DS games on a 3DS or a 2DS

[JWeinCom]

Bman54 said:

JWeinCom said:
The resolution is going to be a bit off cause it's stretched to fit the screen. However, you can (I think by holding starts as it loads) play the games in their original resolution while only using part of the screen.

DS games have never stretched for me. They always play in their original resolution, with a black bar on each side of the screen.

No... they don't... 

The black bars on the side of the top screen are so that the sizes of the top and bottom screen match, since unlike the DS, the 3DS screens are not symmetrical.  But the game is being stretched to fill in the rest of the screen.