often referred to as the "processor" or "chip". The CPU directs, coordinates and communicates with the hardware components and performs all of the "thinking". What a CPU actually does is perform mathematical calculations. It is the software that people write that translates those calculations into useful functions for us.
• The speed of the CPU, now measured in gigahertz (GHz), generally speaking relates to the number of calculations it can perform in one second. Higher gigahertz ratings translate to a greater number of calculations or instructions per second. It is more complicated than that, but it is a reasonable way to think of the speed.
• As the speed of new CPUs increase, the difference is becoming less obvious to computer users. A CPU that is twice as fast as another one will not result in a PC running twice as fast. The CPU has to wait for other, slower components and for the user too. The CPU spends a lot of time sitting idle, waiting for something to do.
• CPUs have something called a "cache" or memory cache. The memory cache is where information is stored that the CPU is likely to need soon. This memory is in addition to the normal memory installed in a PC. The difference is that the cache is built right onto the CPU (and/or very near the CPU), and it is much faster than conventional memory. Cache memory was developed to reduce the time the CPU had to wait while information was retrieved from the standard memory.
• The RAM Memory Module• The memory chips store information, temporarily, for short term
use. A PC's memory is an entirely different thing from the hard disk "memory". The hard disk stores information "permanently" for long term use.
• A PC's memory only contains information when the PC is on. When the PC is turned off, the information in the memory chips disappears. The information in memory is similar to a thought, it gets replaced when you start thinking about something else. Hard disk memory is like writing down the information and storing it in a filing cabinet.
• The Hard Disk Drive• A hard disk (also called a "hard drive") is much like a
filing cabinet. The programs and data are stored on the hard disk and the computer accesses them as needed. When the computer accesses the hard drive, it is reading the stored information into memory. That memory is the temporary workspace. The original file on the hard disk is left undisturbed. When the computer stores information, it writes the data to the hard disk. That process results in the old file being replaced or modified with the new information. If you save data to a new file, or install new software, the information is written to the disk in an available, unused portion of the disk.
• The Power Supply• Where the power cord connects to the back of the PC
is the power supply. The power supply converts AC current from the wall outlet to the appropriate DC voltages for the various components of the computer.
• The power supply has a fan built into it to keep itself and the PC cool. Most PC's have at least one additional cooling fan, often mounted directly on the CPU. The power supply or its internal fan can wear out. Fortunately, when this happens in most cases, the entire unit is easily replaced.
• The Floppy Disk Drive• The floppy disk drive is a device that records data
onto a removable storage disk called a floppy disk. Floppy disks, also called "floppies", were the most basic storage medium for data. However their limited capacity, typically 1.44 megabytes, rendered them obsolete with the development of writeable CDs and DVDs and USB flash drives. Once found on all PCs, manufacturers no longer include them in new PCs.
• A floppy disk was used to copy files from one PC to another PC or for making backup copies of files.
• The CD and DVD Drive• The CD-ROM and DVD-ROM drive are devices that read data, music and video
off of a CD (compact disc) or DVD (Digital Versatile or Video Disc). The ROM part stands for "Read Only Memory", which means the disc can only be read from, but not written to. More commonly today, CDs and DVDs can be both read and written to. Drives are typically labeled DVD-RW, indicating the drive is capable of reading (R) and writing (W).
• The CD replaced the floppy disk as the medium of choice for storage of transportable data. When you purchase software today, it is stored on CDs. The DVD has even greater capacity and is supplanting the CD. Breakthroughs with high definition technology is increasing the capacity of DVDs even further.
• A CD or DVD is spun at high speed inside the drive while a laser is directed at the surface to read or write data. The drive speed is referenced as 12X or 12 speed (or any other number). This simply means that it spins the CD that many times faster than the original industry specification. So, a 48X CD-ROM spins the CD up to 48 times faster than the original specification. Faster is better. The speeds of a read-write drive are expressed like this, 4X 4X 32X. This means it can write to the disc up to 4 times the spec speed, rewrite the disc up to 4 times spec speed and read the disc up to 32 times the spec speed.
• The Graphics Card or Video Card• The video adapter card or graphics adapter translates
information into graphics and text that appear on the monitor screen.
• The graphics adapter plugs into a slot on the motherboard or is incorporated directly into the electronics of the motherboard. A special slot designated specifically for the graphics card called the AGP slot (Advanced Graphics Port) has been superseded by the PCI-e or PCI-express slot which is as much as four times faster than AGP.
• Modern graphics adapters usually incorporate some memory right on the card to improve their performance. To further improve the performance of the video output, a second graphics accelerator card can be used in tandem with the graphics adapter.
• The Sound Card• Most PCs are typically equipped for multimedia. They can play
sounds, music, and speech. The sound card processes the information and outputs the signal to the speakers.
• The sound card plugs into a slot on the motherboard or is built right into the board. Many PCs now include a basic sound processor built into the motherboard and a card used for higher end sound and features are desired. With a basic sound card a microphone, speakers and an auxiliary sound source can be connected to it. More advanced cards support additional features such as surround sound.
• The Modem• The modem is a device that enables the PC to use a telephone
line to communicate with other PCs and connect to the Internet. The name comes from "MOdulation DEModulation".
• The modem plugs into a slot on the motherboard or is incorporated directly into the electronics of the motherboard. It converts data into signals that can be transmitted over the telephone line and receives data to convert back for the PC to use.
• The Mouse• The mouse is a user input device that enables you to
communicate with your PC. By moving the mouse and pressing the two or three buttons, you can highlight and select images on the screen to give directions to your PC. Some mice offer a wheel to aid in the scrolling of a window without having to move the mouse.
• A mouse is usually connected by a wire but wireless mice are also available. Wired mice may use a serial, PS/2 or a USB port. Other variations of mice available include the trackball and touchpad.
• The mouse detects movement either as a ball underneath the mouse rolls along your desk or by using a light inside the mouse and measuring the reflection from the desktop.
• The Keyboard• The keyboard is the primary user input device. It enables you to
communicate with your computer. While the mouse is also a fundamental device to control the PC, the keyboard goes one step further by allowing you to enter specific information as opposed to simply pointing and clicking.
• The keyboard connects to the computer through a wire, although wireless keyboards are also available. Variations of the classic keyboard include the addition of action specific buttons, most commonly for Internet features, and split keyboards which angle the two halves of the keyboard to reduce stress on your wrists as you type.
• The Network Interface Card• Most PCs are typically equipped for connecting to a network.
They can communicate with other PCs, printers or cable & DSL modems through their Network Interface Card (NIC). Ethernet adapter is a synonymous term and used interchangeably.
• The NIC plugs into a slot on the motherboard or is built right into the board. Many PCs now include a network interface built into the motherboard. Cards are typically rated for their speed capability of 10, 100 or 1,000 Mbps (mega bits per second. In the case of 1,000 Mbps, it is more correctly referred to as a Gigabit.