xbox 360 back compatibility

Does the new XBox 360 Slim 4GB have the same XBox1 backward compatibility as the fat model? Better? Worse? Not at all?

since Microsoft has dropped backward compatibility back 3 years ago. im sure that didnt even include the engine to play xbox1 in the slim

BC in the XBox 360 is software emulation so it has backward compatibility.
Though you need an hard drive and not all games are emulated, there's 200-300 games I think that are so far.

So I really dont see why microsoft would remove that software from the slim.

Does anybody actually have one of these that can verify this?