Quoted from epthegeek:The manual says: "It must be in PNG or JPG format and under 2MB in size. Create a folder named “pinballimages” in the root directory of the USB s ck, then copy your graphic(s) into the folder." It doesn't specify what resolution. It'd be nice if it wasn't being resized/resampled.
1360x768 is "native" right now, but it will scale anything (keeping aspect ratio I'm pretty sure).