Two electronic firms unveiled new tablet computers in Taipei Monday, on the eve of Asia's biggest IT trade fair, as they try to get a slice of a lucrative market dominated by Apple's iPad.

As thousands of industry delegates prepared for the Computex Taipei fair US firm ViewSonic and Taiwan's Shuttle Inc showed off their latest innovations.

ViewSonic, a visual technology firm based in California, introduced what it said is the world's first tablet that is equipped with both Windows 7 and Google's Android platforms.

"While iPad users are aimed for entertainment, our new machine has functions more than that," Kai Wang, a ViewSonic product manager, told AFP during a news conference on the eve of the five-day event.

Kai said the ViewPad 10 Pro will be a simple transition for people who are already used to Microsoft's operation system, adding that he expects much of its customer base to come from those who already use netbooks.

The new tablet, weighing slightly more than 830 grams, will hit the Taiwan market in June and elsewhere in the Asia Pacific in July, with a price tag of up to $799.

IT firm Shuttle Inc from Taipei, meanwhile, showed off its low-priced gadget aimed at the student market.

On unveiling the Shuttle V08, company manager Donald Chen told journalists: "It's true iPad is popular, but it is impossible for Apple to take the world's entire tablet market. There is still room for some tailor-made tablet developers."

With anti-dust and waterproof characteristics, its tablet weighs only 650 grams and is slated to cost just $200.

"Can you see how big the market will be as long as competitors can grab up to a 30 percent share of the global tablet market?" Chen said.

Worldwide sales of tablet computers are forecast to hit 50 million units this year and double to 100 million in 2012, said Chang Li from the Taipei Computer Association, which co-hosts the annual trade fair.

Computex Taipei, which runs from Tuesday until Saturday, is the biggest information technology and communications trade show in Asia and attracts thousands of exhibitors from around the world.