At the Comdex conference in Las Vegas next week Microsoft chairman Bill Gates will launch a promotion for a tablet PC, the marketing seeds of which were planted at least a year ago.

Microsoft officials confirmed on Tuesday that Gates will display and talk about the work being done to create a tablet PC that will incorporate pen-based and voice-based computing with handwriting recognition.

The prototype was first discussed by Microsoft at its Forum 2000 event in Redmond, Washington, last June and at succeeding Microsoft-sponsored events thereafter.

Microsoft officials at that time stated that the unit was at least two years away. The unit will integrate wireless capability and incorporate instant messaging, paging functionality, and Web browsing, and is meant to be used as a fully functioning PC.

"We don't believe users want another companion device. They want the same functionality as they get from a notebook computer," says a source at Microsoft who asked not to be identified.

Last June, a developer working with Microsoft on the project said the device will offer data, video, and voice conferencing. If that is the case, it may explain why the product, according to a Microsoft representative, is at least a year or more away.

In order to accommodate video and voice conferencing with nationwide wireless coverage, the system will need to wait for next generation of wireless services.

There has been speculation that Microsoft's tablet device may use Transmeta's low-powered Crusoe processor. Transmeta officials recently whispered that such a deal was in the works. But Microsoft has not appeared committed to the processor.

"Microsoft has not selected a processor. We are still in the early, early, early stages of development, and I emphasise that what will be shown at Comdex is a prototype," says the Microsoft source.