How to Buy a Laptop #5

Somewhat important: Optical drives. Most manufacturers offer laptops with rewritable DVD drives, which give you the most flexibility. Alternatively, you could purchase a notebook with a DVD-ROM/CD-RW drive, to save money.

Laptop shopping tips
Are you ready to buy a notebook? Here are our recommendations for specifications that will fit the needs of the average user.

A 2.0-GHz Core 2 Duo processor. For everyday work -- word processing, spreadsheets, e-mail -- you don't need the latest, greatest (read: "most expensive") processor, but thankfully, with the Core Duo, you get strong performance and great battery life. (Check latest prices.)
2GB or more of memory. Anything less will slow your work. The only new machines that still carry less than 2GB of RAM are netbooks. Upgrade to a 64-bit OS if you want to carry more than 3GB on your laptop.

Supplemental battery. If you want more time away from an outlet, buy a higher-capacity supplementary battery when you purchase the laptop, or buy a notebook that has a modular bay capable of holding a supplementary power pack. Secondary batteries usually cost between $99 and $200.

A 13.3-inch wide screen. A screen larger than 12.1 inches permits higher resolutions. Unless you're pinching pennies -- or you crave a tiny laptop -- bigger is usually better, especially on your eyes. (Compare prices for laptops with screens that are at least 14.1 inches in size.)
A 160GB hard drive. Even some netbooks that cost under $500 are bundling a 160GB hard drive (granted, they spin slowly at 4200 rpm). So if you can get a large hard drive in your unit, do so. And as tempting as a solid-state drive may sound, it's an expensive choice for relatively little storage capacity.

A touchpad pointing device. Pointing devices are a matter of taste. Most people, however, find a touchpad easier to use than a pointing stick. For people who can't decide between a touchpad and an eraserhead pointing device, some notebooks include both. If you buy one of these, make sure that it provides two sets of mouse buttons -- one for the touchpad and the other for the eraserhead -- so you don't have to stretch to reach.

Multiple USB ports. Many laptops now come with two or more USB 2.0 ports, useful for connecting more of the latest peripherals.

All-in-one design. Unless you need a lightweight notebook, opt for one with an internal bay for the optical drive. This design enables you to swap in other devices, such as an extra hard drive or a second battery.

Content by: PC World

How to Buy a Laptop #4

The specs explained
Before shopping for a laptop, consider how you'll be using it. If your primary goal is to get some word processing or spreadsheet work done while staying on top of e-mail, a netbook (priced at less than $500) will meet your needs. But a netbook does entail some sacrifices: a smaller processor, about 1GB of RAM, not much in the way of hard drive space, no optical drive, and (at biggest) a 10.2-inch screen. On the surface not much separates the netbooks from sexy lightweight notebooks, but the specs under the hood (and a big screen inside it) can inflate an ultraportable's price to as much as $2,000 more than a typical netbook.
Remember that most vendors let you custom-build and -price your own laptop by picking from a mind-boggling array of features, which gives you a lot of control over the final product. You may be able to afford a faster notebook by accepting a smaller, less-expensive hard drive or DVD-ROM/CD-RW drive, instead of a BD-ROM.

Unlike those on desktop PCs, only some of the components (such as memory and the hard drive) are upgradable; others (such as the graphics board) are permanent once they're installed at the factory. That's slowly changing, as some manufacturers begin to incorporate upgradable graphics. But take your time and pick only what you need. Following is a rough breakout of some configuration options.

Important consideration: Installed memory. The more installed memory your laptop has, the more applications you can run at once, and the better your machine will perform. Ease of access aside, upgrading memory in a notebook is a bit trickier than with a desktop, so buy as much memory pre-installed as you can afford. Laptops with 2GB of RAM are optimal. If you're running Windows Vista on a laptop, consider upgrading to 3GB of RAM (or more if your notebook uses a 64-bit version of the OS).

Important consideration: Processor. The CPU determines how quickly a notebook runs applications and performs on-screen tasks. Core Duo and Core 2 Duo processors are good choices for speedy processing. Atom processors appear only in budget-friendly netbooks, so plan according to your needs. (Check the latest prices for recommended notebooks.)
Important consideration: Screen size. The specified size of a laptop's LCD screen represents a diagonal measurement. The larger the screen, the higher the maximum resolution and the more information you can view at once. At this point, most notebooks are wide-screen models; if you want a laptop with a standard-aspect screen you'll have to search a bit, but they are still available. The aspect ratio seen on some newer 16-inch laptop screens offers the ideal resolution for viewing high-definition movies on the go. (Compare laptops with recommended screen sizes.)
Important consideration: Screen coating. A laptop's LCD panel is only as good as it looks when you look into it. Can you see text and images clearly when you're viewing them in broad daylight? Many notebooks that look sharp on store shelves (thanks to their extra-glossy coatings) may be tough to work with outdoors or in a coffee shop. So keep in mind not only how you plan to use your notebook, but where you want to use it.

Somewhat important: Hard drive. The larger the hard drive, the more data you can keep on your laptop. Most cheap netbooks offer 80GB drives at this point, so why not give yourself a little room to grow? If you plan to work with databases, spreadsheets or digital photo or video files, opt for a large drive. Be sure to find out the hard drive's speed, too. Older, slower drives run at 4200 rpm, and most current drives clock in at 5400 rpm; but a 7200-rpm model will offer better speed in data-read-intensive tasks.

Somewhat important: Expansion bays. The more expansion bays your laptop has, the more options you'll have for switching in new optical drives or other storage drives. But switching drives takes time, and modular components aren't as common as they used to be. As laptops gravitate toward flush form factors and unibody designs, may find that your only practical option is to lug around external drives that plug in through USB ports.

Content by: PC World

How to Buy a Laptop #3

Optical and other drives: Most manufacturers offer laptops with rewritable DVD drives. But now that Blu-ray Disc has triumphed over HD DVD in the high-definition format wars, more notebooks are being configured with Blu-ray drives. If you need a floppy drive for some reason, you can buy a USB add-on drive for 20 bucks.

Hard drive: Even inexpensive netbooks now come with 60GB hard-disk drives (HDDs). Most all-purpose machines offer hard drives in the range of 200GB to 320GB, and ultraportables now pack solid-state drives (SDDs). Though SDDs are faster and lighter than HDDs, their capacities are considerably lower (maxing out at around 128GB) at a significantly higher cost. In today's market, an SSD adds about $1,000 to a laptop's price tag over the cost of a machine with similar specs equipped with a larger-capacity platter-based drive. So, you need to balance speed and weight against price and storage capacity. Whichever choice you make, you'll find that hard-drive space fills up quickly, so you might want to consider buying a portable external drive as well.

Weight and bay design: Laptops range from 15-pound desktop replacement monsters to ultraportable lightweights that rely on external drives to come in at under 3 pounds. One-bay notebooks balance features and weight. Some laptops continue to offer the optical drive as a modular device, so you can swap it out for a second hard drive or a second battery.
When making a purchase, however, keep in mind that you should consider the weight not only of the laptop but also of the AC adapter, the extra batteries, any external modules, and their cables. Ultraportable notebooks have lightweight adapters, but they can weigh almost as much as a full-size notebook if you have to carry an external optical drive, too.

When you return to your desk, you can snap most laptops onto an extra-cost docking station or port replicator (prices range from $100 to $500). Doing so saves you from repeatedly having to plug in and unplug an external monitor, keyboard, mouse and other desktop peripherals.
Communications: Few laptops come with a full set of legacy ports anymore. Serial ports are as rare as Bigfoot sightings at this point, as are PS/2 ports (for a mouse or keyboard). Most notebooks still have one PC Card slot, though many now offer an ExpressCard slot as well. With new GPUs, many notebooks -- and even some netbooks -- now offer HDMI outputs.
Most laptops have at least two USB 2.0 ports; many offer four, and some up to six. A majority of notebooks include a four-pin FireWire (IEEE 1394) port for connecting an external drive or a digital-video camcorder. Others now include eSATA ports for high-speed data transfers.
Built-in Ethernet now comes standard on all portables, with many models carrying gigabit Ethernet. Many laptops also have built-in Bluetooth. Notebooks using the Intel Core Duo or Core 2 Duo processors -- or AMD's Turion 64 X2 processor -- include Intel's wireless 802.11a/b/g chip set.

Some laptops come with built-in wireless broadband wide-area networking, enabling them to access, for example, Verizon Wireless's EvDO Broadband Access service.
Most also include a multiformat flash card reader, which can read Secure Digital, MultiMediaCard, Memory Stick, Memory Stick Duo and xD formats.

Content by: PC World

How to Buy a Laptop #2

System memory: Unless you're buying on the cheap, a new laptop generally includes 2GB of system memory. Many notebooks today are available with 3GB of RAM or more. Before electing to upgrade to more RAM than that, be sure to check which version of Windows your new notebook uses. A 32-bit OS can't efficiently use more than 3GB of RAM. A 64-bit version can go higher. Outfitting your laptop with more RAM at the time you buy it is convenient and helps you extend its useful life.

Graphics memory: Portables can have either of two different types of video chip sets: dedicated video (which means a separate pre-installed graphics card) or integrated graphics. Dedicated video chip sets come from nVidia and ATI/AMD, whereas integrated graphics are typically from Intel. If you intend to use your laptop for even casual gaming, make sure that it has memory dedicated to graphics use, rather than relying on graphics that pull from main memory. Gamers need advanced 3-D graphics chips, along with 512MB of dedicated graphics memory. High-end desktop-replacement notebooks have sophisticated desktop graphics capabilities, as well; in the past, integrated graphics would work just fine for business purposes, but Windows Vista demands a more powerful graphics subsystem.

Some laptops now offer Scalable Link Interface (SLI), which provides a means to run multiple graphics chips in one machine. Hybrid SLI, a technology offered by nVidia, involves two GPUs operating within a single notebook. The most basic version of Hybrid SLI already exists on Apple's new MacBook Pro laptop and on a couple of notebooks from Sony's Vaio line. With these machines you toggle between a high-powered discrete GPU for graphics-intensive work or play and an integrated GPU on the motherboard for low-demand graphics. A second implementation of Hybrid SLI will allow an integrated GPU, like nVidia's GeForce 9400M GS, to work in tandem with a discrete GPU for greater performance when needed -- and then downshift to a lower-power mode when it isn't.

Screen: Some laptop screens continue to get bigger -- and most have gone wide, too, enabling you to view spreadsheets or movies with ease. But other screens have gotten significantly smaller to accommodate all sorts of road-ready computing. Price is no longer much of a deterrent for any of these choices. Even budget shoppers can afford the luxury of high-resolution color: Portables with 14.1-inch and 15.4-inch wide screens now cost well under $1,000. Most notebook manufacturers offer laptops with wide-screen panels, to permit better side-by-side document viewing as well as to display films at their proper aspect ratio. These days, netbooks come equipped with screens as large as 10.2 inches. Ultraportable notebooks max out at 13.3 inches. And anything between 13.3 and 17 inches qualifies as an all-purpose machine -- a laptop that still fits in your bag. The new middle ground for all-purpose screens is 16 inches because screen of this size can display a true 1080p (1920-by-1080-pixel resolution) picture.

Battery: Laptop battery life continues to improve. In PC World's tests, laptops using a Core Duo or Core 2 Duo processor average roughly 3.5 hours on one battery charge. Keep in mind that manufacturers may improve their times by taking steps such as turning off wireless receivers, which tend to consume a lot of power. Also, check to see if the manufacturer's stated battery-life numbers are for its regular or extended-life battery -- the latter kind of battery can last up to twice as long as a regular one. And remember that, in general, lighter laptops tend to have longer battery lives than big desktop-replacement notebooks do.

Keyboard and pointing device: Though you can get accustomed to almost any laptop keyboard, it's best to try before you buy. Thin-and-light notebooks usually have smaller-than-average keys spaced more closely than the keys on a desktop-replacement model, and their layouts may differ from a standard keyboard's. If you have largish hands, be aware that an ultraportable's keyboard may be difficult to use.

You probably won't be invited to choose between eraserhead and trackpad pointing devices; if you have a preference, look for manufacturers that use the pointing device you prefer on most of their products. A better option: Buy a USB mouse designed for laptops. It's a small investment, and your hands will thank you for it.

Content by:

How to Buy a Laptop

Introduction
The most highly evolved species of computer, the laptop (aka notebook) computer allows you to work without being tethered to an office. Portability and good performance make laptop PCs an essential part of the daily lives of millions of people, from college students to business travelers. Even the least-expensive of today's laptops are well-equipped for everyday work.
The big picture: There are more laptop choices than ever. We'll identify and discuss the available options -- including screen size, weight, battery life and communications ports.

The big picture
If you've ever shopped for a laptop, you know that the factors to consider go far beyond performance and connections. Notebook buyers have to think about such additional variables as size, weight, screen dimensions, battery life and keyboard quality -- plus options such as built-in wireless.
Key features
Processor: Intel's dual-core processors have helped laptops gain ground in the power department. In PC World tests, laptops using these dual-core processors performed considerably faster than laptops using single-core processors, particularly when multitasking. In newer notebooks you may see references to Core Duo, Core 2 Duo and Core 2 Extreme, which represent steps up in computing power for laptops.
Some notebooks use AMD's Athlon Turion 64 X2 dual-core processor, which also supports improved performance. The Turion 64 X2 and the Core 2 Duo both provide 64-bit support, which will become increasingly useful as more 64-bit applications reach the market.
Low-end laptops offer Intel's Celeron M processor, which is generally not as speedy as the Core 2 Duo processors. And down below low-end are the new mobile processors that appear in netbooks (or mini-notebooks) -- sub-$500 machines that run on low-power, low-cost 1.6-GHz Atom CPUs.

Content by: PC wolrd

Computer history

An Illustrated History of Computers Part 1
___________________________________
John Kopplin © 2002
The first computers were people! That is, electronic computers (and the earlier mechanical computers) were given this name because they performed the work that had previously been assigned to people. "Computer" was originally a job title: it was used to describe those human beings (predominantly women) whose job it was to perform the repetitive calculations required to compute such things as navigational tables, tide charts, and planetary positions for astronomical almanacs. Imagine you had a job where hour after hour, day after day, you were to do nothing but compute multiplications. Boredom would quickly set in, leading to carelessness, leading to mistakes. And even on your best days you wouldn't be producing answers very fast. Therefore, inventors have been searching for hundreds of years for a way to mechanize (that is, find a mechanism that can perform) this task.

This picture shows what were known as "counting tables" [photo courtesy IBM]

A typical computer operation back when computers were people.
The abacus was an early aid for mathematical computations. Its only value is that it aids the memory of the human performing the calculation. A skilled abacus operator can work on addition and subtraction problems at the speed of a person equipped with a hand calculator (multiplication and division are slower). The abacus is often wrongly attributed to China. In fact, the oldest surviving abacus was used in 300 B.C. by the Babylonians. The abacus is still in use today, principally in the far east. A modern abacus consists of rings that slide over rods, but the older one pictured below dates from the time when pebbles were used for counting (the word "calculus" comes from the Latin word for pebble).

A very old abacus

A more modern abacus. Note how the abacus is really just a representation of the human fingers: the 5 lower rings on each rod represent the 5 fingers and the 2 upper rings represent the 2 hands.
In 1617 an eccentric (some say mad) Scotsman named John Napier invented logarithms, which are a technology that allows multiplication to be performed via addition. The magic ingredient is the logarithm of each operand, which was originally obtained from a printed table. But Napier also invented an alternative to tables, where the logarithm values were carved on ivory sticks which are now called Napier's Bones.

An original set of Napier's Bones [photo courtesy IBM]

A more modern set of Napier's Bones
Napier's invention led directly to the slide rule, first built in England in 1632 and still in use in the 1960's by the NASA engineers of the Mercury, Gemini, and Apollo programs which landed men on the moon.

A slide rule
Leonardo da Vinci (1452-1519) made drawings of gear-driven calculating machines but apparently never built any.

A Leonardo da Vinci drawing showing gears arranged for computing
The first gear-driven calculating machine to actually be built was probably the calculating clock, so named by its inventor, the German professor Wilhelm Schickard in 1623. This device got little publicity because Schickard died soon afterward in the bubonic plague.

Schickard's Calculating Clock
In 1642 Blaise Pascal, at age 19, invented the Pascaline as an aid for his father who was a tax collector. Pascal built 50 of this gear-driven one-function calculator (it could only add) but couldn't sell many because of their exorbitant cost and because they really weren't that accurate (at that time it was not possible to fabricate gears with the required precision). Up until the present age when car dashboards went digital, the odometer portion of a car's speedometer used the very same mechanism as the Pascaline to increment the next wheel after each full revolution of the prior wheel. Pascal was a child prodigy. At the age of 12, he was discovered doing his version of Euclid's thirty-second proposition on the kitchen floor. Pascal went on to invent probability theory, the hydraulic press, and the syringe. Shown below is an 8 digit version of the Pascaline, and two views of a 6 digit version:

reference
http://www.computersciencelab.com/ComputerHistory/History.htm