The iPad's DNA: A Brief History Of Tablet Computing

On The Shoulders Of Giants

Apple is defying the skeptics in the early days of the iPad Era, selling hundreds of thousands of units in the first couple weeks since releasing its tablet device. Could Cupertino, Calif.-based Apple be the first company to substantially bring a persistent but largely peripheral product category -- tablet PCs -- into the mainstream?



If Apple does do it, it won't have done it alone. There's a lot of high-tech DNA in the iPad that can be traced back to pioneering work in areas like handwriting recognition, capacitive touch and mobility, dating back as far as the latter half of the 1800s. Let's take a stroll back in time to recognize the various building blocks that were needed for Apple to achieve its iPad success story.

The Write Stuff

Inventor Elisha Gray's telautograph, patented in 1888 and pictured here in a sketch, is described as "an analog precursor to the modern fax machine." What's that got to do with tablet PCs? For starters, Gray's invention -- for the record, some think Alexander Graham Bell had the idea first -- was a huge milestone in the development of a tablet-style interface for recording and transmitting data such as a drawing or signature made by the sender.



"By my invention you can sit down in your office in Chicago, take a pencil in your hand, write a message to me, and as your pencil moves, a pencil here in my laboratory moves simultaneously, and forms the same letters and words in the same way," Gray said in an 1888 magazine interview. Banks and other organizations continued to use variants of the telautograph well into the 20th century to transmit official signatures remotely.

The First Touchscreen?

Fast forward to the 1940s, when the next great step towards a proper tablet computer was beginning to be realized as inventors and dreamers turned their attention to the development of an interface that allowed the user to input handwriting so that it could be digitalized and reproduced as data that a computer could process. In other words, a touchscreen. One tantalizing hint at the early development of the touchscreen exists in a patent granted to one Hannah C. Moodey in 1940 for the plans for a device, pictured here, described as a "resistive-sheet digitizer for a Telautograph system."



Meanwhile, Vannevar Bush inspired technologists with his 1945 essay "As We May Think," which proposed a computing device called the "Memex" that included tablet functions like handwriting input. By the late 1940s, primitive touchscreens had been developed at corporate research labs, but it wasn't until 1975 that the technology captured the public imagination with the hundreds of touchscreen terminals built by Control Data Corporation's PLUTO project.

Birth Of The GUI

In the early 1960s, the ascendency of the integrated circuit was in full swing and visionaries like Ivan Sutherland, pictured here, were exploding the conventional notions of what a computer interface could be. Here, Sutherland demonstrates his Sketchpad system on the console of MIT's TX-2 computer was taken in 1963.



The Sketchpad was not a fully realized touchscreen, but rather was operated using both a light pen and the command button box under Sutherland's left hand. But the system also represented an equally important development in both tablet and non-tablet computing -- the introduction of the graphical user interface, or GUI.

Of Mice And Pens

The RAND Tablet was another important development from the early 1960s. The RAND Tablet did not have a graphical user interface, but it was "the first two-dimensional writing surface that allow[ed] humans to communicate instantly with a computer through characters printed on a tablet," according to RAND Research. It should be noted, however, that the RAND Tablet was preceded by a similar device called the Stylator that was built by Tom Dimond in the late 1950s.



As computing went mainstream in the 1970s and 1980s with the development of the personal computer, the mouse and keyboard as an input device reigned supreme -- but "pen computing" built around handwriting recognition became a Holy Grail of sorts in the high-tech industry. Despite lots of hype and innovations like Dr. Charles Elbaum's NestorWriter and Microsoft's Pen Extensions for Windows 3.1, pen-based PCs never became much more than a fringe product category.

Going Mobile

So far, we've looked at several technological building blocks that had to be invented before the iPad could come to be, including touchscreens, handwriting recognition and the GUI. Another crucial development was happening concurrently, driven by the relentless shrinking of computer circuitry -- mobility.



In 1968, computing pioneer Alan Kay envisioned what we would now call a mobile personal computer, a lightweight, battery-powered PC with both a keyboard and an option for input by a stylus. Kay called his notebook PC the "Dynabook," pictured here from a 1972 sketch. Of course, it would take Moore's Law (and battery technology) some years to allow for such a device to actually be manufactured -- and when real-life Dynabooks did appear, most favored a keyboard-mouse-based input over a pen.

Tablets For The Masses

Tablet computing arrived in the burgeoning PC market in 1982 when Waltham, Mass.-based Pencept introduced its PenPad computer, which used a digitizing tablet and electronic pen for input and had no keyboard. Pictured here is the PenPad 200 Terminal from 1983. Pencept and its competitor Communication Intelligence Corporation focused on building handwriting and gesture recognition algorithms that worked in conjunction with existing hardware architectures and the MS-DOS operating system.



In contrast, the GO Corporation was founded in 1987 to attempt the decidedly more Apple-like mission of building an entirely new operating system and proprietary gesture-based user interface called the PenPoint OS. The company's funding and roster of talent were impressive but the company ran into competition from Apple and Microsoft, both developing their own proprietary pen computing technology. More critically, consumer demand for tablet computers never really materialized and GO shut down in 1994, having chewed its way through the then-princely sum of $75 million in venture funding.

Padding The Numbers

By the late 1980s, tablet computing still had people excited despite signs of consumer apathy. It was ready to collide with another exciting -- and ultimately far more fruitful -- technology trend, mobility. The result was an eruption of mobile tablets and personal digital assistants (PDAs) featuring touchscreens and handwriting recognition. One of the first such products to hit the market was GRiD Systems' GRiDPad, pictured at top, a portable MS-DOS-based "pen-top" tablet PC released in 1989.



Competition for the GRiDPad came from IBM's ThinkPad, and from Fujitsu's PoquetPad and Poquet PC Plus -- the second of which introduced an integrated wireless LAN for the first time to tablet computing. On the PDA front, Apple began shipping its Newton, pictured right, in 1993. That same year, GO, in partnership with AT&T, released its EO Personal Communicator, pictured left, featuring the PenPoint OS.

Multi-Touch Me Baby

By the early 1990s, many of the building blocks that shaped the iPad -- touchscreens, GUIs, mobility, wireless networking -- were active, marketable technologies, if primitive by today's standards. But one crucial innovation that defines the iPad user experience -- capacitive multi-touch with real-time visual pattern and gesture recognition -- was just being invented.



It may come as a shock to those of us whose first experience of using our fingers to pinch, squeeze and slide objects on a computer screen only dates back a few years, but a Xerox EuroPARC fellow named Pierre Wellner had already developed just such an interface in 1991 -- some 15 years before the first iPhone. Pictured here is a still from Wellner's film demonstration of his "Digital Desk."

The Final Ingredients

Two of the final three pieces of the iPad puzzle came directly from Apple itself. The company's wildly successful iPhone provided both proof-of-concept for a multi-touch interface and the operating system kernel for the iPad. Meanwhile, the more muted success of e-readers, while not a product Apple itself built, likely proved to Steve Jobs that people were ready for a touch-only, entertainment-focused device larger than the iPhone and iPad Touch.



Just as crucially, iTunes and the App Store supplied the sales model that has become the company's lifeblood. Apple doesn't just sell iconic, user-friendly devices. It sells iconic, user-friendly devices that are locked into a gated enclave of downloadable content and newer, cooler software applications. That perpetual money machine may go down as Jobs' most underrated business achievement -- and along with the contributions of many technological pioneers, is why the iPad exists today.