Yes, it has the YM2413. It's not the Myth that's different, it's the GBA flash cart that is different (includes a Neo3-SD instead of a Neo2 flash cart). Using the Neo2 512M flash, you should have no trouble playing your SMS games with FM. Remember that the FM chip on the Myth plays the audio through the audio input lines on the cart port (just like the 32X); this means that you don't get FM on the Nomad unless you mod it to mix those lines with the regular audio. The Nomad needs a mod in any case to play SMS games (the line to asset SMS mode exists, but wasn't connected to the cart port).