Microsoft is said to be working on a new pen-based user interface for the somewhat mythical Surface Phone.

Now a new reference to such a shell has been found in the XAML code of Windows 10 Build 17025, a new Redstone 4 build, by Microsoft watcher WalkingCat.

17025 Xaml stack is aware of a "ComposableShell.Composers.Andromeda.exe" thingy — WalkingCat (@h0x0d) October 27, 2017

The structure of the reference suggests that Windows 10 Redstone 4 may offer multiple shell composers, with Andromeda only being one of them. It also suggests that Andromeda will be more than simply a device, but will feature a unique user interface that is deeper than simply a fancy note-taking app. (According to WalkingCat that notetaking app may be called Journal.)

WalkingCat also notes:

welp, since Andromeda is running Windows8828080, I think it does make calls ? — WalkingCat (@h0x0d) October 27, 2017

Thankfully it also appears we should be hearing more about the device as Redstone 4 developers, with rumours that Microsoft’s foldable Surface Phone is heading to the market sometime in 2018. Read more about that device here.