computers are used in many places in which most of them use laptops.A laptop computer, or simply laptop (also notebook computer, notebook and notepad) is a small mobile computer, which usually weighs 2-18 pounds (around 1 to 8 kilograms), depending on size, materials, and other factors.Laptops usually run on a single main battery or from an external AC/DC adapter which can charge 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.As personal computers, laptops are capable of the same tasks as a desktop computer, although they are typically less powerful for the same price. They contain components that are similar to their desktop counterparts and perform the same functions, but are miniaturizedand optimized for mobile use and efficient power consumption. Laptops usually have liquid crystal displays and most of them use different memory modules for their random access memory (RAM), for instance, SO-DIMMin 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.CategoriesThin-and-lightsLaptops usually weighing in between 4 and 6 lb (1.8–2.7 kg) with a screen size of between 12 and 14 inches (30–35 cm) diagonally.MainstreamLaptops weighing in between 5 and 7 lb (2.3–3.2 kg), with a screen size of 14.1 inches and 15.4 inches (35 and 39 cm).Desktop replacement computersPowerful 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.can be understood as a particular point on the continuum of more or less portable computing devices: the point at which the device is large enough to use substantially the same software as a desktop machine, but small enough to support mobile computig. Other points on the continuum include:Transportable, also called portable computersComputers 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.TabletsComputers shaped like slates or (paper) notebooks, with touchscreen interfaces include a magnetized stylus and software for allowing input to be recognized by the touch screen. As of 2007, the most common subcategory is the Tablet PC, which is essentially a laptop with a touchscreen. Some tablets have no keyboard; others, called "convertibles", have a screen which can be rotated 180 degrees and folded on top of the keyboard. Tablets may have limited functionality in certain applications that require an actual physical keyboard for typing, but are otherwise capable of carrying out most tasks that an ordinary laptop would be able to perform.Internet tabletsInternet 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 cant replace a computer. Internet tablets feature MP3, video, internet browser, chat, 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 computersA high-end PDA or small tablet.Smart phoneA 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 Zaurus6000; 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.An opened Osborne 1 computer, ready for use. The keyboard sits on the inside of the lid.HistoryBefore laptop/notebook computers were technically feasible, similar ideas had been proposed, most notably Alan Kay's Dynabook concept, developed at Xerox PARC in the early 1970s.The first commercially available portable computer was the Osborne 1 in 1981, which used the CP/M operating system. Although it was large and heavy compared to today's laptops, with a tiny CRT monitor, it had a near-revolutionary impact on business, as professionals were able to take their computer and data with them for the first time. This and other "luggables" were inspired by what was probably the first portable computer, the Xerox NoteTaker again developed at Xerox PARC, in 1976; however, only ten prototypes were built. The Osborne was about the size of a portable sewing machine, and importantly could be carried on a commercial aircraft. However, it was not possible to run the Osborne on batteries: it had to be plugged into mains.In 1982 Kaypro introduced the Kaypro II, a CP/M-based competitor to the Osborne 1. The Kaypro II featured a display nearly twice as big as the Osborne's and double-sided floppy drives with twice the storage capacity.A more enduring success was the Compaq Portable, the first product from Compaq, introduced in 1983, by which time the IBM Personal Compur had become the standard platform. Although scarcely more portable than the Osborne machines, and also requiring AC power to run, it ran MS-DOS and was the first true IBM clone(IBM's own later Portable Computer, which arrived in 1984, was notably less IBM PC-compatible than the CompaqAnother significant machine announced in 1981, although first sold widely in 1983, was the Epson HX-20. A simple handheld computer, it featured a full-transit 68-key keyboard, rechargeable nickel-cadmium batteries, a small (120 x 32-pixel) dot-matrix LCD display with 4 lines of text, 20 characters per line text mode, a 24 column dot matrix printer a Microsoft BASICinterpreter, and 16 KB of RAM (expandable to 32 KB).However, arguably the first true laptop was the GRiD Compass 1101, designed by Bill Moggridge in 1979-1980, and released in 1982. Enclosed in a magnesium case, it introduced the now familiar clamshell design, in which the flat display folded shut against the keyboard. The computer could be run from batteries, and was equipped with a 320×200-pixel plasma display and 384 kibibytebubble memory. It was not IBM-compatible, and its high price (US$8,000–10,000) limited it to specialized applications.
However, it was used heavily by the U.S. military, and by NASA on the Space Shuttle during the 1980s. The GRiD's manufacturer subsequently earned significant returns on its patent rights as its innovations became commonplace. GRiD Systems Corp. was later bought by the Tandy (now RadioShack) Corporation.The Ampere[1] a sleek clamshell design by Ryu Oosake also debuted in 1983. It offered aTwo other noteworthy early laptops were the Sharp PC-5000 and the Gavilan SC, announced in 1983 but first sold in 1984. The Gavilan was notably the first computer to be marketed as a "laptop". It was also equipped with a pioneering touchpad-like pointing device, installed on a panel above the keyboard. Like the GRiD Compass, the Gavilan and the Sharp were housed in clamshell cases, but they were partly IBM-compatible, although primarily running their own system software. Both had LCD displays, and could connect to optional external printers. The Dulmont Magnum, launched internationally in 1984, was an Australian portable similar in layout to the Gavilan, which used the Intel 80186 processorThe year 1983 also saw the launch of what was probably the biggest-selling early laptop, the KyoceraKyotronic 85. Owing much to the design of the previous Epson HX-20, and although at first a slow seller in Japan, it was quickly licensed by Tandy Corporation, Olivetti, and NEC who recognised its potential and marketed it respectively as the TRS-80 Model 100 line (or Tandy 100), Olivetti M-10, and NEC PC-8201[The machines ran on standard AA batteries. The Tandy's built-in programs, including a BASIC interpreter, a text editor, and a terminal program, were supplied by Microsoft, and are thought to have been written in part by Bill Gates himself. The computer was not a clamshell, but provided a tiltable 8×40-character LCD screen above a full-travel keyboard. With its internal modem, it was a highly portable communications terminal. Due to its portability, good battery life (and ease of replacement), reliability (it had no moving parts), and low price (as little as US$300), the model was highly regarded, becoming a favorite among journalists. It weighed less than 2 kg with dimensions of 30×21.5×4.5 centimeters (12×8½×1¾ in). Initial specifications included 8 kilobytes of RAM (expandable to 24 KB) and a 3 MHz processor. The machine was in fact about the size of a paper notebook, but the term had yet to come into use and it was generally described as a "portable" computer.Possibly the first commercial IBM-compatible laptop was the Kaypro 2000, introduced in 1985. With its brushed aluminum clamshell case, it was remarkably similar in design to modern laptops.
It featured a 25 line by 80 character LCD display, a detachable keyboard, and a pop-up 90 mm (3.5 inch) floppy drive.Also among the first commercial IBM-compatible laptops were the IBM PC Convertible, introduced in 1986, and two Toshibamodels, the T1000 and T1200, introduced in 1987. Although limited floppy-based DOS machines, with the operating system stored in read-on memory, the Toshiba models were small and light enough to be carried in a backpack, and could be run off lead-acid batteries.
These also introduced the now-standard "resume" feature to DOS-based machines: the computer could be paused between sessions, without having to be restarted each time.The first laptops successful on a large scale came in large part due to a Request For Proposal (RFP) by the U.S. Air Force in 1987. This contract would eventually lead to the purchase of over 200,000 laptops. Competition to supply this contract was fiercely contested and the major PC companies of the time; IBM, Toshiba, Compaq, NEC, and Zenith Data Systems (ZDS), rushed to develop laptops in an attempt to win this deal. ZDS, which had earlier won a landmark deal with the IRS for its Z-171, was awarded this contract for its SupersPort series. The SupersPort series was originally launched with an Intel 8086 processor, dual floppy disk drives, a backlit, blue and white STN LCD screen, and a NiCD battery pack. Later models featured an Intel 80286 processor and a 20 MB hard disk drive. On the strength of this deal, ZDS became the world's largest laptop supplier in 1987 and 1988. ZDS partnered with Tottori Sanyo in the design and manufacturing of these laptops. This relationship is notable because it was the first deal between a major brand and an Asian original equipment manufacturer.Another notable computer was the Cambridge Z88, designed by Clive Sinclair, introduced in 1988.
About the size of an A4 sheet of paper as well, it ran on standard batteries, and contained basic spreadsheet word processing, and communications programs. It anticipated the future miniaturization of the portable computer, and as a ROM-based machine with a small display, can—like the TRS-80 Model 100—also be seen as a forerunner of the personal digital assistant.By the end of the 1980s, laptop computers were becoming popular among business people. The NEC UltraLite, released in mid-1989, was perhaps the first notebook computer, weighing just over 2 kg; in lieu of a floppy or hard drive, it contained a 2 mebibyte RAM drive, but this reduced its utility as well as its size. The first notebook computers to include hard drives were those of the Compaq LTEseries, introduced toward the end of that year. Truly the size of a notebook, they also featured grayscale backlit displays with CGA resolution.
The Macintosh Portable, Apple's first attempt at a battery-powered computerThe first Apple Computer machine designed to be used on the go was the 1989 MacintPortable (although an LCD screen had been an option for the transportable Apple IIc in 1984). Unlike the Compaq LTE Laptop Released earlier in the year the Macintosh Portable was Actually a "luggable" not a laptop, but the Mac Portable was praised for its clear active matrixdisplayand long battery life, but was a poor seller due to its bulk. In the absence of a true Apple laptop, several compatible machines such as the Outbound Laptop were available for Mac users; however, for copyright reasons, the user had to supply a set of Mac ROMs, which usually meant having to buy a new or used Macintosh as well.The Apple PowerBook series, introduced in October 1991, pioneered changes that are now de facto standards on laptops, such as room for a palm rest, and the inclusion of a (a trackball). The following year, IBM released its ThinkPad 700C, featuring a similar design (though with a distinctive red TrackPoint pointing device).Later PowerBooks introduced the first 256-color displays (PowerBook 16c, 1993), and first true touchpad, first 16-bit sound recording, and first built-in Ethernet network adapter (PowerBook 500, 1994).In 1994, IBMreleased RS/6000 N40 PowerPC laptop running AIX (Operating system based on UNIX), manufactured by Tadpole.
Tadpole also manufactured laptops based on SPARC and DEC Alpha CPUs.The summer of 1995 was a significant turning point in the history of notebook computing. In August of that year Microsoft introduced Windows 95. It was the first time that Microsoft had placed much of the power management control in the operating system. Prior to this point each brand used custom BIOS, drivers and in some cases, ASICs, to optimize the battery life of its machines. This move by Microsoft was controversial in the eyes of notebook designers because it greatly reduced their ability to innovate; however, it did serve its role in simplifying and stabilizing certain aspects of notebook design. Windows 95 also ushered in the importance of the CD-ROM drive in mobile computing, and initiated the shift to the Intel Pentium processor as the base platform for notebooks.
The Gateway Solo was the first notebook introduced with a Pentium processor and a CD-ROM. Also featuring a removable hard disk drive and floppy drive, the Solo was the first three-spindle (optical, floppy, and hard disk drive) notebook computer, and was extremely successful within the consumer segment of the market. In roughly the same time period the Dell Latitude Toshiba Satellite, and IBM ThinkPad were reaching great success with Pentium-based two-spindle (hard disk and floppy disk drive) systems directed toward the corporate market.
