Hacking the Game and Watch Super Mario Bros.

I got lucky and received my Game and Watch Super Mario Bros. one day early – and immediately started hacking it! In this video we will teardown the device, take a look inside, and find how we can put our own, customized ROM onto it!

– Twitter:
– Twitter thread:
– Game and watch scripts:

– STM32H7B0 Reference manual:

Also many thanks to SciresM ( ) on Twitter from telling me that … basically exclusively uses AES-CTR!



  1. I always find it funny when the likes of Nintendo go way overboard with their old school tech and expect it not to be hacked lol.

  2. Hey! Do you think it's possible to change the display size?
    Kinda curious to put it on a large screen.

  3. so… the usb data pins are disconnected? lol we can design a flex pcb that ties into those pins connects a interface chip to allow communication with both the flash and microprocessor… pretty sure it will end up on aliexpress soon

  4. THANK YOU. 50€ For 1 old Game???….. Nintendo played with our nostalgia but we are smarter… ♥️♥️♥️♥️

  5. I believe this encryption scheme is called XOR-based one time pad. That XOR stream you inferred was essentially the “one time pad”. The weakness in the implementation here is that there was no protection from using the one time pad multiple times because you could change the contents of the flash. Thanks for the super interesting video.

  6. Let me get this straight. They are patching the original ROM (to update the copyright notice) at runtime rather than just bundling it? What kind of advantage does that give them?
    EDIT: Just read in another thread (thanks to @SkUnreal) it looks like they do this for legal copyright reasons.

  7. You blurred the screen to avoid a nintendo copyclaim. No, I don't think you're a pussy, I just think that Nintendo has never heard of fair use…. ever

  8. A very useful video about hardware hacking that's easy to follow with beautiful graphics! Well done.

  9. You know what you're doing. I admire that. However, I was hoping you would install a ton of games on it or something. Dolphin emulation, what have you.

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