Saturn to 360 Controller Adapter

May 1st I decided I wanted to tackle a big project. I wanted to do something that no one had attempted before and was beyond my current skill set. I had seen numerous inquiries on the forums from people who wanted to know how hard it was to use “X” controller with the Xbox 360. It always boggles my mind how little people know about this stuff and how 90% of the time they simply assume they can just cut the connector off of any cable, twist some wires together and call it a day. I wanted to do something to show everyone that these things were not impossible, nor were they that simple. I eventually decided to build an adapter that would allow me to use a Sega Saturn controller on the Xbox 360.

Saturn to 360 Adapter Logo

I chose the Saturn controller because the data protocol seemed simple and straight forward but complex enough that the circuit design would be interesting and challenging. I assumed that the converted output from the circuit would work easily with the Xbox 360 controller without any major problems, that turned out to not be the case.

I started off under the assumption that since the data from the Saturn controller was a simply multiplexed across four channels I could use some demultiplexers and get some good results. I didn’t know much about multiplexers/demultiplexer and as it turns out they don’t work the way I thought they did. So this didn’t work out.

Saturn Controller Protocol and PinoutSaturn Adapter First Test using demultiplexers

After the false start with the multiplexer I went back to the drawing board and started researching microcontrollers. I had limited experience with microcontrollers in the past but I knew enough that I knew it would work and that I would be able to figure out how to make it work. I eventually decided to go with a Microchip PIC solution using the PICkit2 and its included microcontroller. The first test was successful.

Saturn Adapter First Test with Microcontroller

After that I did a simple test to interface the microcontroller output to the Xbox 360 controller using transistors. This test was also a success. I had to actually use the guts of an Xbox 360 controller for communication between the console and the Saturn controller due to Microsoft’s security system. All major peripherals, especially the wireless ones have their communications encrypted and require a special chip sold only from Microsoft. This is also the reason no 3rd party wireless controllers have become available yet.

Once I scaled the transistor solution across all of the buttons I soon learned that the transistors would not work as anticipated. while my prior test had seemed to work, it had some side effects that were not immediately apparent.

Saturn to 360 adapter 1st Prototype with transistors

I rebuild the whole section of the circuit between the controller and the microcontroller and I ran a ribbon cable from the controller to the bread board just for my own piece of mind. This actually worked great but I was having the occasional voltage problems since the circuit was so large and drawing so much power. The power issues were worked out by simply adding more batteries.

Ribbon Cable Controller InterfaceSaturn to 360 Adapter Prototype 2a using Analog Switches

This ended up being the final version of the adapter. There were a few loose ends that I never tied up but I had met the goals that I had set out to achieve. I showed that controller adapters were possible albeit not easy either.

To my Surprise this project caught the attention of A LOT of gaming news organizations. The one I am most proud of however is an interview I had with Official Xbox Magazine in the UK. I got two whole pages dedicated to the interview and pictures as well as a teaser blurb on the front cover and main index. It has since been reposed on CVG sans pictures.

Here is a link list of all the other websites that covered it:

If you know of other news sites or corners of the web that ran an article or had some comments on it, let me know.

If you’re interested in the more technical side of the project the project log can be found on the Xbox-Scene forums. There is also a wrap-up post with all the important bits in one place. Another interesting bit is a fellow by the name of SaturnAR posted with some in-depth information on the Saturn analog controller which is well worth reading and he remains the only source of this info that I’ve ever seen.

20 Responses to “Saturn to 360 Controller Adapter”

  • Hey
    This could be a real challenge for you…but had you thought about the possibility of making the controller completely wireless? With the Saturn 3D Analogue pad you could…if you could figure out the interface on it. The lead clips off, so you could make a clip on wireless XBox 360 adaptor with a battery case and XBox Guide button on it, and you would have the ultimate controller! It wouldn’t require modifying the Saturn controller, just a clip on attachment. I wonder how small you could make it…!

  • I remember you originally were thinking about extending the project to include other retro console controllers so I keep coming back here to check on further developments. I finally decided to register just so I could ask you to pick this project back up! It’s just such a great idea for 360 and PC gamers – everyone salivated and you got a lot of buzz for it. It’s really amazing compared to most hack jobs… but that also makes it a little difficult for the average hobbyist. I *really* want one of course but totally lack the experience to make it – do you know if someone picked up this project or if I could find someone to build one for me at a reasonable price?

  • To my knowledge no one else picked it up, which is unfortunate.

    One interesting thing though is that one of the “teams” who modify controllers for macro functionality was able to control the buttons directly with their chip, as opposed to using an external switch. This ability would open the potential for a circuit about 1/8th the size, small enough to fit inside the controller entirely.

    Unfortunately they never released their code, and I don’t have an O-scope so without one I cant determine HOW to control the pins directly. (without an o-scope it’s analogous to a blind and deaf man trying to teach himself Japanese).

    I did originally plan to branch out into other classic consoles. Right now though I’ve got a few dozen other major projects going, and I don’t really have the tools at my disposal that would make continuing with this one fun or fruitful.

    If I had access to a high powered o-scope I could figure out how the controller actually works, and from there I could develop a more advanced version of this that would be easy enough for me to sell.

    Really I only ever did this project because everyone kept asking stupid questions about controller adapting and not listening to the answers I gave them… at least I never see any stupid questions getting posted anymore…

  • Quote:
    “This ability would open the potential for a circuit about 1/8th the size, small enough to fit inside the controller entirely.”

    Wow, that would be amazing! You could just make adapters that hook directly to the modded XBox controller for virtually any kind of console controller. Sorry but I think I just came a little 🙂 Thanks for whetting my appetite and then denying me food! Please keep this project in mind for the future because the potential is crazy!

    Due to the 360’s security restrictions, I really like the idea of creating a standard interface allowing people to interface with the 360 controller. This would be really great!

  • I have no idea how feasible this is, but would it be possible to connect your adapter through the official expansion port of the 360 controller? The chatpad accessory can obviously piggyback signals using this port, perhaps it would also be able to emulate buttonpress signals?

  • The official accessory port would be cool, I believe it’s just a USB port though…

    Of course it’s not publicly documented anywhere and I don’t have the tools to make it happen.

    This should make you happy though… I’ve contacted the guys behind the acid mods controller hack to see if I could figure out how they’re talking with the 360 controller to see if it’s any different, the rapid fire controller uses transistors, I tried transistors early on but had problems with cross-talk, they use them in a slightly different way than I did, but hopefully I can find some time to talk to the guys behind the spitfire mod (they’re willing to talk but we’re playing phone tag) and figure out if that system is any different and if it would be of any benefit to this mod.

    I also looked into a low pin count connector… the idea of using a 4 segment 3.5mm jack as a mini-serial port would work well for this. Essentially I’d have a small circuit inside the controller that would output to what looks like a headphone jack and then the actual adapters can plug into that 😀

    depending on the info I get from the spit fire guys will determine if I re-open this project or not… basically it comes down to this: If I can streamline it enough that I can make it self contained and of simple enough construction that I can build and sell a few of them then I will open it… if I can’t make it sell-able than it’s staying right where it is.

  • This is *great* news (potentially)! Taking preorders yet? 🙂 Wouldn’t it be possible (with these design changes) to power the adapters from the controller’s batterypack? I suppose the expansion port (since it is USB) could be used for this… or perhaps easier for the user if a single connector with more pins is used? Just food for thought.

    In case you are curious, there is work being done with the chatpad that might be interesting:

    Well, you’ve made my weekend – I hope your discussion goes well!

  • Sorry for the link dump, but you may also be interested in the Universal PCB project:

    It allows arcade controls to be adapted to virtually any console system. He made some interesting design choices that you may consider. By using a connector with more pins than necessary, he can “autodetect” the console system attached (because each console cable has a specific configuration of empty pins). If you are considering making this project expandable to other controllers in the future (fingers crossed) this may be an interesting way to go. For example, you could create a single adapter that plugs into your modded xbox controller (low pin count). The user could buy/make cables to connect their favorite gamepads to the adapter (high pin count). The firmware could automatically determine what type of controller was attached and make the proper signal conversion. So support for new controllers could be added over time through firmware updates and new cable designs. This would be insanely awesome. The creator of the Universal PCB knows a great deal about the signal protocols of most major console controllers – his source code may be helpful if you ever go down that road.

  • I’ll check those out thanks…

  • hey man i was wondering if there was any way i could buy one of those from you i don’t have the skills/knowledge to build it myself

  • I’ve got a lot of requests for this, fact is it’s not really an easy to use “product” right now, just a mess of wires and chips. and it would take a lot of time and money to make another one.

  • Woah, I set my mind the other day on trying to make an adapter to use my Saturn pad on my original xbox. After studying it a little i came with the idea of using a chip that does the opposite of the one in the saturn controller (demultiplexer ive since learned). I started searching on the subject and I stumble on this page. Seems its all been tried already and is WAY more complicated than i ever expected lol. I salute Twistedsymphony for all this great work but i no longer feel like i am up to that at this point.
    Makes me feel like studying electronics to get better at it though.

  • the Saturn decoding is pretty much done for you here.. you could pick up a PIC and a cheap programmer and just flash it with the code I provide, using a newer style “common ground” controller would allow you to get rid of pretty much the rest of the circuit.

  • Hey twistedsymphony, long time no see (XS).

    For whatever reason here lately, I’ve been tinkering around with different controller protocols. The Sony neGcon then PSX controllers first, then the N64 controller (what a timing witch) and then I remembered the work you did on this thing here. I don’t really get assembly at all, and what I know about C could probably fill a thimble, but I’ve been messing with it for awhile now anyway.

    I had the original Saturn 6 button pad working after a little bit, but wasn’t really content with that, so I moved on to the 3D controller. Which started off being a real PITA, until I put the parking brake on. The PIC can run much faster and miss, skip and just plain get all kind of things wrong, so after I drilled it way back to timings closer to how it actually ‘talks’ to the Saturn it was just one step after another then. The 6 button pad can take being run a whole lot faster, but the 3D pad doesn’t like that one bit.

    The first 5 pics and vid are of the work I just did. The rest are from close to 3 years ago when I decided to open one up and poke around in there with a scope to see what was going on. The 3D controller uses Hall Sensors on the ‘Stick’ and L/R Triggers, as does it’s successor the Dreamcast controller, but only the ‘Stick’ is Analog on the 3D, while the DC had Analog triggers as well.

    Anyway, figured this was about the best place to post this since you already cracked open the door here. 😉

  • wow, nice work on getting the analog controller working. Interesting about the mechanism used and the fact that the triggers aren’t analog.

    Thanks for posting up!

  • Put together most of what I learned and such on the standard 6 button controller protocol here.

  • Welcome.

    Yeah there are just a couple of Hall sensors for On and Off on the L and R of the 3D controller. They had the potential to be Analog, and the Saturn has more than enough Data slots for them to have been, but they didn’t go that route for whatever reason and just made then ‘feel’ that way instead, must have just saved it for the DC.

  • Posted up some info on the 3D controller as well, for anyone that runs across this.

  • I’m curious, do you know how the Twin Sticks register? are they similar to the digital or analog controller? I would think they would be more like the digital just because there is no analog functionality to them and they’ve got the same number of buttons as the digital pad.

  • I’m actually curious about this one myself, and if the thing wasn’t so crazy expensive I’d already have one here connected up to see what is different there.

    I know the way the Twin Stick works in game differs from when the Digital pad is used, D-pad up moves forward while on the TS both sticks have to be moved up, so it must be reporting as some other type of controller when it’s plugged in. My guess would be it reports as an Analog stick there, and just uses fixed values for the movements, 255, 128, and 0 in there when the sticks are moved for one direction, center and the other direction.

    The 3D controller does something like this for the L and R Triggers when it’s in the Analog mode. Even though they aren’t Analog, they each have a full Byte for it, but unpressed the values read as 0, and pressed they are 255, but there’s no middle ground there at all on them as the controller isn’t made for it.

    If you, or anyone that happens across this, has a Twin Stick and VO game that’s just sitting around, or is also curious about how it works, I wouldn’t mind borrowing it for a few days and seeing what it looks like on the Logic Analyzer. No screw would be touched on it at all, unless I have permission to open it up fro pics and a look see, but it’s all done using an extension cable I tap into so the thing wouldn’t be ‘violated’ in any way.

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