A laptop is a portable personal computer with a clamshell form factor, suitable for mobile use.[1] A laptop has most of the same components as a desktop computer, including a display, a keyboard, a pointing device such as a touchpad (also known as a trackpad) and/or a pointing stick, and speakers into a single unit. A laptop is powered by mains electricity via an AC adapter, and can be used away from an outlet using a rechargeable battery. Laptops are also sometimes called notebook computers or notebooks. Other terms, such as ultrabooks or netbooks, refer to specific typesof laptop / notebook. Most of the modern day laptop computers also have a webcam and a mic (microphone) pre-installed.
Portable computers, originally monochrome CRT-based and developed into the modern laptops, were originally considered to be a small niche market, mostly for specialized field applications such as the military, accountants and sales representatives. As portable computers became smaller, lighter, cheaper, and more powerful and as screens became larger and of better quality, laptops became very widely used for a variety of purposes.
History
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As the personal computer (PC) became feasible in the 1970s, the idea of a portable personal computer followed. A "personal, portable information manipulator" was imagined by Alan Kay at Xerox PARC in 1968,[2] and described in his 1972 paper as the "Dynabook".[3]
The IBM Special Computer APL Machine Portable (SCAMP), was demonstrated in 1973. This prototype was based on the IBM PALM processor (Put All Logic in Microcode or 128 bit).
The IBM 5100, the first commercially available portable computer, appeared in September 1975, and was based on the SCAMP prototype.[4]
As 8-bit CPU machines became widely accepted, the number of portables increased rapidly. The Osborne 1, released in 1981, used the Zilog Z80 and weighed 23.6 pounds (10.7 kg). It had no battery, a 5 in (13 cm) CRT screen, and dual 5.25 in (13.3 cm) single-density floppy drives. In the same year the first laptop-sized portable computer, the Epson HX-20, was announced.[5] The Epson had a LCD screen, a rechargeable battery, and a calculator-size printer in a 1.6 kg (3.5 lb) chassis. Both Tandy/RadioShack and HP also produced portable computers of varying designs during this period.[6][7]
The first laptops using the flip form factor appeared in the early 1980s. The Dulmont Magnum was released in Australia in 1981–82, but was not marketed internationally until 1984–85. The US$8,150 (US$19,390 today) GRiD Compass 1100, released in 1982, was used at NASA and by the military among others. The Gavilan SC, released in 1983, was the first computer described as a "laptop" by its manufacturer.[8] From 1983 onward, several new input techniques were developed and included in laptops, including the touchpad (Gavilan SC, 1983), the pointing stick (IBM ThinkPad 700, 1992) and handwriting recognition (Linus Write-Top,[9] 1987). Some CPUs, such as the 1990 Intel i386SL, were designed to use minimum power to increase battery life of portable computers, and were supported by dynamic power management features such as Intel SpeedStep and AMD PowerNow!in some designs.
Displays reached VGA resolution by 1988 (Compaq SLT/286), and colour screens started becoming a common upgrade in 1991 with increases in resolution and screen size occurring frequently until the introduction of 17"-screen laptops in 2003. Hard drives started to be used in portables, encouraged by the introduction of 3.5" drives in the late 1980s, and became common in laptops starting with the introduction of 2.5" and smaller drives around 1990; capacities have typically lagged behind physically larger desktop drives. Optical storage, read-only CD-ROM followed by writeable CD and later read-only or writeable DVD and Blu-ray, became common in laptops early in the 2000s
Classification[edit]
- Full-size Laptop: A laptop large enough to accommodate a "full-size" keyboard (a keyboard with the minimum QWERTY key layout, which is at least 13.5 keys across that are on ¾ (0.750) inch centers, plus some room on both ends for the case). The measurement of at least 11 inches across has been suggested as the threshold for this class.[12] The first laptops were the size of a standard U.S. "A size" notebook sheet of paper (8.5 × 11 inches)[citation needed], but later "A4-size" laptops were introduced, which were the width of a standard ISO 216 A4 sheet of paper (297 mm, or about 11.7 inches), and added a vertical column of keys to the right and wider screens. It can also be laid sideways when not in use.
- Netbook: A smaller, lighter, and therefore more portable laptop with less computing power than traditional laptops. It is usually cheaper than a full-size laptop, and has fewer features. The smaller keyboards of a netbook can be more difficult to operate. There is no definitive demarcation between netbooks and inexpensive small laptops, some 11.6" models are marketed as netbooks. Since netbook laptops are quite small in size and designed to be light and inexpensive they typically do not come with an internal optical drive. The Asus Eee PC launched this product class, while the term was coined later by Intel. Most netbooks feature cheaper, slower, but more energy efficient CPUs, as compared to traditional laptops, such as the Intel Atom CPU.
- Tablet PC: These have touch screens. There are "convertible tablets" with a full keyboard where the screen rotates to be used atop the keyboard, a "hybrid tablet" where the keyboard can be detached from the screen, and "slate" form-factor machines which are usually touch-screen only (although a few older models feature very small keyboards along the sides of the screen.)
- Ultra-mobile PC: An ultra-mobile PC (ultra-mobile personal computer or UMPC) is a small form factor version of a pen computer, a class of laptop whose specifications were launched by Microsoft and Intel in spring 2006. Sony had already made a first attempt in this direction in 2004 with its Vaio U series, which was only sold in Asia. UMPCs are smaller than subnotebooks, have a TFT display measuring (diagonally) about 12.7 to 17.8 cm, and are operated like tablet PCs using a touchscreen or a stylus. This term is commonly (if inaccurately) used for small notebooks and/or netbooks.
- Handheld PC: A Handheld PC, or H/PC for short, is a term for a computer built around a form factor which is smaller than any standard laptop computer. It is sometimes referred to as a Palmtop. The first handheld device compatible with desktop IBM personal computers of the time was the Atari Portfolio of 1989. Other early models were the Poqet PC of 1989 and the Hewlett Packard HP 95LX of 1991. Other DOS compatible hand-held computers also existed.
- Rugged: Engineered to operate in tough conditions (mechanical shocks, extreme temperatures, wet and dusty environments, etc.)
- Ultrabook: A very thin version of a laptop by definition less than 0.8 inches thick. Most versions of Ultrabooks contain SSD, or Solid-State Drives, instead of the common Laptop Hard Disk Drives. Although this term (like Netbook) was coined and popularized by Intel, one of the most prominent examples is Apple's Macbook Air.
Desktop replacement[edit]
Main article: Desktop replacement computer
A desktop-replacement computer is a laptop that provides all of the capabilities of a desktop computer, with a similar level of performance. Desktop replacements are usually larger and heavier than standard laptops. They contain more powerful components and have a 15" or larger display.[11] They are bulkier and not as portable as other laptops, and their operation time on batteries is typically shorter; they are intended to be used as compact and transportable alternatives to a desktop computer.[11]
Some laptops in this class use a limited range of desktop components to provide better performance for the same price at the expense of battery life; a few of those models have no battery.[13] In the early 2000s, desktops were more powerful, easier to upgrade, and much cheaper than laptops, but in later years laptops have become much cheaper and more powerful than before,[14] and most peripherals are available in laptop-compatible USB versions which minimize the need for internal add-on cards.
The names "Media Center Laptops" and "Gaming Laptops" are used to describe specialized notebook computers.[10]
Subnotebook[edit]
Main article: Subnotebook
A subnotebook or ultraportable is a laptop designed and marketed with an emphasis on portability (small size, low weight and often longer battery life) that retains performance close to that of a standard notebook. Subnotebooks are usually smaller and lighter than standard laptops, weighing between 0.8 and 2 kg (2 to 5 pounds);[10] the battery life can exceed 10 hours[15] when a large battery or an additional battery pack is installed. Since the introduction of netbooks, the line between subnotebooks and higher-end netbooks has been substantially blurred.
To achieve the size and weight reductions, ultraportables use 13" and smaller screens (down to 6.4"), have relatively few ports (but in any case include two or more USB ports), employ expensive components designed for minimal size and best power efficiency, and utilize advanced materials and construction methods. Most subnotebooks achieve a further portability improvement by omitting an optical/removable media drive; in this case they may be paired with a docking station that contains the drive and optionally more ports or an additional battery.
The term "subnotebook" is reserved to laptops that run general-purpose desktop operating systems such as Windows, Linux or Mac OS X, rather than specialized software such as Windows CE,iOS, Palm OS or Internet Tablet OS.
At Computex 2011 Intel announced a new class for ultraportables called Ultrabooks. The term is used to describe a highly portable laptop that has strict limits for size, weight, battery life, and have tablet-like features such as instant on functionality. Intel estimates that by the end of 2012, 40 percent of the consumer laptop market segment will be Ultrabooks.[16]
Netbook[edit]
Main article: Netbook
Netbooks are laptops that are inexpensive, light-weight, economical, energy-efficient and especially suited for wireless communication and Internet access.[17][18] Hence the name netbook (as "the device excels in web-based computing performance").[19]
With primary focus given to web browsing and e-mailing, netbooks are intended to "rely heavily on the Internet for remote access to web-based applications"[19] and are targeted increasingly at cloud computing users who rely on servers and require a less powerful client computer.[20] A common distinguishing feature is the lack of optical disk (i.e. CD, DVD or Blu-ray) drives. While the devices range in size from below 5 inches to over 12 inches,[21] most are between 9 and 11 inches (280 mm) and weigh between 0.9–1.4 kg (2–3 pounds).[19]
Netbooks are mostly sold with light-weight operating systems such as Linux, Windows XP and Windows 7 Starter edition.
Netbooks do have a few disadvantages. Because the netbooks are so thin, the first products introduced to the market utilized solid-state drives for internal storage instead of traditional hard disks, increasing cost and lowering storage space. Hard disk drive technology and form factors have since been adapted to fit into netbooks providing more hard drive space without increasing cost, a key point of a netbook. Another issue with netbooks is expansion. In order to produce small, inexpensive laptops, netbooks generally lack significant upgrade ability. A majority of netbooks only have a single memory slot and will not recognize any amount beyond 2 GB of RAM. This limits the capabilities of the netbook beyond basic functionality (internet, e-mail, etc.). Finally because of their size and use of more rudimentary components compared to notebooks and subnotebooks, netbooks also generally have a slower CPU[22]
In 2009, Google announced an operating system called Google Chrome OS for this market and in 2011 the Google Chromebook was released running on the Google Chrome OS.
The big breakthrough for netbook computers did not happen until the weight, diagonal form-factor and price combination of < 1 kg, < 9", < U.S. $400, respectively, became commercially available in around 2008.
Rugged laptop[edit]
Main article: Rugged computer
A rugged/ruggedized laptop is designed to reliably operate in harsh usage conditions such as strong vibrations, extreme temperatures, and wet or dusty environments. Rugged laptops are usually designed from scratch, rather than adapted from regular consumer laptop models. Rugged laptops are bulkier, heavier, and much more expensive than regular laptops,[23] and thus are seldom seen in regular consumer use.
The design features found in rugged laptops include rubber sheeting under the keyboard keys, sealed port and connector covers, passive cooling, superbright displays easily readable in daylight, cases and frames made of magnesium alloys that are much stronger than plastic found in commercial laptops, and solid-state storage devices or hard disc drives that are shock mounted to withstand constant vibrations. Rugged laptops are commonly used by public safety services (police, fire and medical emergency), military, utilities, field service technicians, construction, mining and oil drilling personnel. Rugged laptops are usually sold to organizations, rather than individuals, and are rarely marketed via retail channels.
Tablet laptop[edit]
See also: Tablet computer
Typical modern convertible laptops have a complex joint between the keyboard housing and the display permitting the display panel to swivel and then lie flat on the keyboard housing. Tablet laptops also contain touchscreen displays alongside the traditional touchpad.
Typically, the base of a tablet laptop attaches to the display at a single joint called a swivel hinge or rotating hinge. The joint allows the screen to rotate through 180° and fold down on top of the keyboard to provide a flat writing surface. This design, although the most common, creates a physical point of weakness on the laptop.
Some manufacturers have attempted to overcome these weak points by adopting innovative methods such as a sliding design in which the screen slides up from the slate-like position and locks into place to provide the laptop mode. Newer iterations of tablet laptops are of hybrid design. Hybrid tablets incorporate a removable keyboard base allowing the user to easily choose between functioning as a laptop with the keyboard attached or as a slate device utilizing the touchscreen alone.
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