auto switching snes mod (I did it!)

Started by phreak97, December 31, 2007, 02:40:11 PM

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looking in tommii's thread over in console mods, someone mentioned a line which changes state depending on the region of the cartridge. i havnt gone experimenting yet, but my idea is to use the security information to switch the refresh rate, and maybe the lockout aswel.
is it possible to have the cic chip running without communicating with the rest of the snes? i used a transistor inverter in place of the cic in a nes, perhapse something liike that could be part of this idea, i used to have a snes that had a strange mod which involved the complete removal of the cic, ill see if i can get the photo i took of the mod.

is there a set of pinouts for the ic's in a snes that i could look at somewhere? i already have a modded snes which id be happy to remod to experiment with.



so far works on a pal snes.

ill refine it and post a proper explanation.. but basically starting from a fresh PAL snes, no mods, you lift pin 10 on the cic, wire pin 10 to the normal 50/60 pins on the ppu's, then to make it boot, put a resistor (i used 12k cos i ran out of 10k ones) between the pad under pin 10 and pin 18 (or any 5v), then attach a capacitor (i used a 220uF electrolytic just cos) connected between ground and the pad under pin 10.

an ntsc snes would likely need an inverter (easy) between the cic and ppu's to make it choose the right refresh rate. if i can get my crusty old ntsc snes back from wherever it is, illl see what it needs.

this is my prototype idea which i have tested and works perfectly with the games i have tried. id like to learn more about the cic wiring still cos i swear mario rpg worked when i had a disabled cic in this snes, but it doesnt now.. further testing to come i guess.

far out, from my point of view that was the worst time for server death.. this is the first really good mod i've ever figured out myself, im dying for feedback:P

i've also wired in a dual coloured led so that when pal (native) games are running the led is the regular red and when ntsc games are in it lights orange. honestly i dont remember how i did that, that bit of the mod has been in my snes for ages, it used to be attached to my old switched mod, but basically its set up so that the green side of the led is activated when 60 is activated, and simply not activated otherwise. the red side is always on. the mix makes it orange. like i said, i dont remember how i did it, but i know i needed an inverter for some reason.. i think that led has two ground legs and one positive, that would make sense for needing to invert the 5v going to the ppus to then ground the green leg of the led.. pretty sure thats how i did it now. not to mention driving the led with a transistor instead of a logic line.

one think i noted with this mod, if a native game doesnt make a good connection and fails the security check itll start in 60hz, much like the nes flashes with dirty carts. this is the only problem i have found.


..i thought people would actually be interested in this one :(


I thought you were going to post a proper explanation?  We're all waiting for you.  =(


i still can, i just got put off a bit by the complete lack of enthusiasm.

what program is recommended for drawing up diagrams like this? i did a megadrive colour mod ages ago and i wish id drawn that up now too.
and how would i show lifted pins and the pad underneath as seperate connections?


GameSX has never garnered the same kind of enthusiastic crowd that some other sites have.  It's partly my fault I'm sure, but the result is I've got ten years of mods and hacks and crap on this site and I basically get no feedback about it.  Once or twice a year someone will say they've benefited from the site, but that's about it.

So, sad to say, you're unlikely to get much feedback from posts made here either.  I love to see the mods and I love to put 'em on the main site, and based on the hits I get (millions per month) it's valuable to a lot of people.

You just won't hear about it.


I just wanted to add my agreement with Lawrence's observation. Remember when the hit count went through the roof over the Wii RGB and VGA mod? The subset of gamers who are also brave enough to do their own modding is uniquely antisocial. We don't talk to each other. It's a wonder I'm typing this post now.

Don't be discouraged. The thing about nuts like you and me is that we also can't shut up. You're obviously interested in sharing, so I would like to encourage you to keep doing so. The reward is having done it, and it's not about getting credit or feedback.


I'm thankful for the Genesis AV port pinout here, both revs.  I was able to hook up a Component video transcoder directly to the jack with that information..


haha, alright, point taken, i've already taken photos of my mod, but without a decent diagram theyre not going to be too useful, i crammed it so tight that you cant see whats wired where under the cap and resistor.

anyone know a decent program to draw diagrams? i tried doing it with expresssch, but since thats for schematics, it didnt turn out so great, plus when you make a custom ic you have to draw in each leg individually :X and i want to put the ppu's in the diagram....


I do all my schematics in PaintShop Pro.  It's...  somewhat less than ideal. 

Someone recently pointed me towards bsch3v, which I quite like, though I've only played with it for a few seconds.


I found this interesting, but since I won't use it myself, I didn't post.

You guys also have to realize, most who DO make use of what is available here, don't post because they are discouraged by the obvious experience here.
I know I was, I've been visting the site for over 5 years now, made my own SNES > PC adapter by using pinouts from here then. It was only recently really that I bothered to join the forums and post.


im not getting discouraged, i will at some point post more detailed instructions, i just dont get alot of time.

really the instructions i wrote out to begin with will work, i didnt change my final design from that at all, except i did use a 10k resistor in the end instead of a 12k.

there is a line from the small ic which is near the cic which can be used instead of the cap and resistor i used, i have seen it done in a snes before in a mod where the whole cic was removed, but the place my info was hosted went down permanently.

Edit [I recommend against the wires only mod, mine died after U10 decided to put 12v down my reset line, also this mod will leave your reset button inoperable]:

i just did a bit more looking around, and found this mod, which i used as a basis to eliminate all components. you dont have to remove the cic, but my snes doesnt work with an import mario rpg.

complete wires only swichless mod (pal console):

lift pin 10 on U8, pin 30 on U3, and pin 24 on U2.
wire these three pins together.
once that is done, wire the solder pad under pin 10 on U8 to pin 4 on U10 (do not lift this pin).


i still want to make this work on an ntsc snes..

if anyone hapens to know of an unused inverter or and gate or something else that could be used as an inverter that is already on the snes board, please let me know.. the trouble i have is that the output from an ntsc cic will set 50hz for ntsc games.. i still would like to not use any components.


holy crap i just booted mario rpg.. new mod to come.


hey phreak97,

I registered to express my interest in what you do. Can't wait to see the photos and the schematics to try this mod and give you some feedback.
I really think this mod could be of great interest. Would you allow me for instance to translate your tutorial in french ?


thanks:D i've got no problems with you doing whatever you want with the tutorial, if i ever get it made. i believe in sharing content online:) so long as you dont try to say it's your own, i dont mind if it has my name on it or not, either.

i've hit a problem though.. mario rpg works with pin 4 lifted, but i cant figure out a way to make that happen only for wrong-region games.. at least not with the all-wires mod i wanted. also the place that website told me to connect the ppu reset lines to is at almost 6.5v.. i dont like that at all, thouh i mist admit it works beautifully. im just stuck because i cant find any information.

is there a full schematic out there for any snes model? im sure the logic lines im looking for are there somewhere, its just so far im pretty much just searching in the dark..


First up, this is a fantastic discovery phreak, and once my skills have improved I'm really looking forward to trying this. :)

Secondly, there's a place called that has SNES schematics. However 1) they're for sale and 2)  I have no idea how complete/good they are.

Just a quick question about your autoswitch discovery - does this mean that a PAL cart will make the unit boot up in 50Hz and NTSC ones in 60? Or all in 50, or all in 60?


thanks, ill have a look there in a minute..
pal boots in 50, and ntsc boots in 60. otherwise wheres the auto bit? :P

im working on the mod again now.. so this post is ending about here



i dont know what hapened, but the snes was dead before i started.. maybe it didnt like being open on my couch for however many weeks.
either that, or the probe voltage for the continuity beep setting on my multimeter fried something....

freaking damnit, so pissed off..

anyone got loose pal snes lying around? im looking at about a $10 price tag.
even if someone just has a working motherboard, ill take that.

the only other snes i have here to play with is an american one.. ill take a look in it though, maybe i can figure out how to turn it pal.


it seems that something i did made that 6.whatever volt line go up to 12v, which sent 12v down the reset line of one of the ppus.. i guess that board is junk now.. so sad, it's been with me for a long time.



i picked up two snes consoles for $5 each today, so ill likely be resuming my mod in the near future.

dont expect wires only this time though, im gonig to forget that, it was too dodgy for my liking.. nothing complex though, resistors caps and probably a tranistor for pal.. ill also do one for ntsc with a transistor inverter in there somewhere. this one will work with my copy of mario rpg i hope, can anyone help me identify what version i have? ill google when the time comes, but if someone already knows the versions id welcome the post:)


basically the death of my old snes has put me off a bit, and i now have a half complete 80's arcade cabinet as my main project and havnt had much time for that either..

if someone would like to pick up where i left off i'd be more than happy to help with any information i can give.. im fairly confident i can pull off an auto switching snes mod which is compatible with mario rpg.. though it's possible my copy works on a pal console anyway.. i also think i could adapt the mod to change to non-native for just long enough to pass the region check then go back just after.. meaning people with single refresh rate tv's can make use of it.

something i discovered while doing this mod, was that out of my ntsc games, mario rpg and super bonk would not play on a pal console no matter what i did.. in the end i found it was because the import adaptor i was using to extend the cartridge slot was doing something funky to the wiring (both games worked if i plugged them in with the case off my snes). in the end i opened it up and rewired it to be a straight through adaptor, which worked.
now, im wondering how many people have unknowingly run into this problem and thought it was cos mario rpg has almighty region coding... is it possible that the tech scene isnt that smart afterall?

Tiido Priimägi

How about taking the lockout chip form the cart and putting it into your machine ?

I'm not familiar with SNES yet... I'll get one in near future...
Mida sa loed ? Nagunii aru ei saa ;)


no, because then there wont be a signal to see what region cart is in there.. getting the games to work wasnt the problem.
i also want this to be a mod which people can make with everyday components, i hate ruining carts.


just a note, it's likely he reset button wont work correctly following my instructions above, it needs to be rewired to bypass the cic.
just thought about it the other day when i looked at a snes schematic.


Quote from: phreak97 on January 27, 2008, 04:05:54 PM
..i thought people would actually be interested in this one :(

(bit of a bump).  Well.....uhh....congrats?  I'm more of a "use switches" type of guy because then I have more control over what's going on.  All the stuff in my room is rigged where I can easily switch wires/circuits on/off so when something isn't working right it's easy to test where the problem is.  And it's not exactly much work to flick a couple of switches to get my stuff to do what I want.  Honestly if I was THAT lazy then there's NO way I'd be into modding/hacking/building/whatever you call what I do.


I've seen people flash switchless mods around before, but usually they just use the reset button or something to change modes, i dunno if anyone else spotted it, but the reset button is a switch too (only a hint of sarcasm?:P). mine's truely switchless in that it requires no human interaction at all, i thought that was a decent acheivement.

also i figured people on here are people who enjoy modding and would be interested in something out of the ordinary.

i designed the mod with the idea that even if harder to mod initially, it was foolproof, and anybody would be able to use it without even knowing a mod was there. my goal was a truely universal snes in that you plug anything in, and it just works. (never got around to testing some of the harder to work imports, though the cic is technically still active and probably still communicating with the cart (depends how it acts when it thinks it's pulling /reset low, im not sure), so they might work..)

also, I'm a collector and have in the past been torn between a cool mod and a completely original console, even if it isnt my console. this way the mod is fully reversable (no holes). maybe I'm the only one who cares about that though..


Holy shit I just stumbled across this, that's an awesome mod! I'm stoked for when you get it finished, I have a ntsc SNES I'd love to do it too but I'm definitely not smart enough to continue where you left off. I'd love to have one like this for my Genesis- I absolutely love having region free consoles or mods that don't require switches or modifications to the cases in any way.


haha, thanks:D chances of a polished guide coming out any time soon are pretty slim though.. gotta wait for my hobbies to cycle back round to console modding, I'm into arcade machines currently:P

also I gave up on a mod with no extra components, theres no really safe way to do it that i could find, so for yours theres likely to be up to three transistors, a capacitor, and at least one resistor.

if youre desperate for it to be done, chuck me a pm with your msn address and i can probably talk you through it if you like.

as far as i could tell, theres no way to check what region a megadrive game is, even if i could use the megadrives security against it like i did in the snes, most import games will run happily at the wrong speed, theres no difference in the way the console runs those games and so no way to switch refresh rate from it.

Tiido Priimägi

phreak97 is right about MD, there's no way to get region free-ness without some manual work... you could wire up a simple counter and tie it to the reset button though, then you press reset couple of times to get the correct region and speed...
Mida sa loed ? Nagunii aru ei saa ;)


you need to fix the reset button too:P i missed that bit.. I used a transistor with the base connected to the reset button output, the collector connected to the reset line to the cpu, and the emitter connected to ground. the reset button comes out of the pad under pin 8 of the cic, so you need to lift pin 8 and connect to there.

in other news, the cic is a delicate bastard, if anyone has any dead snes consoles from other failed mods, I'll give you a bit of money for them, I need the parts.