You could argue that, until the iPad came along, everybody liked the idea of a tablet device but didn't know what they'd actually do with one.

As a result, the history of tablet computing is littered with white elephants and false starts. As the old PDA market proved, it's not enough to simply get the hardware built. You've got to have intuitive software and an effortless user experience to go with it.

Finally, the timing has got to be right. As you'll see from some of the milestones in this list, great ideas can flounder if you have them too soon.

1. The Dynabook (1968)

You could say that the idea for a tablet computer was born back in the 1960s. When Alan Kay and the Xerox Palo Alto Research Center dreamt up the 'Dynabook', they envisaged a portable device that would give children easy access to digital media. It was the perfect name for a new and dynamic device that would act as a paper and pencil, artist's easel, typewriter and musical instrument. In short: an OLPC way before its time.

2. GRiDPad (1989)

While we dreamt of a futuristic Dynabook or electronic Star Trek data pad, what we actually got was the hefty-looking GRiDPad. Built by the GRiD Systems Corporation, this early tablet PC ran MS-DOS, supported stylus input on a 10-inch monochrome screen and had enough juice for about 3 hours of battery life.

GRIDpad

[Image credit: vintagecomputer.net]

Impressed? Analyst Andrew Seybold was. "The GRiDPad is a creative breakthrough in laptop computer design", he wrote in 1989. "It may well capture the title of 'the computer for the rest of us'."

But price stood firmly in the way of this computing revolution. If you thought that the iPad was expensive when it launched, the GRiDPad cost a wallet-emptying $2,370. It was followed by similarly overpriced and underpowered rivals, which included the Momenta Pentop (1991), the Compaq Concerto (1992) and the AT&T EO PC (1993).

3. Tandy Zoomer (1992)

The PDA is an important part of the tablet story. While the GRiDPad had been a failure, GRiD engineer Jeff Hawkins hit on the idea of taking the tablet and shrinking it down to a more portable size. Hawkins founded Palm Computing to pursue the project and, together with Tandy and Casio, they produced a touchscreen device called the Zoomer.

Tandy zoomer

But it was still a struggle to get anybody to buy it. As Infoworld's Kevin Strehlo wrote back in 1993: "I still can't recommend depending on a pen-based computing device to anyone but a UPS delivery person or someone who fills out forms for a living."

4. Apple Newton MessagePad (1993)

As I mentioned earlier, timing is everything. John Sculley, the CEO of Apple in the early nineties, coined the phrase Personal Digital Assistant (PDA) to describe the Newton MessagePad. The handheld device appeared less than a year later, featuring an ARM 610 processor ambling along at 20MHz, 640K of RAM and a 336 x 240 display.

Apple newton

[Image credit: www.msu.edu]

Most people agree that Apple's Newton platform was ahead of its time. Three years to be exact, which is how long it took Jeff Hawkins and Palm Computing to come out with the Palm Pilot 1000 (1996). It marked the beginning of the PDA era and a temporary end to any tablet ambitions.

5. Microsoft Tablet PC (2000)

Fast-forward to the millennium and Microsoft teased its idea of a tablet PC during Bill Gates' keynote speech at Comdex. But it wasn't until 2002 that Gates boldly (and famously) stated that: "the Tablet is a PC that is virtually without limits – and within five years I predict it will be the most popular form of PC sold in America." He was more than a little out.

MS tablet

If you look at the success of the iPad, Microsoft got three aspects of its tablet strategy disastrously wrong. First: "the Microsoft vision for a Tablet PC is that it's a full Windows computer" said Tablet PC general manager Alexandra Loeb in 2000. Wrong. "A Tablet PC needed to be the primary PC…" No. No. No. "It's targeted at business computer users who spend some part of their day away from their desks." Again, wrong.

Worse still, what Microsoft showed in prototype form ultimately became a weighty, bland, disappointingly grey device running Windows XP. Full marks for Microsoft's vision, a big fat zero for real world execution.

6. Compaq TC1000 (2003)

Of course, there was a brief moment in 2003 when we thought that the tablet PC's time had come. It had come in the sexy shape of the Compaq TC1000, a silver tablet/notebook with a detachable 10.4-inch touchscreen. It looked the part, weighed the part and, if all you used it for was browsing the web, it acted the part too. But matching Windows XP with a Transmeta Crusoe processor wasn't the wisest of choices. The performance was lousy.

Compaq

[Image credit: Wikimedia commons]

In the years that followed, manufacturers searched for a form factor that would excite more than the usual early adopters and tech journalists. They dabbled with the Ultra Mobile PC (UMPC) in 2006, then the Mobile Internet Device (MID) and the netbook in 2007. But what we really wanted was an iPad (or equivalent). We just didn't know it yet.

7. Amazon Kindle (2007)

While gadget fans waited for somebody to launch a usable tablet that wasn't trying to be a PC, Amazon went off on a technology tangent with the Kindle.

While the first model was underwhelming, it proved beyond doubt that the time was right for ebooks and e-readers to make their move. For Amazon, the Kindle was the perfect way to nudge customers beyond ordering physical books.

Kindle

And by making the Kindle software available on the iPhone, Android, Blackberry, Windows Phone 7, Mac and PC, customers could buy an ebook once and read it on any device they wanted to.

8. Apple iPad (2010)

Apple launched the iPad in April 2010 with a 9.7-inch display, 10-hour battery life, powerful 1GHz A4 processor and access to the biggest app library on the planet. Like most Apple products, it wasn't just early adopters and gadget-obsessed fanboys who slapped down their money and shouted: "I want one!" It was dads, mums, grans and your mates down the pub.

The surf-from-the-sofa, pinch/zoom, Angry Birds allure of the sweetly-designed iPad also brushed over its technical shortcomings. Flash support… (cough)… no camera… (cough)…

Apple ipad

The iPad was followed bravely by the Android-powered Dell Streak and a gaggle of Archos tablets that you'll struggle to remember. Only the Samsung Galaxy Tab made any sort of impression. Samsung cleverly chose to sidestep a direct confrontation with the iPad by delivering a solid, Android-powered tablet with a smaller 7-inch screen.

9. Motorola Xoom (2011)

Technology moves at a brisk pace these days and if you thought the iPad was good, the Motorola Xoom has the potential to take your breath away. It beats down Apple's device in almost every area. Note the 10-inch (1280 x 800 pixel) display, 1GHz dual-core Tegra 2 processor, front and rear-facing cameras and additional SD card storage. It also runs Android 3.0, which is designed specifically for tablets and provides the wind in this perfect technology storm.

Motorola xoom

Find out more about the Xoom and other wannabe iPad-killers.

10. Hybrids and iPad 2 (2011)

The Xoom and its rivals are setting an impressively high standard. So where do we go from here? Will we see even faster tablets; thinner tablets; bigger tablets; smaller tablets and higher resolution tablets? Yes to all of the above. The tablet market is enjoying a frenzied gold rush and manufacturers will be keen to try anything (and everything) to stand out from the crowd.

That's not to say that there won't be more white elephants and false starts. There's little doubt that Apple will pull itself back into technical contention with an updated iPad 2. But the real innovation might lie with hybrid devices like the Lenovo LePad, a standalone Android tablet that becomes a more potent laptop when docked snugly into an IdeaPad U1 base.

Or perhaps there's scope to return to the idea of using dual displays to take advantage of multi-tasking. NEC is already experimenting with this in its Cloud Communicator device, as is MSI. And didn't Microsoft have the Courier dual-screen prototype back in 2009? Maybe they should dust that off and give it another go?

Did you own an Apple Newton or one of its less usable rivals? Are you enticed by the prospect of an iPad 2 or Android tablet? Let us know below…

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