An "Xbox Watch" prototype has been unearthed and brought back to life, showing what Microsoft had in mind for its first, true smart watch after a failed effort in the beginning of the century.

The first known pictures of the device running appear to show a device with heart rate monitoring, guided app-driven workouts, and GPS tracking.

Twitter user Hikari Calyx posted the pictures, as well as a teardown of the device.

Microsoft's early SPOT watch was capable of passively receiving FM data pushes shipping until 2008. Modern rumors of Microsoft working on a smart watch date back to 2013, with reports of the Apple Watch starting in 2011.