The IBM SCAMP project (Special Computer APL Machine Portable), was demonstrated in 1973. This prototype was based on the PALM processor (Put All Logic In Microcode).
The IBM 5100, the first commercially available portable computer, appeared in September 1975, and was based on the SCAMP prototype.
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) CRTEpson HX-20, was announced. 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.
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 $8,150 ($18,540 in current dollar terms) 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 From 1983 onward, several new input techniques were developed and included in laptops, including the touchpadGavilan SC, 1983), the pointing stick (IBM ThinkPad 700, 1992) and handwriting recognition (Linus Write-Top, 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 color 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 soon in the 2000s.
Classification The term "laptop" can refer to a number of classes of small portable computers:
- 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. The first laptops were the size of a standard U.S. "A size" notebook sheet of paper (8.5 × 11 inches), 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.
- Netbook: A smaller, lighter, more portable laptop. It is also usually cheaper than a full-size laptop, but has fewer features and less computing power. Smaller keyboards can be more difficult to operate. There is no sharp line of demarcation between netbooks and inexpensive small laptops; some 11.6" models are marketed as netbooks. Since netbooks, compared to laptops, are quite small in size, CDs cannot be used in these computers.
- Tablet PC: these have touch screens. There are "convertible tablets" with a full keyboard where the screen rotates to be used atop the keyboard, 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.)
- Rugged: Engineered to operate in tough conditions (mechanical shocks, extreme temperatures, wet and dusty environments).
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. These, and sometimes desktop-replacement computers in general, are sometimes called desknotes, a portmanteau of "desktop" and "notebook".
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, and most peripherals are available in laptop-compatible USB versions which minimise the need for internal add-on cards. In the second half of 2008 laptops outsold desktops for the first time.
The names "Media Center Laptops" and "Gaming Laptops" are used to describe specialized notebook computers.
Subnotebook Sony VAIO P series subnotebook. 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); the battery life can exceed 10 hours 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, Palm OS or Internet Tablet OS.
Netbook Main article: Netbook Netbooks are laptops that are light-weight, economical, energy-efficient and especially suited for wireless communication and Internet access. Hence the name netbook (as "the device excels in web-based computing performance").
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" and are targeted increasingly at cloud computingclient computer. While the devices range in size from below 5 inches to over 12, most are between 9 and 11 inches (280 mm) and weigh between 0.9–1.4 kg (2–3 pounds).
Netbooks are mostly sold with light-weight operating systems such as Linux, Windows XP and Windows 7 Starter edition.
A netpad is a laptop which is heavily built on RAM specifications to take on Internet surfing.
Tablet laptop See also: Tablet computer A Lenovo X61 tablet laptop with stylus 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.
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 notebook.
Some manufacturers have attempted to overcome these weak points. The Panasonic Toughbook 19, for example, is advertised as a more durable convertible notebook. One model by Acer (the TravelMate C210) has a sliding design in which the screen slides up from the slate-like position and locks into place to provide the laptop mode.
Tablet laptops have the advantage to offer the keyboard and pointing device (usually a trackpad) of older notebooks, for users who do not use the touchscreen display as the primary method of input.
Components Main article: Computer hardware Miniaturization: a comparison of a desktop computer motherboard (ATX form factor) to a motherboard from a 13" laptop (2008 unibody Macbook) Inner view of a Sony VAIO laptop The basic components of laptops are similar in function to their desktop counterparts, but are miniaturized, adapted to mobile use, and designed for low power consumption. Because of the additional requirements, laptop components are usually of inferior performance compared to similarly priced desktop parts. Furthermore, the design bounds on power, size, and cooling of laptops limit the maximum performance of laptop parts compared to that of desktop components.
The following list summarizes the differences and distinguishing features of laptop components in comparison to desktop personal computer parts:
- Motherboard: Laptop motherboards are highly make and model specific, and do not conform to a desktop form factor. Unlike a desktop board that usually has several slots for expansion cards (3 to 7 are common), a board for a small, highly integrated laptop may have no expansion slots at all, with all the functionality implemented on the motherboard itself; the only expansion possible in this case is via an external port such as USB. Other boards may have one or more standard, such as ExpressCard, or proprietary expansion slots. Several other functions (storage controllers, networking, sound card and external ports) are implemented on the motherboard.
- Central processing unit (CPU): Laptop CPUs have advanced power-saving features and produce less heat than desktop processors, but are not as powerful. There is a wide range of CPUs designed for laptops available from Intel (Pentium M, Celeron M, Intel Core and Core 2 Duo), AMD (Athlon, Turion 64, and Sempron), VIA Technologies, Transmeta and others. On the non-x86 architectures, Motorola and IBM produced the chips for the former PowerPC-based Apple laptops (iBook and PowerBook). Some laptops have removable CPUs, although support by the motherboard may be restricted to the specific models. In other laptops the CPU is soldered on the motherboard and is non-replaceable.
- Memory (RAM): SO-DIMM memory modules that are usually found in laptops are about half the size of desktop DIMMs. They may be accessible from the bottom of the laptop for ease of upgrading, or placed in locations not intended for user replacement such as between the keyboard and the motherboard. Currently, most midrange laptops are factory equipped with 3–4 GB of DDR2 RAM, while some higher end notebooks feature up to 8 GB of DDR3 memory. Netbooks however, are commonly equipped with only 1 GB of RAM to keep manufacturing costs low.
- Expansion cards: A PC Card (formerly PCMCIA) or ExpressCard bay for expansion cards is often present on laptops to allow adding and removing functionality, even when the laptop is powered on. Some subsystems (such as Ethernet, Wi-Fi, or a cellular modem) can be implemented as replaceable internal expansion cards, usually accessible under an access cover on the bottom of the laptop. Two popular standards for such cards are MiniPCI and its successor, the PCI Express Mini.
- Power supply: Laptops are typically powered by an internal rechargeable battery that is charged using an external power supply, which outputs a DC voltage typically in the range of 12–24 volts. The power supply is usually external, and connected to the laptop through a DC connector cable. It can charge the battery and power the laptop simultaneously; when the battery is fully charged, the laptop continues to run on power supplied by the external power supply. The charger adds about 400 grams (1 lb) to the overall "transport weight" of the notebook.
- Battery: Current laptops utilize lithium ion batteries, with more recent models using the new lithium polymer technology. These two technologies have largely replaced the older nickel metal-hydridereal-time clock and to store the BIOSCMOS memory when the computer is off. Lithium-ion batteries do not have a memory effect as older batteries may have. The memory effect happens when one does not use a battery to its fullest extent, then recharges the battery. New innovations in laptops and batteries have seen new possible matchings which can provide up to a full 24 hours of continued operation, assuming average power consumption levels. An example of this is the HP EliteBook 6930p when used with its ultra-capacity battery. batteries. Typical battery life for standard laptops is two to five hours of light-duty use, but may drop to as little as one hour when doing power-intensive tasks. A battery's performance gradually decreases with time, leading to an eventual replacement in one to three years, depending on the charging and discharging pattern. This large-capacity main battery should not be confused with the much smaller battery nearly all computers use to run the configuration in the
- Video display controller: On standard laptops the video controller is usually integrated into the chipset Higher-end laptops and desktop replacements in particular often come with dedicated graphics processors on the motherboard or as an internal expansion card. These mobile graphics processors are comparable in performance to mainstream desktop graphic accelerator boards. A few notebooks have switchable graphics with both an integrated and discrete card installed. The user can choose between using integrated graphics when battery life is important and dedicated graphics when demanding applications call for it. This allows for greater flexibility and also conserves power when not required. to conserve power. This tends to limit the use of laptops for gaming and entertainment, two fields which have constantly escalating hardware demands, and because the integrated chipset is very difficult to upgrade for a standard user, laptops may grow obsolete quickly for use in gaming and entertainment.
- Display: Most modern laptops feature 13 inches (33 cm) or larger color active matrix displays based on CCFL or LED lighting with resolutions of 1280×800 (16:10) or 1366 × 768 (16:9) pixels and above. Some models use screens with resolutions common indesktop PCs (for example, 1440×900, 1600×900 and 1680×1050.) Models with LED-based lighting offer a lesser power consumption and wider viewing angles. Netbooks' with a 10 inches (25 cm) or smaller screen typically use a resolution of 1024×600, while netbooks and subnotebooks with a 11.6 inches (29 cm) or 12 inches (30 cm) screen use standard notebook resolutions.
- Removable media drives: A DVD/CD reader/writer drive is nearly universal on full-sized models, and is common on thin-and-light models; it is uncommon on subnotebooks and unknown on netbooks. CDBlu-Ray is becoming more common on notebooks.
- Internal storage: Laptop hard disks are physically smaller—2.5 inches (64 mm) or 1.8 inches (46 mm) —compared to desktop 3.5 inches (89 mm) drives. Some newer laptops (usually ultraportables) employ more expensive, but faster, lighter and power-efficient flash memory-based SSDs instead. Currently, 250 to 500 GB sizes are common for laptop hard disks (64 to 512 GB for SSDs).
- Input: A pointing stick, touchpad or both are used to control the position of the cursor on the screen, and an integrated keyboard is used for typing. An external keyboard and/or mouse may be connected using USB or PS/2 port, or Bluetooth (if present).
- Ports: several USB ports, an external monitor port (VGA, DVI, mini-DisplayPort or HDMI), audio in/out, and an Ethernet network port are found on most laptops. Less common are legacy ports such as a PS/2 keyboard/mouse port, serial port or a parallel port. S-video or composite video ports are more common on consumer-oriented notebooks.
Docking stations became a common laptop accessory in the early 1990s. 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 for additional storage and expansion slots became less critical because of the high integration inside the laptop, port replicators have gained popularity, being a cheaper, often passive device that often simply mates to the connectors on the back of the notebook, or connects via a standardised port such as USB or FireWire.
Standards Some laptop components (optical drives, hard drives, memory and internal expansion cards) are relatively standardized, and it is possible to upgrade or replace them in many laptops as long as the new part is of the same type. Depending on the manufacturer and model, a laptop may range from having several standard, easily customizable and upgradeable parts to a proprietary design that cannot be reconfigured at all. The replacability/upgradability of the hardware can be announced as positive by the laptop maker; a few brands sell "barebones" laptops which can be outfitted by the purchaser.
In general, components other than the four categories listed above are not intended to be replaceable; a few, such as processors, follow their own standards but are difficult to replace because of other factors (for example, in the case of processors cooling and access limitations can make upgrades very difficult or impossible.)
In particular, motherboards are almost always make and model-specific: locations of ports, and design and placement of internal components are not standard. Those parts are neither interchangeable with parts from other manufacturers (replaceable) nor upgradeable. If broken or damaged, they must be substituted with an exact replacement part. Those users uneducated in the relevant fields are those the most affected by incompatibilities, especially if they attempt to connect their laptops with incompatible hardware or power adapters.
Intel , Asus, Compal, Quanta and other laptop manufacturers have created the Common Building Block standard for laptop parts to address some of the inefficiencies caused by the lack of standards.