NG64 Game Conversion

Morden

Somewhere in Europe.,
Joined
Jul 5, 2005
Posts
711
Recently, I got Buriki One, which is my third fighting game for the system. The only one that's left is the first Samurai Spirits game, but it's rather expensive on eBay, which is pretty much what I'm limited to.

This got me thinking. Is it possible to perform a game conversion and convert, say, Samurai Spirits 2, to Samurai Spirits?

The cartridges are basically huge banks of mask ROMs. Replacing these would be a huge undertaking in and of itself, but for this to even be worth the trouble, I'd have to know if there's any type of protection or encryption that would prevent a simple conversion.

Does anyone in here have some expert knowledge when it comes to Neo 64 and its inner workings? I'd like to attempt it at some point, but I would need some help.

Any info appreciated.
 

lachlan

drunk downunder!, aka. Muff Diver.,
Joined
Feb 13, 2005
Posts
18,071
You might be the first person to ever ask this question. Only one way to find out! Socket all of the chips and get burning on those eproms.
 

sr20det510

Baseball Star Hitter
Joined
Oct 31, 2016
Posts
1,262
Maybe awbacon can answer your question. He has done some awesome youtube videos on the system, including one on the motherboard.
 

mmsadda

Just buy my shit. Seriously. You can call me Susan
Joined
Jan 20, 2009
Posts
2,841
Idk if this could potentially help in any way, but I have a spare Hyper cart (I think Buriki) with a destroyed connector. Guessing the guts are intact and you're welcome to it if you want something to pull ROMs from...
 

awbacon

Mizuki's Demon
Joined
Jan 28, 2009
Posts
3,032
Here's your answer, to the best of my knowledge having tested basically every variation of configuration possible.

The Hyper, as far as I can tell, has no security features outside of the BIOS and I/O board.

Region does not matter. You can throw a US bios at a Japanese game, and it boots. Same as the MVS/AES. I've booted my games in Japanese and English no issue (except Beast Busters. I have an english bios, and never bothered to test burn a Japanese version)

I/O boards come in the following configs : Rev 1 and Rev 2 fighting, Korean exclusive, driving, and Beast Busters. Rev 1 and 2 boot all 4 fighting games, Korean boots the Sam Sho's, driving boots both driving games no matter the region (I have a US and JPN driving I/O) and Beast Busters just boots Beast Busters obv.

The BIOS writes to the Dualport RAM, which seems to configure some hardware level items, but it does so on boot. So the BIOS files are basically the security. But to my knowledge / testing, there is no key or checksum or otherwise the boards are looking for.

So if you really wanted to do a chip swap, so long as the PCB's are the same model (not every Hyper game uses the same PCB...same as MVS/AES) I have not found anything that would prevent it from working.

Granted you would have to find perfect photos of what you wanted to convert TO, as you'd want a chip map as I am not certain all areas are populated in the same manner across games that share the same pcbs.

Have I done this? No. So it's all theoretical, but I can't see anything that would put up a road block security wise.

The I/O was basically SNK's security. Want to convert a driving board to a fighting board? Swap I/O boards and it's done. Takes two minutes. Ive swapped all my I/O boards onto all my motherboards and never had a single issue. So it seems SNK used "hardware security" to lock genres to hardware (I/O pcb) but did NOTHING to secure the games otherwise.
 

awbacon

Mizuki's Demon
Joined
Jan 28, 2009
Posts
3,032
You might be the first person to ever ask this question. Only one way to find out! Socket all of the chips and get burning on those eproms.

You MIGHT run into a clearance issue with sockets. The boards are pretty tightly packed in there. So I'd def measure precisely first before ordering a metric butt load of sockets.
 

Morden

Somewhere in Europe.,
Joined
Jul 5, 2005
Posts
711
You might be the first person to ever ask this question. Only one way to find out! Socket all of the chips and get burning on those eproms.

The only discouraging thing about this undertaking is the amount of smd stuff to be removed and soldered back. It would be a major bummer to go through all that trouble only to have it not work, but I guess you ether pay with your time, or pony up for a Samurai Spirits 64.

Idk if this could potentially help in any way, but I have a spare Hyper cart (I think Buriki) with a destroyed connector. Guessing the guts are intact and you're welcome to it if you want something to pull ROMs from...

I've checked the MAME driver for info, and fortunately, it has an extensive comment section with a lot of useful info. It appears that there are two board revisions, LVS-DG1 and LVS-DG2. DG1 was used for games released in '97, of which there are two. Road's Edge and Samurai Spirits 64. So, it would appear that the only donor cartridge that would be suitable, would be Road's Edge. Scroll characters and sprite roms in DG2 are stored in 64Mbit ROMs, while on DG1, they're 32Mbit.

That broken Buriki cart would be useful only if I messed up, gave up or the whole thing just didn't work. Then, I guess I could salvage one of the connectors from the donor, if only to have SOMETHING that works.

If anyone has a reasonably priced Road's Edge they'd like to get rid of, knowing what will happen to it, I'm here.
 

awbacon

Mizuki's Demon
Joined
Jan 28, 2009
Posts
3,032
The only discouraging thing about this undertaking is the amount of smd stuff to be removed and soldered back. It would be a major bummer to go through all that trouble only to have it not work, but I guess you ether pay with your time, or pony up for a Samurai Spirits 64.



I've checked the MAME driver for info, and fortunately, it has an extensive comment section with a lot of useful info. It appears that there are two board revisions, LVS-DG1 and LVS-DG2. DG1 was used for games released in '97, of which there are two. Road's Edge and Samurai Spirits 64. So, it would appear that the only donor cartridge that would be suitable, would be Road's Edge. Scroll characters and sprite roms in DG2 are stored in 64Mbit ROMs, while on DG1, they're 32Mbit.

That broken Buriki cart would be useful only if I messed up, gave up or the whole thing just didn't work. Then, I guess I could salvage one of the connectors from the donor, if only to have SOMETHING that works.

If anyone has a reasonably priced Road's Edge they'd like to get rid of, knowing what will happen to it, I'm here.

Honestly for the amount of work it would take and no guarantee it would function I’d just watch YAJ auctions and score a decent priced one. I just got lucky on mine and it was basically free since I bought a lot and sold everything that WASNT Sam Sho 64. Kept the marquee too but it’s seen better days.

Fun project If you accomplish it though. Luckily Roads Edge is the way cheaper / easier to find game compared to around Trip RV.

If I decide to sell my driving stuff (cause honestly I don’t think I’ll play them very often) I’ll lyk.
 
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