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I feel that it is important for the reader to realize how much technology has improved and made life easier over the past couple decades.
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==History==
==History==
{{main|History of laptops}}
{{main|History of laptops}}
Laptops have grown (or have grown less in size) and become more sophisticated over the years.
Laptops have grown (or have grown less in size) and become more sophisticated over the years. The size of laptop today is very minute compared to the computers in the past. Before, they used to weigh 30 tons and fill up a room, then, came the desktop, and now the laptop. Hmmm, What will be next?


==Types==
==Types==

Revision as of 00:24, 25 April 2008

An ultraportable IBM X31 with 12" screen on an IBM T43 Thin & Light laptop with a 14" screen
HCL's $329 miniature notebooks with 6" TFT touchscreens launched in India on January 29, 2008.

A laptop computer, or simply laptop (also notebook computer, notebook and notepad) is a small mobile computer, which usually weighs 2-18 pounds[citation needed] (around 1 to 8 kilograms[citation needed]), depending on size, materials, and other factors.

Laptops usually run on a single main battery or from an external AC/DC adapter that charges the battery while also supplying power to the computer itself. Many computers also have a 3 volt cell to run the clock and other processes in the event of a power failure.

Laptops contain components that are similar to their desktop counterparts and perform the same functions, but are miniaturized and optimized for mobile use and efficient power consumption, although typically less powerful for the same price. Laptops usually have liquid crystal displays and most of them use different memory modules for their random access memory (RAM), for instance, SO-DIMM in lieu of the larger DIMMs. In addition to a built-in keyboard, they may utilize a touchpad (also known as a trackpad) or a pointing stick for input, though an external keyboard or mouse can usually be attached.

History

Main article: History of laptops

Laptops have grown (or have grown less in size) and become more sophisticated over the years. The size of laptop today is very minute compared to the computers in the past. Before, they used to weigh 30 tons and fill up a room, then, came the desktop, and now the laptop. Hmmm, What will be next?

Types

Mainstream

Laptops weighing between 5 and 7 lb (2.3–3.2 kg) with a screen size of 14.1 or 15.4 inches (35 or 39 cm) diagonally.

Desktop replacement computers

Main article: Desktop replacement computer

Powerful laptops meant to be mainly used in a fixed location and infrequently carried out due to their weight and size; the latter provides more space for powerful components and a big screen, usually measuring 17–20 inches (43–51 cm). Desktop replacements tend to have limited battery life, rarely exceeding three hours, because the hardware is not optimized for efficient power usage. Sometimes called a luggable laptop. An example of a desktop replacement computers are gaming notebooks, which are designed to handle 3D graphic-intensive processing for gamers.

Thin-and-light

Main article: Subnotebook

Laptops weighing typically between 4.6 and 6 lb (1.8–2.7 kg) and a screen of 12 to 14 inches (30–35 cm) diagonally.

Parts

2.5" hard disk drive

Most modern laptops feature 12 inch (30 cm) or larger active matrix displays with resolutions of 1024×768 pixels and above, and have a PC Card (formerly PCMCIA) or ExpressCard expansion bay for expansion cards. Internal hard disks are physically smaller—2.5 inch (60 mm)—compared to the standard desktop 3.5 inch (90 mm) drive, and usually have lower performance and power consumption. Video and sound chips are usually integrated. This tends to limit the use of laptops for gaming and entertainment, two fields which have constantly escalating hardware demands.[1] However, higher end laptops can come with dedicated graphics processors, such as the Dell Inspiron E1505 and E1705, which can be bought with an ATI Mobility Radeon X1300 or similar or the MacBook Pro which comes standard with an nVidia 8600M GT. These mobile graphics processors tend to have less performance than their desktop counterparts, but this is because they have been optimized for lower power usage.

There is a wide range of laptop specific processors available from Intel (Pentium M, Celeron, Intel Core and Intel Core 2) and from AMD (Athlon, Turion 64, and Sempron) and also from VIA (C3 and C7-M). Motorola and IBM developed and manufactured the chips for the former PowerPC-based Apple laptops (iBook and PowerBook). Generally, laptop processors are less powerful than their desktop counterparts, due to the need to save energy and reduce heat dissipation. However, the PowerPC G3 and G4 processor generations were able to offer almost the same performance as their desktop versions, limited mostly by other factors, such as the system bus bandwidth; recently, though, with the introduction of the G5s, they have been far outstripped. At one point, the Pismo G3, at up to 500 MHz, was faster than the fastest desktop G3 (then the B&W G3), which ran at 450 MHz.

Some parts for a modern laptop have no corresponding part in a desktop computer. For example, current models use lithium ion and more recently lithium polymer batteries, which have largely replaced the older nickel metal-hydride technology. Typical battery life for most laptops is two to five hours with light-duty use, but may drop to as little as one hour with intensive use. Batteries gradually deteriorate over time and eventually need to be replaced in one to five years, depending on the charging and discharging pattern.

Laptops typically use SODIMMs, as shown here.

Docking stations became another common laptop accessories in the early 1990s. They typically were quite large and offered 3.5" and 5.25" storage bays, one to three expansion slots (typically AT style), and a host of connectors. The mating between the laptop and docking station was typically through a large, high-speed, proprietary connector. The most common use was in a corporate computing environment where the company had standardized on a common network card and this same card was placed into the docking station. These stations were very large and quite expensive. As the need to additional storage and expansion slots became less critical because of the high integration inside the laptop itself, the emergence of the Port Replicator as a major accessory commenced. The Port Replicator was often a passive device that simply mated to the connectors on the back of the notebook and allowed the user to quickly connect their laptop so VGA, PS/2, RS-232, etc. devices were instantly attached. As higher speed ports like USB and Firewire became commonplace, the Port Replication was accomplished by a small cable connected to one of the USB 2.0 or FireWire ports on the notebooks. Wireless Port Replicators followed.

Virtually all laptops can be powered from an external AC converter. This device typically adds half a kilogram (1 lb) to the overall "transport weight" of the equipment.

A pointing stick or touchpad is used to control the position of the cursor on the screen. The pointing stick is usually a rubber dot that is located between the G, H and B keys on the laptop keyboard. To navigate the cursor, pressure is applied in the direction intended to move. The touchpad is touch-sensitive and the cursor can be navigated by moving the finger on the pad.

Intel, Asus, Compal, Quanta and other laptop manufacturers have created Common Building Block standard for laptop parts.

Disadvantages

Parts standardization and compatibility issues

Current compatibility problems in the laptop trade are reflective of the early era of personal computer hardware, when there were many different manufacturers, each and every one of them having their own connectivity and mounting systems and incompatibility was the norm. While there are accepted world standards of form factors for all the peripherals and add-in PC cards used in the desktop computers, there are still no firm worldwide standards relating to today's laptops' internal form factors, such as supply of electric voltage, motherboard layouts, internal adapters used in connecting the optical drive, LCD cable, keyboard and floppy drive to the main board. Most affected by this are users uneducated in the relevant fields, especially if they attempt to connect their laptops with incompatible hardware or power adapters.

Some parts, such as hard drives and memory are commodity items and are interchangeable. However, other parts such as motherboards, keyboards, and batteries are proprietary in design and are only interchangeable within a manufactures brand and/or model line.

A significant point to note is that the vast majority of laptops on the market are manufactured by a small handful of Original Design Manufacturers (ODM).[1] The ODM matters more than the Original Equipment Manufacturer (OEM). Major relationships include:

  • Quanta sells to (among others) HP/Compaq, Dell, Toshiba, Sony, Fujitsu, Acer, NEC, Gateway and IBM - note that Quanta is currently (as of August, 2007) the largest manufacturer of notebook computers in the world
  • Compal sells to Toshiba, HP/Compaq, Acer, and Dell
  • Wistron sells to HP/Compaq, Dell, IBM, NEC, and Acer
  • Arima sells to HP/Compaq, NEC, and Dell
  • Uniwill/ECS sells to IBM, Fujitsu, and Dell
  • Asus sells to Apple (iBook), Sony, and Samsung
  • Inventec sells to HP/Compaq, Toshiba, and BenQ

Durability Issues

Due to their portablility and tight integration, laptops are more subject to wear and physical damage than desktops. Components such as batteries, screen hinges, power jacks, and power cords are commonly subject to deterioration due to ordinary use. A liquid spill onto the keyboard, which is rather minor mishap with a desktop system can damage costly components such as the motherboard or LCD panel. Dropping a laptop can damage the LCD screen if not break apart its body. The repair costs of a failed motherboard or LCD panel may exceed the purchase value of the laptop.

Some manufacturers have mitigated some of these problems by selling "ruggedized" laptops. These often have a special drain in the keyboard that safely routes all of the water out through a hole in the bottom of the case. Additionally, the bodies of these laptops are typically made of magnesium alloy instead of plastic, and hard drives are often braced to greatly increase their chances of surviving a waist-high fall.

Advantages

The main advantage of laptops over their larger desktop counterparts is the inherent portability. Another advantage is the laptop's ability to operate on battery power in the case of a power outage and less energy consumption.

Upgradeability

Laptops' upgradeability is severely limited, both for technical and economic reasons. As of 2006, there is no industry-wide standard form factor for laptops. Each major laptop vendor pursues its own proprietary design and construction, with the result that laptops are difficult to upgrade and exhibit high repair costs. With few exceptions, laptop components can rarely be swapped between laptops of competing manufacturers, or even between laptops from the different product-lines of the same manufacturer. Standard feature peripherals (such as audio, video, USB, 1394, WiFi, Bluetooth) are generally integrated on the main PCB (motherboard), and thus upgrades often require using external ports, card slots, or wireless peripherals. Other components, such as RAM modules, hard drives, and batteries are typically user-upgradeable.

Many laptops have removable CPUs, although support for other CPUs is restricted to the specific models supported by the laptop motherboard. The socketed CPUs are perhaps for the manufacturer's convenience, rather than the end-user, as few manufacturers try new CPUs in last year's laptop model with an eye toward selling upgrades rather than new laptops. In many other laptops, the CPU is soldered and non-replaceable. [2]

Many laptops also include an internal MiniPCI slot, often occupied by a WiFi or Bluetooth card, but as with the CPU, the internal slot is often restricted in the range of cards that can be installed. The widespread adoption of USB mitigates I/O connectivity to a great degree, although the user must carry the USB peripheral as a separate item.

NVidia and ATI have proposed a standardized interface for laptop GPU upgrades (such as an MXM), but again, choices are limited compared to the desktop PCIe/AGP after-market.

In January 2007, Asus announced XG Station external video card for laptops. XG Station is connected to the laptops using USB-2 and Express card interface.

In February 2007, a new standard for external PCI Express cables and connectors was announced. Future laptops can be expanded using external PCI Express backplane and chassis.

Performance

A modern mid-range HP Laptop.

For a given price range (and manufacturing base), laptop computational power has traditionally trailed that of desktops. This is partly due to most laptops sharing RAM between the program memory and the graphics adapter. By virtue of their usage goals, laptops prioritize energy efficiency and compactness over absolute performance. Desktop computers and their modular components are built to fit much bigger standard enclosures, along with the expectation of AC line power. As such, energy efficiency and portability for desktops are secondary design goals compared to absolute performance.

For typical home (personal use) applications, where the computer spends the majority of its time sitting idle for the next user input, laptops of the thin-client type or larger are generally fast enough to achieve the required performance. 3D gaming, multimedia (video) encoding and playback, and analysis-packages (database, math, engineering, financial, etc.) are areas where desktops still offer the casual user a compelling advantage.

With the advent of dual-core processors and perpendicular recording, laptops are beginning to close the performance gap with desktops. Intel's Core 2 line of processors is efficient enough to be used in portable computers, and many manufacturers such as Apple, Lenovo and Dell are building Core 2 based laptops. Also, many high end laptop computers feature mobility versions of graphics cards, eliminating the performance losses associated with integrated graphics.

Health issues

Laptop coaster preventing heating of lap and improving laptop airflow.

A study by State University of New York researchers says heat generated from laptops can significantly elevate the temperature of the scrotum, potentially putting sperm count at risk. The small study, which included little more than two dozen men ages 13 to 35, found that the sitting position required to balance a laptop can raise scrotum temperature by as much as 2.1 °C (3.8 °F). Heat from the laptop itself can raise the temperature by another 0.7 °C (1.4 °F), bringing the potential total increase to 2.8 °C (5.2 °F). However, further research is needed to determine whether this directly affects sterility in men. [3] A common practical solution to this problem is to place the laptop on a table or desk.

Heat from using laptop on lap can also cause skin discoloration on the thighs. [4]

Because of their small keyboard and trackpad pointing devices, the use of laptops can cause RSI, and for this reason laptops have docks that are used with ergonomic keyboards to prevent injury. The integrated screen often causes users to hunch over for a better view, which can cause neck or spinal injuries. Some health standards require that ergonomic keyboards be used in workplaces.

Security

Laptops are generally prized targets of theft, and theft of laptops can lead to more serious problems such as identity theft from stolen credit card numbers.[5] Most laptops have a Kensington security slot to chain the computer to a desk with a third party security cable. In addition to this, modern operating systems and software may have disk encryption functionality that renders the data on the laptop's hard drive unreadable without a key.

A laptop can use the same software as a desktop machine but is small enough to support mobile computing and operate on battery power. Devices that are similar to a laptop include:

Transportable, also called portable computers
Computers which can easily be moved from place to place, but cannot be used while in transit, usually because they require AC power. The most famous example is the Osborne 1. A transportable, like a laptop, can run desktop software; but it does not support mobile computing.
Tablets
Computers shaped like slates or (paper) notebooks featuring touchscreen interfaces and a stylus, plus handwriting recognition software. As of 2007, the most common subcategory is the Tablet PC, which is essentially a laptop with a touchscreen. Some tablets have no keyboard, while others called "convertibles" have a screen that can be rotated 180 degrees and folded on top of the keyboard. Tablets may have limited functionality and not be best suited for applications requiring a physical keyboard for typing, but are otherwise capable of carrying out most tasks that an ordinary laptop would be able to perform.
Internet tablets
Internet appliances in tablet form. An internet tablet supports mobile computing. Internet tablets usually use Linux and they are able to run some applications, but they cannot replace a general purpose computer. Internet tablets typically feature an MP3 and video player, web browser, chat application, and picture viewer.
Personal digital assistants (PDAs)
Small computers, usually pocket-sized, usually with limited functionality. A PDA supports mobile computing, but almost never runs any desktop software.
Handheld computers
A high-end PDA or small tablet.
Smart phone
A hand held or PDA with an integrated cellphone.

Boundaries that separate these categories are blurry at times. For example, the OQO UPC is a PDA-sized tablet PC; the Apple eMate had the clamshell form factor of a laptop, but ran PDA software. The HP Omnibook line of laptops included some devices small enough to be called handheld computers. The hardware of the Nokia 770 internet tablet is essentially the same as that of a PDA such as the Zaurus 6000; the only reason it's not called a PDA is that it doesn't have PIM software. On the other hand, both the 770 and the Zaurus can run some desktop Linux software, usually with modifications.

Major brands and manufacturers

summary="Links to Wikipedia articles about laptop manufacturers. For some of them, articles about the company's most well-known models or series are linked as well."

See also

Wikimedia Commons has media related to Laptop.

References

  1. ^ "Notebook OEM/ODM relationships". Retrieved 2007-06-28.
  2. ^ Thus, there is no practical way to update it on models which already feature the latest processor for their motherboard.
  3. ^ Sheynkin, Y. (2004-12-9). "Increase in scrotal temperature in laptop computer users". Human Reproduction. 20 (2). Epub: 452–5. Retrieved 2006-12-14. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  4. ^ Levinbook, WS. (2007 Oct). "Laptop computer--associated erythema ab igne". Cutis. 80 (4). Quadrant HealthCom: 319–20. Retrieved 2008-2-19. {{cite journal}}: Check date values in: |accessdate= and |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  5. ^ TuxMobil's page with a list of information and protection devices
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