Nintendo DS Cart Mod To Make A WiFi Board Flasher

Article Published 2023-04-13

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A few months ago I came across a repair/modding blog where DS carts were used as donors for repairing DS lite WiFi boards (these store the firmware). The blog showed how the flash chips in game carts and WiFi boards were interchangable, which was actually what led me to making the custom iQue WiFi board. There was one other thing on the site that interested me: a mod to turn a DS cartridge into a WiFi board flasher.

To simplify things I'm going to refer to the WiFi board as "board", DS cartridge as "cart". Also note that "save chip" and "flash chip" are the same, though I use both terms for the cart and board, respectively.

Because the board and cart use the same chip, the cart can be tricked into reading/writing to the flash chip on the board as if it were just another save chip. This is done by removing the cart's chip, then wiring a plug for the board (Molex 52991-0308) to the save chip pads. Pins 5, 7, 9, 11, 13, 17, 27, and 29 of the connector lead directly to the flash chip, so as far as the cart is concerned, the save chip is connected like normal!

So now the cart can read/write to boards... but what's the point in all of this? Couldn't you just read/write to your firmware with a plain old DS lite?

While you could get away with soldering SL1 together and writing with fwManager, that's only really good for a single board. If you've got multiple boards you want to set up with a certain firmware, you don't want take off the shell, insert the new board, close the shell, write to the board, then repeat for each board you've got. Or maybe you're feeling a bit daring and you never close up your DS shell for sake of easy access to the boards, leaving everything exposed and risking putting in the battery the wrong way and blowing a fuse.

It's a pain! Thankfully, this cart mod allows you to just plug in a cart to any DS, plug in your board, then open a save manager. You can swap the boards while the console it running, making working with the boards much faster. As someone with over 150 boards to dump (praying I find some new firmware on one of them), this is going to save a lot of time.

An addition, I've found that fwManager will improperly flash my custom iQue boards (probably same goes for legit ones seeing as it's all the same hardware), and I think FlashMe just installs a modified world region firmware. This means a bricked iQue board would be impossible to restore to iQue. I've had to solder the flash chip onto a cart, restore the save, then put it back in the board in order to fix it. However, the fancy cart mod fixes this.

If you couldn't tell already, I loved this idea and wanted to create my own board. Sadly the blog's breakout board for the connector wasn't available anywhere, so I had to make a mock up PCB and get a friend to create some gerber files. I got the PCBs printed, got the connector, and then I got to putting it together. I'm not going to talk about the process since it was pretty boring (just soldering a few wires lol) so I'll just jump to the finished product. Warning... it looks AWFUL.

Yeah wow that is pretty bad... but not as bad as the inside of the cart! I used some shovelware game I found in the $1 bin. I had previously taken the save chip from it for the iQue stuff, and I ripped up one of the traces. I figured this project would be a good way to make use of the cart even after pretty well ruining it.

Notice that far away red wire? Yeah... that's there because of the ripped up trace. It went all the way to some hole on the other end of the board. Silly me. At least I was still able to solder onto it.

Anyways tl;dr I mutilated a DS cartridge to make some goofy thing for writing to DS lite WiFi boards. The whole thing cost $3.30 CAD to make ($1 for the game, $2 for the connector, and $0.30 for the PCB) and it'll serve me well. If anyone for some silly reason wants to make their own, I'd be more than happy to help over email or on Discord.