Dell unexpectedly showed up on stage at the Intel Developer Forum on Tuesday and disclosed that the company will ship a dual-core Atom netbook with a hidden sliding keyboard later this year.

SAN FRANCISCO - Dell unexpectedly showed up on stage at the Intel Developer Forum on Tuesday and disclosed that the company will ship a dual-core Atom netbook with a hidden sliding keyboard later this year.

The 10-inch, Windows 7-based tablet will be called the Inspiron duo, according to Doug Davis, the general manager of Intel's Architecture Group, who called David Zavelson, an executive at Dell, to the stage.

Zavelson tried to queue up a local radio station via a globe-shaped icon with local radio stations listed from all over the world, but the demonstration failed using the convention center's built-in wireless.

Zavelson also showed off a high-definition copy of the movie Up that was stored on the tablet, but it stuttered a bit.

Zavelson didn't reveal many of the key details of the tablet, including the included storage and connectivity options  besides WiMAX, which he said would be included.

Gasps emerged from the audience, however, when Zavelson pulled a hidden slider keyboard from underneath the "tablet," turning it into a hidden notebook.

Zavelson did not reveal a price for the Inspiron duo, saying only that it will be out later this year.

A Dell spokeswoman said in an e-mail that the presentation was a "sneak peek" of the duo, and that the company could not offer many other details. "What makes the Inspiron duo unique is its dual personality  it transforms seamlessly between a tablet that delivers an immersive entertainment experience to a ultra-mobile laptop with a keyboard enabling instant productivity on the go," the spokeswoman said.