Creating a PAL compatible EarthBound for SNES

One of the things that keeps me hanging around SNES-town is the game EarthBound.
Never played it on real hardware, only ever on an emulator back in the day, so far back.
So now that I have SNES hardware I'm looking to make an EarthBound PAL cartridge.
I do understand there are probably easier ways to do this, but there's no fun if done with a Super Everdrive.
Not saying I won't end up with one of them anyway, but still! :wink-new:

So far I've found the following;
The EarthBound cartridge board is an SHVC-1J3M-20


1 indicates number of ROM chips
J means HiROM
3 means 8KB SRAM (64kbit)
M means it is equipped with a MAD-1 chip

EarthBound is a 4MB cart (32mbit) cart right?

I hope to destroy an EA sports game of some description in the process...
I was wondering if it is possible to replace say an 8mbit chip with a 32mbit chip?
Provided everything else matched, SRAM, HiROM and MAD-1, it should work right?

 

Have you considered buying an American SNES/Super Famicom and just doing a MASKROM swap on a Super Famicom copy of Mother 2? It's a lot easier, it runs at 60hz and comes with the label and packaging.

 

Where's the learning in that! It's definitely on the table for options as a worst case.
I'm just trying to amass knowledge. It sure isn't the easiest way but I'd like to see if I can do it.
Besides, I've only got PAL SNESes at the moment :congratulatory:
I assume they can be region modded / 50Hz / 60Hz modded like the Mega Drives of the time right?

 

You can mod your Pal SNES with a Super CIC switchless mod. This should allow you to play any game from any region without having problems with software protection. The plus part in this solution is that you can play the games the way they were intended to be played, for example Pal Games will work in 60hz without black bars on top and on the bottom. http://www.youtube.com/watch?v=yU9d86tS0ZU

 

SuperCIC you say? I've heard that name floating around before!
Owwwww that video hurt my ears! What was that recorded at? 12kbps?!?!?! :smile-new:
Ah found a DamoMonster video! That should do nicely!

Hmmm, just thinking about Sonic 1 and the slow, slow music and gameplay makes me think this might be a better solution.
Even still, I'll give this a go to see how it turns out - curiosity gets the better of me sometimes.

I guess I'll go with the SuperCIC mod! Incredible that it is switchless as well! The future is now!

 

50/60Hz doesn't affect the SNES anywhere near as much as it affects Mega Drive.

IIRC, it's because the SNES clocks are derived from horizontal refresh, which for 50Hz and 60Hz vertical refresh are very close. 15.625kHz vs 15.750kHz respectively, 0.8% difference, as opposed to a 20% increase from 50Hz to 60Hz.

 

Well I'll make the cart anyway and see what happens. When that fails... err if that fails, I'll SuperCIC it!
That's very interesting to know though - Was the NES the same? Or did Nintendo just learn from Sega's mistakes?

 

To be honest, quite a lot of people quite rightly don't like people hacking up carts to make other ones. I tend to agree with this standpoint and after making a few, I'm very loathe to get the cutters out as I feel I'm destroying history and should just buy a flashcart instead. But if you are determined to do so......

Considering you want them to run in a PAL snes, this means you are probably looking at killing PAL carts, which are more expensive and most are more sought after than the other regions. You can pick up Jap games off eBay *very* cheaply.

I just bought 4 x Jap SNES games off eBay, including P&P and they came to less than $20AUD. That was for a bundle with Super Mario Kart, Super Mario All-Stars and Super Bomberman 2. I'm not going to kill these carts, I've bought a couple of $2 Jap horse racing carts instead, but to give you some idea of the price difference and to discourage you from killing PAL carts.

So, pretty much any HiRom cart with SRAM will do. What I do is open eBay and when I find some cheap Jap carts, I look to see if they meet my requirements using the list that was posted here. Note that anything that's HiROM, at least 16Mbit and has 64kbit or more SRAM will probably be a good donor.

You want a HiROM cart as it's a pain in the balls to convert between the two, 16Mbit will mean there *should* be enough address lines available, but you may find that it is split into two chips rather than one, meaning you'll have to use two EPROMs instead of one. You might find that the game won't boot on carts with more than 64kbit or SRAM, but you can rectify that by hacking out the SRAM check in the game code or cutting a few traces to the SRAM chip and hardwiring some of the upper addresses to ground.

Don't forget to check whatever ROM you want to use in a high-accuracy emulator first AND *remember to remove the header* before burning it to EPROM.

If it's your first time making one of these and messing around with EPROM's, personally I would fit a socket instead of soldering the chip to the PCB. You'll probably mess up something and it's a lot easier to just pull the EPROM out and reprogram it than to desolder it. Also I'd look into the 'swapbin' method as it's a hell of a lot easier to faultfind 2 wires than 8+.

Honestly, unless you already have an EPROM burner and a strong desire to spend hours squinting at tiny PCB tracks, desoldering, faultfinding etc, then just get a flashcart.

 

Thanks for the advice, you bet I have an EPROM burner and UV eraser and I love trace work.
Why just last night I fixed up the Aiwa Mega-CD BIOS socket I almost completely destroyed dumping this little guy here.
I tend to find that I learn best by fiddling with things.

Horse racing cars sound to be a formidable foe to EA sports games! :encouragement:
I'm not a collector of games, but I do understand your strong feelings - I'll leave the poor PAL carts alone!
And yes I'll definitely be going the socket route for when I burn the ROM incorrectly the first time! :friendly_wink:

Thanks for the ideas!

 

The NES suffers from slow/fast audio when you play games on the wrong region console. As RetroSwim said, the SNES doesn't suffer from this problem, before I had my NTSC consoles, I played my games using a converter on my PAL SNES and the audio was normal.

 

Oh! So Sega was a bit slow to the party? :biggrin-new:

 

Gotta go fast!

 

That PCB is mostly used in RPGs, but it's also in NHL 97 - which is a fine candidate for destruction if I ever saw one...

 

Or slow as the case is when playing NTSC Mega Drive games on a PAL console

 

Well I think a quick update is in order. It's been quite a trek, but I can now at least access some of the game play in EarthBound.
Found a few different ways to have the copy protection and region protection trip.

Ended up removing the CIC chip off the cartridge (I have a SuperCIC installed in the PAL SNES currently), and it progresses to the jazzy intro music. Previously I'd just hit a wall. It appears to have been "Movement Script 1" as they call it. How far will I be able to play? Maybe I'll get swarmed by enemies in weird places. Let's find out!

Would that make sense though? Removing a PAL CIC from inside the cartridge and then the game boots? Does SuperCIC handle all that jazz or should I be flashing a 12F629 with the "key" code?

Edit: Are you nuts?




Edit 2: Hmmm, inserting the cartridge backward (chips facing front) results in the save game data disappearing...



Oh dear lord there was over 30 levels per character saved up in there!

 

If you have copy protection issues something is wrong with your cart's SRAM ("WRAM") decoding, or it has the wrong size SRAM.

 

SRAM is 64 Kbit (8KB) on the donor cart, which matches EarthBounds requirements
Everything ran well (for 30+ levels, ~14 hours game play) with the CIC removed off the game cart.
No swarms of enemies anywhere. It just seemed to be working as one would expect a real cart to work.
Does SuperCIC (Lock) remove the need for having one on the cartridge?

Oh I should note that converting the ROM to PAL let's it catch one of the copy protection checks.
It freezes with a warning just as the jazzy music begins. Obviously doesn't like the code being jiggled!
Can't believe I nuked my games by putting the cartridge in backward though...

 

Lucky you didn't blow the SNES fuse....

 

I'd rather the fuse blew! I've got picofuses everywhere, no save games though!
Oh wait, I'm in a sombre mood, errr
There, that's better!