Pokemon SoulSilver Save Hack

Posted 2010.03.20 11.45 in Computers/Internet/Technology by Stephanie

So after taking apart the pokegame and the pokewalker, I put it all back together and have been playing with it now and then. I figured out how to catch more pokemen but couldn’t tell which ones are good or bad…so I sort of go by who’s cuter. My guy Bungee was cute but then he evovled and got bigger and meaner and less cute. I had a hooty that I stuck in the pokewalker and sort of forgot about for a day or two, and he caught a few things. One of them was some kind of frilly fluffy pony thing, and she’s cute so I put the hooty away and have the pony stuffed in the pokewalker. Anyways, blah blah blah.

So I’ve been seeing lots of people saying that they can’t get the precious save-game data out of their pokecartridge, or they’ve been playing on a flashcart and now want to put the save data back into the pokecart so they can use the pokewalker (the IR stuff is hardware, only exists on the real cartridge not the flashcarts.)

This morning I decided to have a look and see what the problem was. I took apart my SoulSilver cart again to map out how it was set up.

In normal cartridges, edge-connector pin 6 is the /CS signal for the EEPROM. (See here for details.) Toggling that line low gives you access to the EEPROM chip. In the SoulSilver cartridge though, pin 6 doesn’t go to the EEPROM but instead it goes to the small MCU. My assumption is that the game is coded so that the /CS EEPROM signal is used to toggle both the eeprom and the IR device with that MCU handling the logic.

Normal backup tools can’t handle this, they don’t know how these cartridges access the save data. However, my solution is very simple albeit requiring hardware hacking. All I had to do was identify which pin on the EEPROM chip was /CS (it’s pin four). Then I soldered a jumper wire from the edge connector pin six to the EEPROM pin four:

Once this was done, I was able to use the NDS Backup Tool and this time it successfully recognized the save as 4Mbit, and copied out properly. I was then able to use that .sav file on my flashcart (Acekard 2i with AKAIO 1.6rc). Furthermore, I was able to take the save file back and write it back out onto the retail cartridge, using this same setup.

Once the save was written back out to the retail cartridge, I simply removed the jumper wire and re-assembled the cartridge. I was then able to continue the game on the retail cartridge & use the pokewalker etc.

If one wanted to make this more elegant, it’d require soldering a SMT microswitch next to the IR transceiver, cut a hole in the top of the cart, then use the switch to control the /CS EEPROM line so you could switch it on or off without having to take things apart and resolder every time you wanted to read/write the save data… too much work for me I think.

I’m just happy to have the ability to backup my game save.

One Comment

  1. Stephanie says:

    Update: Apparently there is an NDS Backup Tool Plus that is able to access the SS/HG saves directly. I’m intrigued but the NDS Backup Tool Plus is $30 and I’ve already got the $20 NDS Backup Tool not-plus.

    I’m betting the Plus version has some flash memory to allow it to be updated, and it definately would have the smarts to know what commands to send to the MCU to get it to activate the EEPROM.

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