Hardware

An exploded view of a modern personal computer and peripherals:

1. Scanner
2. CPU (Microprocessor)
3. Primary storage (RAM)
4. Expansion cards (graphics cards, etc)
5. Power supply
6. Optical disc drive
7. Secondary storage (Hard disk)
8. Motherboard
9. Speakers
10. Monitor
11. System software
12. Application software
13. Keyboard
14. Mouse
15. External hard disk
16. Printer

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 in expansion 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 expansion bus. 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.

[edit] 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.

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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 than subnotebooks, 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 original EEE PC.

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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.

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Things We Hate About Apple

It's high time we unloaded on the high-and-mighty Mac maker.
Narasu Rebbapragada and Alan Stafford, PC World

The company formerly known as Apple Computer and now called simply Apple, Inc. is unique in many ways--including in its ability to drive even folks who admire it positively batty. It makes great products (usually), yet its secretiveness about them borders on paranoia, and its adoring fans can be incredibly irritating. Of course, its fans have to put up with some irritations, too: Simply being a member of the club still means you must endure unending jabs from the other side of the socio-political-techno aisle. But do they have to wear their suffering as a badge of honor?

Today, we--that's us, Narasu and Alan, veteran Mac users both--are going to get some stuff off our chests. We've enumerated ten things we hate about Apple (or its followers, or simply about the experience of using its products). But in the interest of fair play (not to be confused with FairPlay, Apple's DRM technology) we're also publishing another list--Ten Things We Love About Apple.

Use the Comment link at the end of this article to add your own gripes about Apple--or to defend it.

And so, with protective helmets in place, off we go:

1: Free Speech, Anyone?
Even if you're no Apple fan, this particular issue might not rise to the top of your own personal gripe list--but hey, we're journalists. So sue us.

Er, that's probably not the right turn of phrase to use, considering that in December 2004, Apple filed a lawsuit against the AppleInsider, O'Grady's PowerPage, and Think Secret Web sites for posting information about upcoming technologies that Apple had shared with outsiders under nondisclosure agreements. In the case of O'Grady, the news was of a FireWire interface for GarageBand. In the words of O'Grady himself: "yawn."

Apple pressured the sites to reveal their sources, and even worse, pressured the sites' ISPs. In May 2006, a California court said no way, ruling that online journalists enjoy the same First Amendment rights as "legitimate" offline journalists. Seems silly in today's world, doesn't it? Recently, the court ordered Apple to pay the sites' legal fees--about $700,000.

2. More Secretive Than Homeland Security
Those feds are secretive, but they're no match for Apple reps' infuriating stock answer: "We don't comment on future product plans." Being an Apple adherent means never knowing for sure if the shiny new MacBook or iPod you just bought is about to be rendered obsolete by a Steve Jobs keynote.

Of course, Apple is merely the most famous secretive Silicon Valley company, not the only hush-mouthed one. And tight lips make for explosive buzz when the company does decide to drop a bombshell. But contrast Apple's secrecy with Microsoft's lack thereof--Bill Gates, Steve Ballmer, and company love to talk about their company's upcoming products, and they still get their fair share of buzz. Even though many of those plans have a tendency to not actually come true.

3. Ain't Too Proud to Blame
When Apple shipped iPods containing a worm last year, instead of issuing a humble mea culpa, Apple took a swipe at Microsoft, saying, "As you might imagine, we are upset at Windows for not being more hardy against such viruses, and even more upset with ourselves for not catching it." As you can imagine, that didn't fly with security experts. How about an apology to the folks who were unlucky enough to buy the infected iPods, period?

4. iHate iAnything
Apple first floated the idea of product names with a leading lowercase letter in 1994 with eWorld, an ill-conceived online service that went belly-up after a year and a half. But when it introduced the original iMac in 1998, it hit on a phenomenal success--and prompted hundreds of third-party manufacturers to follow with sickeningly cute Bondi Blue products with names that also began with a lowercase "i." Now dozens of Apple and third-party product names begins with "i." Their manufacturers are all jumping on the bandwagon, hoping that a single letter will sway us to buy their stuff. Meanwhile, you can't even start sentences with the products' names.

Is it any wonder that we're inclined to like Apple TV in part because it turned out not to be iTV? Or that we're kind of sorry that Apple was able to strike a deal with Cisco to share the name iPhone?

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Engineered bacteria become the first living computers

cientists have built the first living computer and tasked it with solving an important problem: flipping pancakes.

Researchers genetically engineered the bacterium E. coli to coax its DNA into computing a classic mathematical puzzle known as the burned pancake problem. Molecules of DNA have the natural ability to store and process information, and scientists have been performing computations with bare DNA molecules in lab dishes since the mid-1990s. But the new research, reported online in the Journal of Biological Engineering, is the first to do DNA computation in living cells.

“Imagine having the parallel processing power of a million computers all in the space of a drop of water,” says Karmella Haynes, a biologist at Davidson College in North Carolina. “It’s possible to do that because cells are so tiny and DNA is so tiny.”

While the potential computational power of programmed bacteria is immense, the DNA-computation system that Haynes and her colleagues designed can only solve problems by flipping and sorting data. It doesn’t have the open-ended computing flexibility of a laptop computer or even a solar-powered calculator, so the bacteria can only handle a limited set of mathematical problems. “We’re not going to have bacteria running iPods just yet,” Haynes says.

Other kinds of DNA computation are possible, though. Researchers in Israel recently designed DNA molecules that could compute games of tic-tac-toe, for example. “I liken this to where video games were when Pong first came out,” says Jeffrey Poet, a mathematician at Missouri Western State University in St. Joseph, Mo., and member of the research team.

The burned pancake problem sounds deceptively simple. Start with a stack of pancakes of varying sizes burned on one side, and try to get the pancakes into order from largest to smallest — all burned side down — through a series of flips. The figurative spatula can flip at any point in the stack, but has to include all the pancakes above. The question mathematicians try to answer is, for a given number of pancakes starting in a random orientation, what’s the smallest number of flips necessary to put the pancakes in order?

It’s the sort of brain teaser that mathematicians love to crack, but it’s also a metaphor for an important problem in computer science — sorting large amounts of data into the right order by repeatedly flipping chunks of data. Knowing the minimum number of flips necessary will tell programmers when their software has been fully optimized to sort the data as quickly as possible.

As the number of pancakes increases, solving this problem quickly becomes very hard. There’s no equation that will give the correct answer; it is necessary to explore all the possible configurations of the stack of pancakes. For six pancakes, there are 46,080 configurations. For 12 pancakes, there are about 1.9 trillion.

“These problems get so immense that even having a huge network of computers is not enough,” Haynes says. Because the number of bacteria in a colony grows exponentially, a single bacterium engineered to perform the flipping problem in its DNA will soon become several billion or trillion little bacterial computers. Each bacterium in the colony can then compute a separate flipping scenario.

The flipping is done by an enzyme taken from the salmonella bacterium. When salmonella invades a body, the person’s immune system learns to recognize a certain protein on the bacterium’s surface. By flipping a segment of its DNA — which involves snipping out a length of the stringlike molecule, turning that snippet around and reattaching it backward — salmonella can switch to a different version of this protein that the person’s immune system doesn’t recognize, thus evading attack.

Haynes and her colleagues inserted this enzyme, called Hin recombinase, into E. coli. The enzyme could then flip segments of E. coli’s DNA that are marked by genetic flags. The researchers designed these segments so that, when lined up in the correct order like pancakes stacked from biggest to smallest (burned side down, of course), the DNA spells out the code for a gene that gives the bacterium resistance to an antibiotic. That way, applying the antibiotic to the colony of engineered bacteria killed all of the bacteria that had not yet solved the puzzle. Only those that had “stacked their pancakes” would survive. Measuring how long it took the bacteria to reach the solution indicated how many flips were required.

“It’s a neat idea,” comments Lloyd Smith, a bioanalytical chemist at the University of Wisconsin–Madison who has done research on DNA computation. But the challenge for this technique, as for the entire field of DNA computation, will be scaling it up to solve larger problems, Smith says. “One question is how you program a living cell to do something, the other question is how well it scales.”

In this experiment, the engineered bacteria computed the equivalent of two stacked pancakes as a proof of concept, but Haynes says the researchers are now scaling it up to work for more pancakes. The researchers are also designing the bacteria to light up with a green fluorescent protein upon solving the puzzle, and the team is adapting the technique to work for other, related math problems.

"We’re right at the beginning,” Poet says. “We’re trying to understand what’s possible.”

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How to avoid getting your information stolen via wireless connections

Yesterday, I wrote about how the FBI is warning us that personal details can be stolen (i-jacked) when using public computers. This occurs using crimeware, previously installed on a public computer, logs the keys you are stroking and sends the information (electronically) to criminals.

It can be dangerous to look at any of your online financial information on these (public access) machines.

When writing about this phenomenon, I remembered that even using your personal computer at a public place with a wireless connection can expose a person's personal and sometimes, financial details.

Just the other day, Martin Bosworth, over at Consumer Affairs, wrote an excellent piece covering this danger, where he stated:

Sending unencrypted information over any unfamiliar network can turn your computer into an open book -- with pages full of your personal information.

Many of these connections are appear to be legitimate connections because they are spoofed (camouflaged to appear as if they are a trusted connection).

Spoofing a connection, or site isn't very hard to do. They simply copy and transpose pictures and statements (words) from legitimate sites to their own. The Artists Against website has a portal, where you can see fake websites that are up and running on the Internet, here.

Martin's article contains some excellent tips on how to navigate the murky waters of public hot spots, safely.

They can be viewed, here.

Interestingly enough, wireless technology, isn't only used to compromise individuals. In the recent TJX data breach, where some are saying 200 million records were stolen since 2003, reports are saying the data was stolen, using wireless technology.

It's being reported that this was accomplished from a car with a laptop. Driving around with a laptop, using other people's wireless connections, is sometimes referred to as "war-driving," which is my new word for the day.

Joseph Pereira (Wall Street Journal) wrote about this (courtesy of the Northwest Florida Daily News), here. Selengkapnya...