The Microsoft Firefly is an extremely rare prototype which was the first phone-sized device for Microsoft's "Stinger" smartphone platform.
It was used by Bill Gates at the Telecom 99 show in Geneva to demo the Stinger operating system when it was announced. It was used as part of Bill Gates' keynote address with a demo (see picture below) by Stinger development team member
Ian Ferrall.
Picture credit: Neil Enns
The device was manufactured in-house by Microsoft with the design and build being done by
Matt Taylor.
The picture below is a behind the scenes shot at the Telecom 99 show where Ian Ferrall was preparing the devices for the demostrations at the event.
Picture credit: Neil Enns
Microsoft learned a lot from this early prototype, not least the power consumption characteristics of the chips used in mobile phones. It is believed the Firefly was built using a strongARM processor, which was later disallowed by the development team due to its high power consumption. The chip used in these prototype phones consumed almost as much power in idle mode as it did while active because it was built with a "leaky" high speed process.