A tablet computer, or simply tablet, is a one-piece mobile computer. Devices typically have a touchscreen, with finger or stylus gestures replacing the conventional computer mouse. It is often supplemented by physical buttons or input from sensors such as accelerometers. An on-screen, hideable virtual keyboard is usually used for typing. Tablets differentiate themselves by being larger than smart phones or personal digital assistants. They are usually 7 inches (18 cm) or larger, measured diagonally.
Though generally self-contained, a tablet computer may be connected to a physical keyboard or other input device. A number of Hybrids that have detachable keyboards have been sold since the mid-1990s. Convertible touchscreen notebook computers have an integrated keyboard that can be hidden by a swivel or slide joint. Booklet tablets have dual-touchscreens and can be used as a notebook by displaying a virtual keyboard on one of the displays.
Fictional and prototype tablets
Tablet computers appeared in a number of works of science fiction in the second half of the 20th century, with the depiction of Arthur C. Clarke's NewsPad, in Stanley Kubrick's 1968 film 2001: A Space Odyssey, the description of a Calculator Pad in the 1951 novel Foundation by Isaac Asimov and the Opton in the 1961 novel Return from the Stars by Stanislaw Lem. The electronic guide The Hitchhiker's Guide to the Galaxy is featured in Douglas Adams 1978 comedy of the same name. Numerous devices resembling tablets were depicted in Gene Roddenberry 1966 Star Trek series and later spinoff series. These fictional portrayal helped to promote and disseminate the concept to a wider audience.
In 1968, while he was a PhD candidate, computer scientist Alan Kay envisioned a device called a KiddiComp, (which he later renamed Dynabook) in his 1972 proposal: "A Personal Computer for Children of All Ages". The paper outlined his ideas for a portable educational device that would have had similar functionality to a laptop computer or tablet.
In 1994 the European Union initiated the 'OMI-NewsPAD' project (EP9252), inspired by Clarke and Kubrick's fictional work. Acorn Computers developed and delivered an ARM-based touch screen tablet computer for this program, branded the NewsPad. The device was supplied for the duration of the Barcelona based trial, which ended in 1997.
Early tablet computers
Main article: Early tablet computers
A tablet personal computer (tablet PC) is a portable personal computer equipped with a touchscreen as a primary input device, and running a modified desktop OS. The term was made popular as a concept presented by Microsoft in 2000 and 2001 but tablet PCs now refer to any tablet-sized personal computer regardless of the (desktop) operating system. Unlike modern tablet computers, traditional tablet PCs usually had a physical keyboard.
Tablet personal computers are mainly based on the x86 IBM-PC architecture and are fully functional personal computers employing a slightly modified personal computer OS (such as Windows or Linux) supporting their touch-screen, instead of a traditional display, mouse and keyboard. A typical tablet personal computer needs to be stylus driven, because operating the typical desktop based OS requires a high precision to select GUI widgets, such as a close window button.
Intel announced a StrongARM processor-based touchscreen tablet computer in 1999, under the name WebPAD. The tablet was later re-branded as the "Intel Web Tablet".
In 2002, Microsoft attempted to define the Microsoft Tablet PC as a mobile computer for field work in business, though their devices failed to achieve widespread usage mainly due to price and usability problems that made them unsuitable outside of their limited intended purpose.