标题：laptop
简介
A laptop computer or simply laptop (also notebook computer or notebook) is a small mobile personal computer,usually weighing from two to six pounds (one to three kilograms),depending on size,materials and other factors.
While the terms "laptop" and "notebook" are often used interchangeably,"laptop" is the older term,introduced in 1983 with the Gavilan SC. "Notebook computer" is a later coinage,which was used to differentiate smaller devices such as those of the NEC UltraLite and Compaq LTE series in 1989,which were,in contrast to previous laptops,the approximate size of an A4 paper sheet.[1] Either term is often used improperly: due to heat and other issues,many laptops are inappropriate for use on one's lap,and most are not the size of an A4 sheet. Although,some older portable computers,such as the Macintosh Portable and certain Zenith TurbosPort models,were sometimes described as "laptops",their size and weight were too great for this category.
相关资料
产生背景Laptops usually run on a single battery or from an external AC/DC adapter which can charge the battery while also supplying power to the computer itself.
As personal computers,laptops are capable of the same tasks as a desktop PC,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 miniaturized and optimized for mobile use and efficient power consumption. Laptops usually have liquid crystal displays and most of them use different memory modules for their 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.
使用类型Terms sometimes used for subtypes of laptop computers include:
Ultraportables 
Laptops with screens typically less than 12 inches diagonally and a weight of less than 1.7kg. Their keyboards are usually not full-size. Their primary audience is usually business travelers,who need small,light laptops. Ultraportables are often very expensive and house power-saving CPUs and almost always have integrated graphics. 
Thin-and-lights 
Laptops usually weighing in between 1.8kg and 2.8kg with a screen size of between 12 and 14 inches diagonally. 
Medium-sized laptops 
These usually have screens of 15 - 15.4 inches diagonally and a weight of around 3-3.5kg. They usually sacrifice a little computing power for smaller dimensions and longer battery life,although the length and width are usually determined by the screen size. 
Desktop replacement computers 
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 15 inches or more. Desktop replacements tend to have limited battery life,rarely exceeding three hours,because the hardware is not optimized for efficient power usage.
发展历史History
Before 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 in.
A more enduring success was the Compaq Portable,the first product from Compaq,introduced in 1983,by which time the IBM Personal Computer 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 Compaq[citation needed]).
Another 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 BASIC interpreter,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 kilobyte bubble memory. It was not IBM-compatible,and its high price (US$ 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 Tandy (RadioShack).
Two 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 year 1983 also saw the launch of what was probably the biggest-selling early laptop,the Kyocera Kyotronic 85,which owed much to the design of the previous Epson HX-20. Although it was at first a slow seller in Japan,it was quickly licensed by Tandy Corporation,Olivetti,and NEC,which saw its potential and marketed it respectively as TRS-80 Model 100 line (or Tandy 100），Olivetti M-10,NEC PC-8201.[2] 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 cm （12 × 8.5 × 1.75 inches). Initial specifications included 8 kilobyte 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.
Among the first commercial IBM-compatible laptops were the IBM PC Convertible,introduced in 1986,and two Toshiba models,the T1000 and T1200,introduced in 1987. Although limited floppy-based DOS machines,with the operating system stored in read-only 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 20MB 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 OEM (Original Equipment Manufacturer). At the time,Compaq,IBM,Toshiba,NEC,etc. all designed and manufactured their own machines. However,after the success of the ZDS offering other relationships,like Compaq and Citizen,soon followed. At this time the quality of Japanese engineering and manufacturing in conjunction with the strength of the dollar relative to the yen (typically about 130 Yen = $1） drove most brands to suppliers in Japan. Companies such as Sanyo,Tottori Sanyo,Citizen,and Casio were all heavily involved in this business as OEMs. However,by the mid-1990s a weakening dollar and the rising viability of Taiwanese OEMs such as Acer,Quanta,Compal,Twinhead,and Chicony lead the supply base to rapidly shift from Japan to Taiwan. Additionally,brands which were more nimble and relied less on internal engineering such as Gateway,Dell and Micron began to rise quickly to leadership positions. Combinations such as Dell/Compal and Gateway/Quanta eventually became powerhouse partnerships and greatly contributed to the prominence of Taiwanese OEMs as the center of PC manufacturing from about 1995 onward.
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 megabyte 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 LTE series,introduced toward the end of that year. Truly the size of a notebook,they also featured backlit displays with CGA resolutions (though not CGA colors).
The first Apple Computer machine designed to be used on the go was the 1989 Macintosh Portable (although an LCD screen had been an option for the transportable Apple Ⅱc in 1984）. Actually a "luggable",the Mac Portable was praised for its clear active matrix display and 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 the placement of the keyboard,room for palm rest,and the inclusion of a built-in pointing device (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 165c,1993），and first true touchpad,first 16-bit sound recording,and first built-in Ethernet network adapter (PowerBook 500,1994）.
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 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. By also featuring a removable hard disk drive and floppy drive it was the first three-spindle (optical,floppy,and hard disk drive) notebook computer. The Gateway Solo 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.
An old （1997） Micron laptopAs technology improved during the 1990s,the usefulness and popularity of laptops increased. 
Correspondingly prices went down. Several developments specific to laptops were quickly implemented,improving usability and performance. Among them were:
Improved battery technology. The heavy lead-acid batteries were replaced with lighter and more efficient technologies,first nickel cadmium or NiCD,then nickel metal hydride (NiMH) and then lithium ion battery and lithium polymer. 
Power-saving processors. While laptops in 1991 were limited to the 80286 processor because of the energy demands of the more powerful 80386,the introduction of the Intel 386SL processor,designed for the specific power needs of laptops,marked the point at which laptop needs were included in CPU design. The 386SL integrated a 386SX core with a memory controller and this was paired with an I/O chip to create the SL chipset. It was more integrated than any previous solution although its cost was higher. It was heavily adopted by the major notebook brands of the time. Intel followed this with the 486SL chipset which used the same architecture. However,Intel had to abandon this design approach as it introduced its Pentium series. Early versions of the mobile Pentium required TAB mounting (also used in LCD manufacturing) and this initially limited the number of companies capable of supplying notebooks. However,Intel did eventually migrate to more standard chip packaging. One limitation of notebooks has always been the difficulty in upgrading the processor which is a common attribute of desktops. Intel did try to solve this problem with the introduction of the MMC for mobile computing. The MMC was a standard module upon which the CPU and external cache memory could sit. It gave the notebook buyer the potential to upgrade his CPU at a later date,eased the manufacturing process some,and was also used in some cases to skirt U.S. import duties as the CPU could be added to the chassis after it arrived in the U.S. Intel stuck with MMC for a few generations but ultimately could not maintain the appropriate speed and data integrity to the memory subsystem through the MMC connector. 
Improved liquid crystal displays,in particular active-matrix TFT (Thin-Film Transistor) LCD technology. Early laptop screens were black and white,blue and white,or grayscale,STN (Super Twist Nematic) passive-matrix LCDs prone to heavy shadows,ghosting and blurry movement (some portable computer screens were sharper monochrome plasma displays,but these drew too much current to be powered by batteries). Color STN screens were used for some time although their viewing quality was poor. By about 1991,two new color LCD technologies hit the mainstream market in a big way; Dual STN and TFT. The Dual STN screens solved many of the viewing problems of STN at a very affordable price and the TFT screens offered excellent viewing quality although initially at a steep price. DSTN continued to offer a significant cost advantage over TFT until the mid-90s before the cost delta dropped to the point that DSTN was no longer used in notebooks. Improvements in production technology meant displays became larger,sharper,had higher native resolutions,faster response time and could display color with great accuracy,making them an acceptable substitute for a traditional CRT monitor. 
Improved hard disk technology. Early laptops and portables had only floppy disk drives. As thin,high-capacity hard disk drives with higher reliability and shock resistance and lower power consumption became available,users could store their work on laptop computers and take it with them. The 3.5" HDD was created initially as a response to the needs of notebook designers that needed smaller,lower power consumption products. As pressure to continue to shrink the notebook size even further,the 2.5" HDD was introduced. 
Improved connectivity. Internal modems and standard serial,parallel,and PS/2 ports on IBM PC-compatible laptops made it easier to work away from home; the addition of network adapters and,from 1997,USB,as well as,from 1999,Wi-Fi,made laptops as easy to use with peripherals as a desktop computer. 
Parts
Most modern laptops feature 12 inch （304.8 mm) or larger active matrix displays with resolutions of 1024×768-pixels and above,and have a PC-Card expansion bay for expansion cards (formerly PCMCIA). Internal hard disks are physically smaller –2.5 inch （63.5 mm）– compared to the standard desktop 3.5 inch （88.9 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. 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. 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 –with Centrino technology–，Celeron,Intel Core Duo and Centrino Duo) and from AMD (Athlon,Turion 64,and Sempron). 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 have been 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:
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. 
Docking stations became common laptop accessories in the early 90's. 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 were 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. 
[edit] Laptop Spare Categories
While there are accepted world standard of form factors for all the peripherals and add-in PC cards used in the desktop computers,there are still no world standard form factors for all the laptop computer used today,such as supply of electric voltage,layout of mother board,adapter used in connecting the hard disk,optical drive,LCD cable,keyboard and floppy drive to the main board. Every manufacturer created and used their own design in manufacturing the proprietary parts for their own brand of laptop. Parts used in laptop produced by a laptop manufacture could not be used in others. Consumers ultimately pay for the additional cost that could have been saved if having the standard form factor for the laptop parts.
The name of the parts or the name of category used also differs from manufacturer to manufacturer,such system board used by IBM and motherboard used by Compaq,display cable,LCD cable,flexi-cable are the terms used by the general public refer to the cable connecting the LCD screen to the main board for transferring the digital signal. The cover around the keyboard where the palm is rested called palm rest by Dell,keyboard bezel by IBM,upper cpu cover by Compaq and top case sub assembly by Asus.
Summary all the differences there are 7 main categories consisting of 100 sub categories for all the spare part used in all laptop computers as organized by pchub,there are also 8 categories for parts,such as hard disk and optical drive manufactured by the OEM (Original Equipment Manufacturer),which are the common parts that generally used in all the laptop.
Main categories for all the laptop spare parts.
Laptop Spare Part: &raquo;Adaptor / Battery &raquo;Fan / Hinge / CPU &raquo;LCD Related &raquo;Main/Key/ Board Related &raquo;Drive Related &raquo;Cover / Casing Related &raquo;Docking / Replicater
OEM Spare Part: &raquo;AC Adapter &raquo;DC Car Adapter &raquo;LCD &raquo;Fluorescent Tube &raquo;Optical Drive &raquo;Various jack &raquo;Floppy &raquo;Hard Disk 2.5"
[edit] 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,[3]
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.
Performance
For a given price range (and manufacturing base),laptop computational power has traditionally trailed that of desktops. 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 larger standard enclosures,along with the expectation of (AC) wall-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.
But with the advent of dual-core processors and perpendicular recording hard disks,laptops could soon rival desktops in speed and performance.
[edit] Health issues
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 study,which included more than two dozen men ages 21 to 35,found that the sitting position required to balance a laptop can raise scrotum temperature by as much as 2.1 degrees Celsius. Heat from the laptop itself can raise the temperature by another 0.7 C,bringing the potential total increase to 2.8 C.
[edit] 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.[4]
[edit] Manufacturers
Acer - TravelMate and Aspire 
Advent 
Alienware - Area 51m,Alienware Sentia and Aurora m series 
Apple Computer - MacBook and MacBook Pro 
ASUS 
Averatec 
BenQ 
Clevo 
Compaq - EVO,Armada,LTE,and Presario 
CyberPower PCs 
Dell - Inspiron,Latitude and Precision 
ECS 
Falcon Northwest - DR6800,TL2 
Fujitsu Siemens - Lifebook,FMV - BiBlo,Amilo 
Gateway 
Gericom 
HCL 
Hewlett-Packard - HP Pavilion and HP Omnibook 
Hypersonic 
Lenovo 
LG - XNOTE 
LinuxCertified - Linux laptop 
Medion 
NEC - VERSA,LaVie 
Packard Bell - EasyNote 
Panasonic - Toughbook,Let's Note (available in Japan only) 
Samsung - Sens 
Sharp - Mebius 
Sony - VAIO 
Toshiba - Dynabook,Equium,Portege,Tecra,Satellite,Qosmio,Libretto 
Voodoo PC - Envy 
[edit] See also
Desktop computer 
Portable computer 
Desktop replacement computer 
Palmtop 
Personal computer 
PDA 
Tablet PC 
Subnotebook 
List of computer size categories 
[edit] Notes
1^ As far as this distinction is concerned,the "thickness" ("vertical height") of the machine is disregarded; only its width and depth are considered 
2^ See TRS-80 Model 100 / 102 at 　3^ thus there is no practical way to update it on models which already feature the latest processor for their motherboard. 
4^ TuxMobil's page with a list of information and protection devices
中文翻译
产生背景一个笔记型电脑或只是膝上型电脑 （也笔记型计算机或笔记型） 是一个小的移动个人计算机，通常来自二到六个镑 （一至三公斤） 的秤重，仰赖规模、材料和其他的因数。
当条件 " 膝上型电脑 " 和 " 笔记型 " 时常可互相交换地被使用的时候， " 膝上型电脑 " 是较旧的期，在 1983 年以 Gavilan SC 引进了。" 笔记型计算机 " 是一个较迟的造币，被使用在 1989 年区别 NEC UltraLite 和 Compaq LTE 级数的像如此的较小的装置，这是，与以前的膝上型电脑，A 4 证券纸张的近似规模相反。[1] 任一期时常不适当地被使用： 满期加热和其他的发行，许多膝上型电脑在一个余面上对使用是不适当的，而且大部分不是 A 4 纸张的规模。虽然，像麦金塔轻便的和特定的天顶 TurbosPort 模型这样的一些较旧的手摇式计算器，有时被描述为 " 膝上型电脑 " 、他们的规模而且重量了太棒作为这一个类目。
膝上型电脑通常涉及一个设备组或者从能索价设备组的一个外面的交直流连接管当也的时候提供能力给计算机本身。
当做个人计算机，膝上型电脑与一部桌上型电脑个人计算机相同的任务是有能力的，虽然他们为相同的价值典型比较不强力。他们含有与他们的桌上型电脑类似版本类似，而且执行相同的职能，但是被小型化而且将作为移动的使用和有效率的耗电量最佳化的成分。膝上型电脑通常有液晶显示，而且他们大部分使用不同的内存条作为他们的撞槌。（例如，如此-DIMM 代替较大的 DIMMs）除了一个内建的键盘之外，他们可能为输入利用 touchpad（也当做 trackpad 知道） 或者一根磨利根，虽然一个外面的键盘或者鼠标通常能是附件。
使用类型有时称使用的为笔记型电脑的次类型含：
超轻便的
膝上型电脑用荧屏典型地少于 12 寸对角的和一个少于 1.7个公斤的重量他们的键盘通常不是足尺。他们的主要听众通常是商务旅客，需要小的，明的膝上型电脑。超轻便的时常很高价而且收容储存能力的 CPUs 而且几乎总是已经整合图形。
薄地-和-光
膝上型电脑通常秤重在1.8 公斤和2.8 公斤之间以一个在 12 而且 14 寸之间的荧屏规模对角的。
中型的膝上型电脑
这些通常有 15 荧屏 - 15.4 寸对角的和一个大约 3-3.5个公斤的重量他们通常为较小的大小和较长的设备组寿命损失一个小计算能力，虽然长度和宽度通常被荧屏规模决定。
桌上型电脑复位计算机
意谓的　强力的膝上型电脑被主要地在一个固定的位置中使用而且被稀少地携带出自由于他们的重量和规模； 后者提供提供强力的成分和一个大的荧屏较多的空间，通常测量 15 寸 15 寸更多。桌上型电脑复位倾向于已经有限制的设备组寿命，很少非常的三小时，因为硬件没被将作为有效率的能力使用情况最佳化。
发展历史膝上型电脑/ 笔记型计算机前的　是技术上可行又类似的观念被计划，最特别地爱伦凯的 Dynabook 概念，在 1970 年代早期在全录 PARC 发展了。
第一个市场上可以买到的手摇式计算器在 1981 年是 Osborne 1，哪一个使用了商业本票/M 操作系统。虽然它与今天的膝上型电脑相较是大又重的，但是藉由一个极小的 CRT 显示器，它有一接近-革命的影响因事，当职业的能够第一次和他们拿他们的计算机和数据之时。这和其他的 " luggables" 以或许是第一个手摇式计算器的方式激发了，全录 NoteTaker，再在全录 PARC 发展，在 1976 年； 然而，只有十个样品被建造了。Osborne 有关可港口缝纫机的规模的事，而且重要地可能被继续一个商业的飞机。然而，在电池上运行 Osborne 是不可能的； 它必须被插电。
比较持久的成功是在 1983 年引进的 Compaq 轻便的，来自 Compaq 的第一个产品，，藉着计时 IBM 公司个人计算机变得标准的平台。虽然简直不较多的轻便超过 Osborne 以机器制造，以及需要锕能力运行，它跑 MS-DOS 而且是第一个真实的 IBM 公司同本生物.(IBM 公司的自己较迟的手摇式计算器,到达在 1984 年，特别较少的 IBM 公司超过 Compaq 个人计算机-相容[传唤需要])
另外的一个可重视的机器在 1981 年宣布，虽然首先在 1983 年广泛地卖，是爱普生 HX-20.一部普通的手持式计算机，它以一个全过境运输 68 为特色了-主要的键盘，可休整的镍-镉的电池，小的 （120 x 32 图素的） 点点阵式 LCD 以主文的 4个线，每线主文模态 20个字符，撞槌的一台 24 栏点点阵式打印机，一个微软公司基础译印机和 16 kB 显示.（可扩大的至 32 kB)
然而，可以说第一台真实的膝上型电脑在 1979-1980 年是被法案 Moggridge 设计的栅极罗盘 1101，而且在 1982 年比值. 在一个镁外壳随函封入，它引进现在熟悉的 clamshell 设计，在哪一个持平显示装置动叠关闭对抗键盘。计算机可能从电池被跑，而且被装备这 320 × 200 图素的电浆显示和 384个千位元组磁泡存储器了。它不是 IBM 公司-相容，而且它的高价 （美金$10,000) 对专门的应用程序有限制的它了。然而，它很重地被美国军队所使用，和在航天飞机上的 NASA 之前在 1980 年代期间。栅极的制造商后来赚得了可重视的收入通它的专利正直当它的技术革新变成平凡。栅极系统公司稍后被 Tandy 公司 (RadioShack) 买了。
二台其他的值得注目的稍早膝上型电脑是急剧的个人计算机 -5000 和 Gavilan SC，在 1983 年宣布但是首先在 1984 年卖. Gavilan 特别地是第一部计算机当做一台 " 膝上型电脑 " 被销售。它也被装备一个初期的像 touchpad 一样的指位设备了，在键盘上面的一个面板身上安装。像栅极罗盘， Gavilan 和骗子在 clamshell 情况被收容，但是他们部分 IBM 公司-相容，虽然主要地运行他们自己的系统软件。两者都有了 LCD 显示装置，而且可以对可选择的外面打印机连接。
1983 年也看见或许是最大的事物开始-销售稍早的膝上型电脑， Kyocera Kyotronic 85，多对以前爱普生 HX-20 的设计亏欠. 虽然它在日本起先是一个缓慢的卖主，但是，它很快地被 Tandy 公司 公司、 Olivetti 和 NEC，看见它的电位许可了而且当做港外待运仓收货制度 -80 型号 100 行 （或 Tandy 公司 100） 、 Olivetti M-10,NEC 个人计算机 -8201 分别地销售它.[2] 机器涉及标准的自动接听电池。Tandy 公司 的内建程序，含一个基本的译印机，一个文字档编辑程序和一个终止的程序，被微软公司供应了，而且被认为到已经部分地被比尔.盖兹所写他自己。计算机不是 clamshell，却提供在一个全游历键盘上面的一个可倾斜的 8个 × 40 字符的 LCD 荧屏。藉由它的内部调制解调器，它是一个高度地可港口的通信终端机。由于它的可移植性、好设备组寿命 （和复位的安逸） 、可靠度 （它有没有感人的零配件） 和廉价 （只要美金$300) ，模型高度地被视为，变成在新闻记者之中的一个我的最爱。它用 30 × 的大小 21.5 × 4.5 cm 衡量得比 2 公斤少了。（12 × 1.75 寸 8.5 ×） 起始规格包含了 8 千位元组的撞槌 （可扩大的至 24 kB) 和一个 3 MHz 处理机。机器是关于证券笔记型的规模的事实上，但是期还没有继承使用，而且它通常被描述为一部 " 轻便的 " 计算机了。
在第一台商业的 IBM 公司-相容的膝上型电脑之中的　是 IBM 公司个人计算机可转换的，在 1986 年引进了，而且二个日本东芝公司模型、 T1000 和 T1200，在 1987 年引进了。虽然有限制的以叭塌叭塌响为基础的 DOS 以机器制造，藉由被储存在只能读的存储器的操作系统，日本东芝公司模型很小而且点燃充足在背包中被携带，而且可能是市场上最后一笔交易铅-酸的电池。这些也引进那现在-标准 " 履历 " 对以 DOS 为基础的机器功能： 没有有每次被重新开始，计算机可能在期间之间被暂停。
在一个大规模上的第一台膝上型电脑成功的进来了大的部分借着美国空军由于一个征询方案 (RFP) 在 1987 年. 这合约会最后引导超过 200,000 的购买膝上型电脑。供应这合约的竞争猛烈地被竞赛和时间的主要个人计算机公司； IBM 公司、日本东芝公司、 Compaq 、 NEC 和天顶数据系统 (ZDS），冲开发膝上型电脑试图获胜这交易。ZDS，早地用国税局嬴得一个划时代的交易作为它的 Z-171，为它的 SupersPort 级数被裁定这合约。SupersPort 级数本来与一个 Intel 公司 8086 处理机、双重的软式磁盘磁碟机、 backlit 、蓝和白的 STN LCD 荧屏、和一个 NiCD 电池组一起开始。稍后模型以一个 Intel 公司 80286 处理机和一个 20 MB 硬式磁盘为特色了。在这交易的能力上， ZDS 在 1987 和 1988 年变成了世界最大的膝上型电脑供应商。
ZDS 在设计和这些膝上型电脑的制造的中与 Tottori 三洋合伙了。因为它是一个主要的火印和一个亚洲 OEM（正本设备制造商） 之间的第一个交易，所以这一个关系是值得注意的。在时间、 Compaq 、 IBM 公司、日本东芝公司、 NEC ，等等全部设计了而且制造了他们自己的机器。然而，在 ZDS 的成功之后要约其他的关系，像 Compaq 和公民，很快按照。在这次日本工程学的性质和制造的连同美元的能力关于日圆 （典型地大约 130 Yen=$1） 对日本的供应商驾驶最多的火印。公司，像是三洋、 Tottori 三洋、公民和 Casio 很重地全部参与这企业作为 OEM。然而，中间 1990 年代，一个减弱的美元和 Taiwanese OEM ，像是 Acer 、量子、 Compal 、 Twinhead 和 Chicony 的上涨生存力快速地引导供给碱走向从日本移转到台湾。加添地，打上烙印哪一个是更敏捷的而且被信赖了比较少的在内部的工程学，像是通道、戴尔和微米上开始很快地对领导阶层上涨。组合，像是戴尔/Compal 和通道/量子最后变成了发电所合伙关系而且非常成为 Taiwanese OEM 的突起的因素作为个人计算机制造的中心了从大约 1995 向前的。
另外的一部值得注意的计算机是被克莱夫 Sinclair 商标设计的剑桥 Z88，在 1988 年引进. 有关证券的 A 4 纸张的规模，也，它涉及标准的电池，而且包含了基本的试算表、文字处理和通讯计划。它预料了手摇式计算器的将来小型化； 并且，当做一个以只读存储器为基础的机器以一个小的显示装置，能 - 喜欢港外待运仓收货制度 -80 型号 100- 也被预期如个人数传助理的一个先驱。
在 1980 年代底之前，笔记型电脑正在商务人民之中变成常用。NEC Ultralite，在中间 1989 年解除，第一台笔记型计算机也许是，秤重只是超过 2 公斤； 代替一叭塌叭塌响的或硬式磁盘机，它包含了一个 2 百万位元撞槌磁盘，但是这减少了它的公用程式和它的规模。含硬式磁盘机的第一台笔记型计算机是那 Compaq 的那些 LTE 级数，接近那年度底引进了。真正笔记型的规模，他们也以 CGA 解析度以 backlit 显示装置为特色了.（虽然不 CGA 颜色）
第一个 Apple Computer 公司机械设计在活动中被使用是这 1989个麦金塔轻便的.（虽然一个 LCD 荧屏在 1984 年是可运输的苹果电脑 Ⅱc 的一个选择项） 实际上 " luggable",由于它的散装，雨衣轻便的为它的无罪动态点阵式显示器和长的设备组寿命被称赞，但是一个贫民的卖主。缺乏一台真实的苹果电脑膝上型电脑，数个的相容机器，像是对外膝上型电脑是有效的作为雨衣使用者； 然而，为着作权理由，使用者必须供应有也购买一个新或使用的麦金塔的一组雨衣只读存储器，通常意谓了。
苹果电脑 PowerBook 级数，在 1991 年十月引进了，提倡了在膝上型电脑，像是键盘的募集资金上是现在事实标准的改变，室为手掌盈余，和内建指位设备 （一个跟踪球) 的内含物. 下列的年度，IBM 公司解除它的 Thinkpad 700 C语言，以一个类似的设计为特色.（虽然以一个区别性的红色 TrackPoint 指位设备）
较迟的 PowerBooks 引进那第一的 256 彩色显示的 (PowerBook 165 c,1993），和第一真实的 touchpad，第一的 16个位元稳固的记录，和第一个内建的以太网络网络连接管 (PowerBook 500,1994）.
1995 夏天在笔记型计算的历史中是一个可重视的转折点。在八月那年度微软公司引进了 Windows 95。微软公司把许多能力经营控制放在操作系统的是第一次。在这点每个火印之前使用了商业惯例生物活素，驱动器和在一些外壳，应用导向积体电路，将它的机器的设备组寿命最佳化。因为它非常减少了他们的能力改革，所以在微软公司之前的这变动以笔记型伪钞制造犯的观点而论是争论的； 然而，它在单一化而且稳定笔记型设计的特定面方面确实服务它的角色。Windows 95 当做基本的平台也在流动计算中预示光盘的重要而且创议了对 Intel 公司 Pentium 处理机的漂移作为笔记型。通道独奏是与一个 Pentium 处理机和一个光盘一起引进的第一个笔记型。藉由也以它是第一台三纺锤 （光学、叭塌叭塌响，和硬式磁盘） 的笔记型计算机的一个可移动的硬式磁盘和软式磁盘机为特色。通道独奏在市场的用户片段里面极端地成功。在概略地同一个时间内周期戴尔宽容度、日本东芝公司宇宙站和 IBM 公司 Thinkpad 正在用指向社团的市场的以 Pentium 为基础的二纺锤 （硬式磁盘和软式磁盘磁碟机） 的系统达成很大的成功。
旧的 （1997） 微米 laptopAs 技术在 1990 年代、有用和被增加的膝上型电脑的名声期间改良。
相应地价值下降。对膝上型电脑的数个发展特有的很快地被履行，有进展可用性和绩效。在他们之中是：
改良了设备组技术。重的铅-酸的电池与更轻而且更更多有效率的科技一起撤换，第一镍镉或者 NiCD，然后镀镍于金属制的氢化物 (NiMH) 然后锂离子设备组和锂聚合物。