Gravity
SCBP knows which way up it is, thanks to a chap named Isaac Newton and an apple tree.
With the help of some microscopic engineering in a tiny little chip in pride of place
right in the middle of the board (in case you were wondering why I gave myself the pain
of putting the processor in an unrouteable place at the top), it knows about tilting.
Rather like Don Quixote, in a bizarre kind of way.
Go on. Give a tilt. See what happens. You know you want to.