How does the EHOLE wall work?

[SUSEd]

There are saves with simulations that only works inside the EHOLE wall.
How does it works? There is no wiki entry for it.

[jacob614]

It is documented on the page for walls, even if it doesn't have a standalone entry:
https://powdertoy.co.uk/Wiki/W/Elements:Walls.html#E-Hole

Particles inside it have no collision with each other, so easily stack on top of each other. They aren't released until it's powered. Otherwise, they can move around anywhere. It creates some interesting effects, some sims just cover the whole screen in E-Hole to disable collision everywhere.