In a move that marks PC maker Asustek's attempts to take on the popular Apple iPad, the Taiwanese company Tuesday unveiled four new tablet devices, at a news conference that previewed the Consumer Electronics Show (CES) - the biggest trade show that officially kicks off on Thursday, January 6.

The four tablets unveiled by Asus were: the $999-$1,099 Eee Slate; the $399-$699 Eee Pad Transformer; the $499-$799Eee Pad Slider; and the $499-$699 Eee Pad Memo. While the Eee Slate will run the Microsoft Windows 7 OS; the other three tablets will run Google's increasingly-popular Android OS, with the Slider being powered by the newest Android version - Honeycomb.

The Windows 7-based tablet will be released later this month; while the other three Android tablets will be launched between April and June. All the four new Asus tablets boast up to 16 hours of battery life.

The Eee Slate will essentially be a conventional tablet PC running Windows 7, and it features a 12.1 inch 1280x800 IPS stylus-sensitive screen; and an Intel Core i5 with 2 or 4GB of RAM, and a 64GB SSD.

The Eee Transformer and the Eee Slider will both have Nvidia's ARM-based Tegra 2 processor and dual cameras. While the former will have a capacitive 1280 x 800 touch-screen; the latter will have a slide-out keyboard and a 10-inch multitouch screen.

The Eee Memo - capable of showing 1080p video - will be powered by a Qualcomm Snapdragon processor, and will feature a separate mic and phone extender.