As often happens, additions to software can leak hardware plans and this is what happened in the recent builds of Windows 10 RS5 (due for release in a few months), it seems. A new constant with five (or six, depending on how you count) possible states reveals possible configurations of a folding mobile device, almost certainly what is project 'Andromeda' internally and what will end up as the Surface Mobile (or similar) when it appears on the open market later this year.