Start with what the much-hyped Microsoft Corp. project code-named Origami is not.

It's not a music player designed to take on Apple Computer Inc.'s mega-popular iPod. And it's not a portable version of Microsoft's Xbox videogame console. And it won't — at least not yet — replace your cellular phone or your regular computer.

Instead, Origami is the moniker for the first iteration of paperback-sized computers that will run Microsoft's regular Windows XP operating system, a person close to Microsoft told The Associated Press.

The person, who is familiar with the plans, spoke on condition of anonymity because the information is still confidential.

The so-called "ultra-mobile PCs" are being targeted initially at tech-savvy consumers who want a smaller computer that is easy to take on vacation, in the subway or anywhere else where a full-sized PC would seem too bulky, this person said.

Microsoft has confirmed that an ultra-mobile PC is in the works, but the company has declined to offer specific details. A Web site set up by the Redmond company, http://www.origamiproject.com, has been teasing would-be buyers with tidbits about the project, and fueling speculation about what the new devices might do.

[Updates to the Web site, posted March 2, showed images of a city, a golf course, a mountain range, a subway platform and the passenger seat of a car, along with text reading: "Hi there. Wondering where to find me? I am here ... I am everywhere you are — but never in the way. Who am I? Find out 3.9.06."]

The early versions are expected to debut at an industry conference on March 9, and to be available to consumers soon after, the person familiar with the plans said.

They will be built by a variety of computer makers, this person said, and are expected to sell for between $500 and $1,000, although final prices aren't yet available.

The computers will generally be less powerful than full-fledged PCs, although they will have all the functionality of a Windows PC, this person said.

The small size means they won't necessarily have a keyboard. Some other small or advanced computer devices let people use a stylus and a touch screen rather than a keyboard to input information.

Microsoft is expecting that people will use the small computers for things like looking at photos, watching movies, finding driving directions and checking e-mail.

For now, at least, they will not have the advanced entertainment capabilities found in computers running the "media center" version of Windows XP, this person said. Those computers allow people to do things like record television.