Microsoft unveils Surface, iPad challenger

LOS ANGELES -- Microsoft has unveiled Surface, a tablet computer to compete with Apple's iPad.

CEO Steve Ballmer was on hand to announce the new tablet, calling it part of a "whole new family of devices" the company is developing.

One version of the device, which won't go on sale until sometime in the fall, is 9.3 millimeters thick and works on the Windows RT operating system. It comes with a kickstand to hold it upright and a touch keyboard cover that snaps on using magnets.

The device weighs less than 1.5 pounds and will cost about as much as other tablet computers. Its debut is set to coincide with the fall release of Microsoft's much-anticipated Windows 8 operating system.

Steven Sinofsky, president of Microsoft's Windows division, called the device a "tablet that's a great PC -- a PC that's a great tablet."

A slightly thicker version -- still less than 14 millimeters thick and 2 pounds -- will work on Microsoft's upcoming Windows 8 Pro operating system and cost as much as an Ultrabook, the company said. The pro version comes with a stylus that allows users to make handwritten notes on documents such as PDF files.

Each tablet comes with a keyboard cover that is 3 millimeters thick. The kickstand for both tablets was 0.7 millimeters thick, less than the thickness of a credit card.

Microsoft has been making software for tablets since 2002, when it shipped the Windows XP Tablet PC Edition. Many big PC makers produced tablets that ran the software, but they were never big sellers. -- AP