Three leading watch makers will offer wrist watches by the end of the year that make use of the smart technology, which uses a part of the FM radio spectrum to feed the devices with a low-bandwidth but continuous stream of data, the Microsoft chairman and chief software architect said.
The technology can deliver what Gates termed "glanceable" information to the devices such as a weather and traffic report and text messages. He also showed a magnetic device that can be stuck to a refrigerator or a car dashboard to display sports results or a stock ticker.
"It gives you only the information you've selected," he said. "We're not trying to put a PDA on your wrist."
Called Smart Personal Object Technology, or SPOT, the technology was developed by Microsoft's research group and is the culmination of developments in silicon chips, networking and software technologies, Gates said.
The technology could lead to a host of new services that would be beamed to devices running Microsoft's .Net Compact Framework software, he added.
The chip used in the devices runs at just 28MHz, and the watches on show at the exhibition also have 512K of ROM (read only memory) and a small amount of RAM (random access memory).
That makes them only slightly more powerful than the components used in the first IBM Corp. PC, Gates said. The content sent to the devices is written in "a form of BASIC somewhat like the BASIC that ran on the early PC," he said.
"That data gets translated into .net byte code and is sent down the network to the device," he said.
Michael King, a senior analyst with research company Gartner, is sceptical about the SPOT technology, which was first discussed at the Comdex trade show in November.
"We spend a lot of time in this industry figuring out how to do things and showing we can do them, but we have to stop sometimes and ask whether there's really a need for it," he said.