Wednesday, May 9, 2007

 

Computer hardware


Computer hardware
From Wikipedia, the free encyclopedia


Computer hardware is the physical part of a computer, including the digital circuitry, as distinguished from the computer software that executes within the hardware. The hardware of a computer is infrequently changed, in comparison with software and data, which are "soft" in the sense that they are readily created, modified or erased on the computer. Firmware is a special type of software that rarely, if ever, needs to be changed and so is stored on hardware devices such as read-only memory (ROM) where it is not readily changed (and is therefore "firm" rather than just "soft").


Most computer hardware is not seen by normal users. It is in embedded systems in automobiles, microwave ovens, electrocardiograph machines, compact disc players, and other devices. Personal computers, the computer hardware familiar to most people, form only a small minority of computers (about 0.2% of all new computers produced in 2003). See Market statistics.

Personal computer hardware

A typical Personal computer consists of a case or chassis in desktop or tower shape and the following parts:

Internals of typical personal computer

Typical Motherboard found in a computer



Motherboard or system board with slots for expansion cards and holding parts
Central processing unit (CPU)
Computer fan - used to cool down the CPU
Random Access Memory (RAM) - for program execution and short term data storage, so the computer does not have to take the time to access the hard drive to find the file(s) it requires. More RAM will normally contribute to a faster PC. RAM is almost always removable as it sits in slots in the motherboard, attached with small clips. The RAM slots are normally located next to the CPU socket.
Basic Input-Output System (BIOS) or Extensible Firmware Interface (EFI) in some newer computers
Buses
PCI
PCI-E
USB
HyperTransport
CSI (expected in 2008)
AGP (being phased out)
VLB (outdated)
ISA (outdated)
EISA (outdated)
Power supply - a case that holds a transformer, voltage control, and (usually) a cooling fan
Storage controllers of IDE, SATA, SCSI or other type, that control hard disk, floppy disk, CD-ROM and other drives; the controllers sit directly on the motherboard (on-board) or on expansion cards
Video display controller that produces the output for the computer display. This will either be built into the motherboard or attached in its own separate slot (PCI, PCI-E or AGP), requiring a Graphics Card.
Computer bus controllers (parallel, serial, USB, FireWire) to connect the computer to external peripheral devices such as printers or scanners
Some type of a removable media writer:
CD - the most common type of removable media, cheap but fragile.
CD-ROM Drive
CD Writer
DVD
DVD-ROM Drive
DVD Writer
DVD-RAM Drive
BD
BD-ROM Drive
BD Writer
Floppy disk
Zip drive
USB flash drive AKA a Pen Drive, memory stick
Tape drive - mainly for backup and long-term storage
Internal storage - keeps data inside the computer for later use.
Hard disk - for medium-term storage of data.
Disk array controller
Sound card - translates signals from the system board into analog voltage levels, and has terminals to plug in speakers.
Networking - to connect the computer to the Internet and/or other computers
Modem - for dial-up connections
Network card - for DSL/Cable internet, and/or connecting to other computers.
Other peripherals

In addition, hardware can include external components of a computer system. The following are either standard or very common.

Wheel Mouse
Input or Input devices
Text input devices
Keyboard
Pointing devices
Mouse
Trackball
Gaming devices
Joystick
Gamepad
Game controller
Image, Video input devices
Image scanner
Webcam
Audio input devices
Microphone
Output or Output devices
Image, Video output devices
Printer Peripheral device that produces a hard copy. (Inkjet, Laser)
Monitor Device that takes signals and displays them. (CRT, LCD)
Audio output devices
Speakers A device that converts analog audio signals into the equivalent air vibrations in order to make audible sound.
Headset A device similar in functionality to computer speakers used mainly to not disturb others nearby.

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by dayatna at 5:13 AM |

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