In my XNA-4.0-game (which somehow is a bit like MineCraft), I have got some big cubes with small textures (16x16px) on it. By default, XNA just scales them up smooth so there aren't any hard borders. But as the game is a retro game, I want these big pixels. So how do I turn of that interpolation?
Change the sampler state to Point clamp or wrap before drawing.