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) Market statistics.

Personal computer hardware

---

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

• Motherboard or system board with slots for expansion cards and holding parts including:
  • Central processing unit (CPU)
  • Random Access Memory (RAM) - for program execution and short term data storage, so the computer doesn't have to take the time to access the hard drive to find something. More RAM can contribute to a faster PC. RAM is normally removable by being in slots on the motherboard.
  • Basic Input-Output System (BIOS) or Extensible Firmware Interface (EFI) in newer computers
  • Buses :
    • PCI bus
    • PCI-E or AGP bus
    • ISA bus (outdated)
    • EISA bus (outdated)
    • USB
• Power supply - a case that holds a transformer, voltage control and 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
• 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
  • Floppy disk
  • Zip drive
  • USB Flash Drive
  • 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

More on [ Computer hardware ]

BBC News | Science/Nature | World Edition

Exploding star caught in the act
Wed, 21 May 2008 17:26:03 -0000
Astronomers capture and record the first moments when a massive star blows itself apart.
Call to settle ocean care dispute
Wed, 21 May 2008 19:15:19 -0000
Governments are urged to agree measures to protect oceans and the sea floor at a UN conservation meeting.
Sound 'cause of shadow spectacle'
Wed, 21 May 2008 15:07:23 -0000
Mysterious bands of shadow during an eclipse might be produced by sound pulses, a theory suggests.

NYT > Environment

New Trend in Biofuels Has New Risks
Wed, 21 May 2008 04:28:02 -0000
Many crops that could be used to make biofuels without driving up food prices are invasive species, scientists say.
A Busy Year as Tornadoes Wreak Havoc
Wed, 21 May 2008 05:16:02 -0000
Meteorologists who keep records for the National Oceanographic and Atmospheric Administration say that the United States is having its deadliest tornado season in a decade.
Report Charges Interference on Emissions
Tue, 20 May 2008 04:34:31 -0000
According to sworn depositions, the White House influenced the E.P.A. administrator’s decision to deny California’s request to limit tailpipe emissions.

ENN: Climate

Climate change having 'worldwide, widespread effects'
[BEIJING] Many physical and ecological systems are being affected by the world's warming climate, researchers say. Scientists from across the world applied statistical models to published data on changes in 829 physical systems and around 28,800 plant and animal systems —on both global and continental scales — some with data going back to 1970.
Population and Climate Change: Can We Talk?
ISTANBUL-The workshop I've been attending in this ancient city drew 31 people-ranging from a member of the British parliament to a Dutch women's rights advocate to a Hungarian environmentalist-to talk about whether it makes sense to bring population into the global debate on climate change.
Tropical Rainforests are Planet's Lungs
The resignation of Marina Silva as the environment minister of Brazil is a blow to the very future of the planet. Five years ago, she was appointed guardian of the Amazon but, in that time, she has fought an uphill battle against the loggers and ranchers of Brazilian agribusiness. Indeed, she often seemed a lone voice in the Brazilian government -- outvoted on the introduction of genetically modified grains, on the construction of a new nuclear power plant and on massive infrastructure projects, including two big hydroelectric dams and a major new road in the rainforest. She has finally quit, worn down by ill health and the appointment of a rival minister to speed the approval of energy projects.

L.A. Times - Environment

Pollution survey finds California beaches cleaner
Wed, 21 May 2008 11:20:00 -0700
Eco-friendly expo Green West opens
Wed, 21 May 2008 00:00:00 -0700
Environmentalists sue to broaden polar bear decision
Tue, 20 May 2008 13:38:00 -0700

National Geographic News

Tasmanian Devils Named Endangered Species
Wed, 21 May 2008 00:00:00 -0000
The feisty marsupial's new status comes in response to its decline from a mysterious cancer, the Tasmanian state government announced recently.
Amazon Indians Attack Official Over Dam Project
Wed, 21 May 2008 00:00:00 -0000
Waving machetes and clubs, painted Kayapo Indians attacked and may have slashed an official over a proposed dam that may displace them and ruin fishing grounds.
Supernova Caught Starting to Explode for First Time
Wed, 21 May 2008 00:00:00 -0000
An x-ray flash that signals the start of a stellar explosion could help astronomers predict supernovae and could boost the search for exotic phantom particles and ripples in space-time.

USDA - Natural Resources

Forest Service Maps and General Guides.
Topographic maps, specialty maps and brochures, national trails, roadless areas.
Plants Database
Classification, characteristics, invasive and noxious plants, alternative crops, distribution maps, fact sheets.
National Water Management Center
Direct assistance, information, and technology on water-related issues for natural resources conservation.

The Economist: The environment

Green pedicure
Mon, 19 May 2008 07:24:59 -0000
Footprints in carbon, nitrogen and waterCARBON footprints have become a widely accepted way to measure and describe humanity?s impact on the planet. But in principle, one can work out any kind of footprint. One?s turnip footprint would be the number of turnips (or root-vegetable equivalents) consumed in a lifetime. It wouldn?t be useful because it doesn?t capture anything that the world actually needs to know. That?s an important point when calculating a footprint: what is to be measured?A carbon footprint measures greenhouse gases produced by any activity. The father of the carbon footprint is the ecological footprint, which was introduced in the 1990s. It calculates the productive land and aquatic ecosystems needed to produce the resources and assimilate the wastes of any given human population. ...
Dead water
Thu, 15 May 2008 13:08:34 -0000
Too much nitrogen being washed into the sea is causing dead zones to spread alarmingly NEW life generally flourishes in the spring, unless it is marine life in the Gulf of Mexico. Every spring the coastal waters turn into a scene of devastation and death. Known as a ?dead zone?, this vast oxygen-depleted area extends along the coast between Louisiana and Texas.Hundreds of the world's coastal regions have dead zones. They mostly occur when spring rainfall gathers on land, makes its way into streams and rivers, and eventually tumbles down to the ocean. The rivers carry with them a cargo of nutrients, in particular nitrogen, from farms in the watershed. When this nitrogen reaches the sea it causes a brief frenzy of algal growth which depletes the water of oxygen. Fish, clams, shrimp, crabs, entire mussel reefs and other bottom-dwelling animals can be wiped out. ...
Days of disaster
Thu, 15 May 2008 13:08:34 -0000
Two natural disasters; two very different responses. We look first at the government's response to the earthquake in China, then at poor Myanmar?DON'T cry, don't cry. It's a disaster, and you've survived,? China's prime minister, Wen Jiabao, told weeping orphans in a town almost flattened by the country's worst natural disaster in more than 30 years. Mr Wen's awkward words may have done little to calm the bereaved children. But amid the huge destruction caused by the earthquake of May 12th, China's leaders thus far have scored some unusual public-relations successes.Hampered by poor weather (at least for the first day or two) and the blocking of mountain roads by landslides, Chinese troops have been struggling to rescue thousands of people buried in rubble and to bring aid to stricken communities across a wide area of the southwest on the edge of the Tibetan plateau. Three days after the disaster, officials put the number of dead at around 20,000, most of them in Sichuan Province north of the provincial capital, Chengdu. With many trapped, the toll could reach 50,000, the government said. ...

Reuters: Environment

Denmark seeks unity over Arctic claims
Wed, 21 May 2008 11:22:39 -0400
COPENHAGEN (Reuters) - Denmark called on Arctic coastal nations on Wednesday to avoid a scramble for the region's resources and urged all countries to abide by U.N. rules on territorial claims.
Queen goes green with world's largest wind turbine
Wed, 21 May 2008 11:41:41 -0400
ABERDEEN (Reuters) - Britain's Queen Elizabeth is going green by investing in the largest wind turbine in the world, her property company the Crown Estate said on Wednesday.
EU lawmakers call for faster climate change curbs
Wed, 21 May 2008 11:28:35 -0400
BRUSSELS (Reuters) - Global temperature rises should be kept well below the European Union's target of 2 degrees Celsius to avoid costly damage to people and their lifestyles, the European parliament said on Wednesday.

PR-inside.com News

After months of development sustainable business expert and environmental agency Envirowise is calling on UK businesses to try its new web-based environmental impact measurement tool.
Wed, 21 May 2008 17:02:32 -0000
(PR-inside.com) The Indicator comes pre-loaded with resource and waste costs across six of the UK's largest sectors including office, retail, food and drink, manufacturing, chemicals and construction. Alternatively, companies can input their own data on materials used and waste volumes produced if they have this information to hand. They can then make amendments to the figures online to see the resulting financial and environmental impacts. According to a recent survey1 74 per cent of 200 European companies questioned were not sure how to measure their environmental impact. This tool will help them do just that, claims Envirowise, as well as pointing them ..
Greenfield, PvT Capital join forces to clean up Chernobyl nuclear contamination in CIS radiation zones
Tue, 20 May 2008 13:10:13 -0000
(PR-inside.com) German bioenergy expert PvT Capital GmbH and Irish bioethanol developer Greenfield Project Management Ltd today announced their agreement to jointly develop Greenfield's proposed ethanol refineries in Belarus and to make this the first step in creating giant biomass refineries capable of producing a range of biofuels. PvT Capital's agreement to partner with Greenfield also brings on board the Center for Environmental Research (UFZ) of the world-renowned Helmholtz Association of Research Centers.. The plan will transform Greenfield's bioethanol facilities into multi-stage plants producing biodiesel, bioethanol, biogas and green electricity, with a relatively small amount of waste ash containing radioactive isotopes remaining to be ..
SILFAB SIGNS A SIX-YEAR CONTRACT WITH HYUNDAI HEAVY INDUSTRIES FOR HIGH QUALITY SOLAR-GRADE WAFERS SUPPLY
Mon, 19 May 2008 15:12:38 -0000
(PR-inside.com) Padova, May 15th, 2008 - Silfab S.p.A., the first Italian manufacturer of high quality (9N-) solar-grade polysilicon and wafers, today announced that it has signed a six-year ‘take or pay' contract to supply multi-crystalline wafers with high quality to Hyundai Heavy Industries Co., Ltd.(HHI). Under the terms and conditions of this Contract, Silfab will provide wafers over six-year commencing in Q4, 2009 through 2015. Franco Traverso, Chairman and CEO of Silfab, stated: 'Silfab is pleased of partnering with HHI that will be one of leading companies in photovoltaic business and produce the solar power generation systems having a high performance ..

NPR Topics: Environment

SUV Owners Ready for Something Smaller
Wed, 21 May 2008 13:00:00 -0400
As gas prices soar many owners of large SUVs are trading in their vehicles for smaller gas-sipping cars. They're finding that their big trucks aren't worth much as trade-ins.
Local Plants Give Sense of Place, Character
Tue, 20 May 2008 16:55:00 -0400
As budding horticulturists begin invading garden centers around the country, gardener Lisa Caprioglio talks with Michele Norris about the benefits of growing local plants.
Is Energy Independence a Pipe Dream?
Tue, 20 May 2008 13:00:00 -0400
With oil prices heading for $130 a barrel, phrases like "alternative fuels" are popping up more. But breaking our dependence on oil isn't a simple matter since the most promising alternatives are still in the early stages. We talk to people with an array of solutions.

UN News Centre - Environment, Shelter

Participants at UN-backed meeting agree to work towards rules on biosafety
Sat, 17 May 2008 00:00:00 -0500
More than 2,000 participants attending a week-long biosafety meeting that wrapped up yesterday have agreed to work towards legally binding rules for liability and redress for potential damage caused by the movements of genetically modified organisms (GMOs), the United Nations Environment Programme (UNEP) reports.
‘Billion Tree Campaign' blossoms to seven times its size, UN agency says
Tue, 13 May 2008 00:00:00 -0500
A grassroots campaign to plant trees around the globe has announced that it is raising its target from 1 billion trees to 7 billion trees, the United Nations announced today.
Thousands gather for meeting on UN-backed treaty on biosafety
Mon, 12 May 2008 00:00:00 -0500
More than 3000 participants from 147 countries have assembled in Bonn, the former German capital, for the start of a week-long meeting on how to improve their commitments to ensuring the safe use of modern biotechnology as outlined under a United Nations-backed treaty.

Environment

2. Climate Change, Growth, and Poverty
B-SPAN On April 15 and 16, 2008, the 2008 Poverty Reduction and Economic Management (PREM) Network Conference was held at World Bank Headquarters in Washington, D.C., to discuss the theme, Inclusive and Sustainable Growth. The Conference included more than 25 sessions on a variety of topics, such as the Banks economic policy, climate change, and good governance, among many others.
Will God or Man Play Dice with Nature? The
B-SPAN Discussions on climate change economics, policy, and related climateinduced disasters have so far neglected the possibility of catastrophic climate change. Climate scientists agree that though the probability is very low, climate change of cataclysmic proportions could occur and the effects would be nothing short of complete devastation. The event, Will God or Man Play Dice with Nature? The ‘Tail of Catastrophic Climate Change, held at the World Bank Headquarters on March 13th 2008 brought together a group of renowned economists and perspectives from the private sector, pubic policy, and development experts to discuss this issue. Hosted by the Global Facility for Disaster Reduction and Recovery, this event is part of a series designed to contribute ideas by prominent individuals such as Kenneth Arrow, Richard Posner, Thomas Schelling, John Seo, Martin Weitzman, and others on selected themes of the joint World Bank – UN Assessment on the economics of disasters.
60 Minutes with Nobel Laureate Kenneth J. Arrow
B-SPAN Climate change is one of the defining issues of our times. However, there is little consensus among economists on the issue of impacts of climate change, and discounting and uncertainty are two key reasons why. On March 27 2008, 1972 Nobel Laureate in Economics, Kenneth Arrow, and Professor Emeritus at Stanford University shared his views on discounting for projects that have payoffs in the deep and uncertain future. Thomas Schelling, 2005 Nobel Laureate in Economics, and Distinguished University Professor, University of Maryland participated by providing critical commentary on Arrows presentation. Hosted by the Global Facility for Disaster Reduction and Recovery, this event is part of a series designed to contribute ideas by prominent individuals such as Kenneth Arrow, Richard Posner, Thomas Schelling, John Seo, Martin Weitzman, and others on selected themes of the Assessment on the economics of disasters.

Subscribe to Computer_Hardware RSS feed