The history of tablet computers and the associated special operating software is an example of pen computing technology, and thus the development of tablets has deep historical roots. The first patent for a system that recognized handwritten characters by analyzing the handwriting motion was granted in 1914. The first publicly demonstrated system using a tablet and handwriting recognition instead of a keyboard for working with a modern digital computer dates to 1956.

Early tablets The tablet computer and the associated special operating software is an example of pen computing technology, and the development of tablets has deep historical roots.

In addition to a number of academic and research systems, there were several companies with commercial products in the 1980s: Pencept and Communications Intelligence Corporation were among the best known of a crowded field.

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 appearing in Stanley Kubrick's 1968 film 2001: A Space Odyssey, the description of the Calculator Pad in the 1951 novel Foundation by Isaac Asimov, the Opton in the 1961 novel Return from the Stars, by Stanislaw Lem, and The Hitchhiker's Guide to the Galaxy in Douglas Adams 1978 comedy of the same name, all helping to promote and disseminate the concept to a wider audience. Star Trek: The Next Generation also featured extensive use of tablet computers.

In 1968, Alan Kay envisioned a KiddiComp; while a PhD candidate he developed and described the concept as a Dynabook in his 1972 proposal: A personal computer for children of all ages, the paper outlines the requirements for a conceptual portable educational device that would offer functionality similar to that supplied via a laptop computer or (in some of its other incarnations) a tablet or slate computer with the exception of the requirement for any Dynabook device offering near eternal battery life. Adults could also use a Dynabook, but the target audience was children.

Steve Jobs of Apple envisioned in a 1983 speech an "incredibly great computer in a book that you can carry around with you and learn how to use in 20 minutes". In 1985, as the home-computer market significantly declined after several years of strong growth, Dan Bricklin said that a successful home computer needed to be the size of and as convenient to carry as a spiral notebook. He and others urged the industry to research the Dynabook concept. In 1988, Apple, as part of the "Design the Personal Computer of the Year 2000" contest, awarded a project named TABLET, inspired by the Dynabook. This tablet included all the features found in "modern" smartphones: camera, video recorder, microphone, speaker, cellular communication, GPS, and more.

In 1986, Hindsight, a startup in Enfield CT, developed the Letterbug, an 8086-based tablet computer for the educational market. Prototypes were shown at trade shows in New England in 1987, but no production models ever came out. Howard Eglowstein's (one of the Letterbug developers) website

Early devices

In 1987 Linus Technologies released the Write-Top, the first tablet computer with pen input and handwriting recognition. It weighed 9 pounds and was based on MS-DOS with an electroluminescent backlit CGA display and a "resistive type touch screen in which a voltage is applied to the screen edges, and a stylus detects the voltage at the touched location." The handwriting had to be individually trained for each user. Around 1500 units were sold. Linus Write-Top Linus Technologies, Inc.

1988, Hermann Hauser, co-founder of Acorn Computers, with Olivetti, would establish the Active Book Company Ltd, to develop an ARM based pen computer, with GSM connectivity, and utilising a Smalltalk based touch OS. The company would be bought by AT&T, and some technology borrowed for its 1991 EO Personal Communicator.

In 1989, Grid Systems released the GridPad 1900, the first commercially successful tablet computer. It weighed 4.5 pounds and had a tethered pen resistive screen like the Write-Top. The handwriting recognition was created by Jeff Hawkins who led the GridPad development and later created the PalmPilot. Its GRiDPen software ran on MS-DOS and was later licensed as PenRight.

The 1991, Atari ST-PAD Stylus was demonstrated but did not enter production.Atari ST-PAD The Atari Museum

In 1991, AT&T released their first EO Personal Communicator, this was one of the first commercially available tablets and ran the GO Corporation's PenPoint OS on AT&T's own hardware, including their own AT&T Hobbit CPU.

In 1992, Samsung introduced the PenMaster. It was based around the Intel i386SL CPU. As the OS, it used the newly released Windows for Pen Computing from Microsoft. The touchscreen relied on a chipset by Wacom and it used a battery powered pen. GRID Systems licensed the design from Samsung and was also sold as the better known GRiDPad SL.

In 1993, Apple Computer released the Apple Newton, with a 6-inch screen and 800 grams weight). It utilized Apple's own new Newton OS, initially running on hardware manufactured by Motorola and incorporating an ARM CPU, that Apple had specifically co-developed with Acorn Computers. The operating system and platform design were later licensed to Sharp and Digital Ocean, who went on to manufacture their own variants.

The Compaq Concerto was released in 1993 with a Compaq-modified version of MS-DOS 6.2 and Windows 3.1, a.k.a. Windows for PEN, with pen-entry and Wacom compatibility. Functionally the Concerto was a full featured laptop that could operate in pen-mode when the keyboard was removed.

In 1994 media company Knight Ridder made a concept video of a tablet device with a color display and a focus on media consumption. The company didn't create it as a commercial product because of deficiencies of weight and energy consumption in display technology.

In 1994, the European Union initiated the 'OMI-NewsPAD' project (EP9252), requiring a consumer device be developed for the receipt and consumption of electronically delivered news / newspapers and associated multi-media.Outing, Steve (23 October 1996) "Digital Tablet Makes Strides in Europe and US" Editor & Publisher. The NewsPad name and project goals were borrowed from and inspired by Arthur C. Clarke's 1965 screen play and Stanley Kubrick's 1968 film: 2001: A Space Odyssey. 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.The Reading Appliance Revolution, by: Bill N. Schilit, Morgan N. Price, Gene Golovchinsky Kei Tanaka (FX Palo Alto Laboratory), Catherine C. Marshall (Xerox PARC). Published: IEEE 1999-01

In 1996, The Webbook Company announced the first Internet-based tablet, then referred to as a Web Surfboard, that would run Java and utilize a RISC processor. However, it never went into production.

Also in 1996, Palm, Inc. released the first of the Palm OS based PalmPilot touch and stylus based PDA, the touch based devices initially incorporating a Motorola Dragonball (68000) CPU.

Again in 1996, Fujitsu released the Stylistic 1000 tablet format PC, running Microsoft Windows 95, on a 100 MHz AMD486 DX4 CPU, with 8 MB RAM offering stylus input, with the option of connecting a conventional Keyboard and mouse.

In 1999, Intel announced a StrongARM based touch screen tablet computer under the name WebPAD, the tablet was later re-branded as the "Intel Web Tablet"."Intel's NewsPad from Acorn… the saga continues…" The Register, 25 May 1999

In April 2000, Microsoft launched the Pocket PC 2000, utilising their touch capable Windows CE 3.0 operating system. The devices were manufactured by several manufacturers, based on a mix of: x86, MIPS, ARM, and SuperH hardware.

One early implementation of a Linux tablet was the ProGear by FrontPath. The ProGear used a Transmeta chip and a resistive digitizer. The ProGear initially came with a version of Slackware Linux, but could later be bought with Windows 98.

Microsoft Tablet PC

In 1999, Microsoft attempted to re-institute the then decades old tablet concept by assigning two well-known experts in the field, from Xerox Palo Alto Research Center, to the project.John Markoff, The New York Times, 30 August 1999, "Microsoft brings in top talent to pursue old goal: the tablet"

In 2000, Microsoft coined the term "Microsoft Tablet PC" for tablet computers built to Microsoft's specification, and running a licensed specific tablet enhanced version of its Microsoft Windows OS, popularizing the term tablet PC for this class of devices.Page, M Microsoft Tablet PC Overview , TransmetaZone, 2000-12-21 Microsoft Tablet PCs were targeted to address business needs mainly as note-taking devices, and as rugged devices for field work. In the health care sector, tablet computers were intended for data capture – such as registering feedback on the patient experience at the bedside as well and supporting data collection through digital survey instruments.Marcano Belisario, José S., et al. "Comparison of self-administered survey questionnaire responses collected using mobile apps versus other methods." Cochrane Database Syst Rev 7 (2015).

In 2002, original equipment manufacturers released the first tablet PCs designed to the Microsoft Tablet PC specification. This generation of Microsoft Tablet PCs were designed to run Windows XP Tablet PC Edition, the Tablet PC version of Windows XP. This version of Microsoft Windows superseded Microsoft's earlier pen computing operating environment, Windows for Pen Computing 2.0. After releasing Windows XP Tablet PC Edition, Microsoft designed the successive desktop computer versions of Windows, Windows Vista and Windows 7, to support pen computing intrinsically.

Tablet PCs failed to gain popularity in the consumer space because of unresolved problems. The existing devices were too heavy to be held with one hand for extended periods, the specific software features designed to support usage as a tablet (such as finger and virtual keyboard support) were not present in all contexts, and there were not enough applications specific to the platform – legacy applications created for desktop interfaces made them not well adapted to the slate format.

Linux

One early implementation of a Linux tablet was the ProGear by FrontPath, which used a Transmeta chip and a resistive digitizer. The ProGear initially came with a version of Slackware Linux, but could later be bought with Windows 98. Because these computers are general purpose IBM PC compatible machines, they can run a number of different operating systems. However, the device is discontinued and FrontPath ceased operations. Many touch screen sub-notebook computers can run any of several Linux distributions with little customizing.

X.org supports screen rotation and tablet input through Wacom drivers, and handwriting recognition software from both the Qt-based Qtopia and GTK+-based Internet Tablet OS provide promising free and open-source software systems for future development.

Open source note taking software in Linux includes applications such as Xournal (which supports PDF file annotation), Gournal (a Gnome-based note taking application), and the Java-based Jarnal (which supports handwriting recognition as a built-in function). Before the advent of the aforementioned software, a number of users had to rely on on-screen keyboards and alternative text input methods like Dasher. There is a stand-alone handwriting recognition program available, CellWriter, in which users must write letters separately in a grid.