Neo Geo CD Conversion Project.

ysselcneogeo

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It's because the Neo Geo CD system only has 1 megabyte of ram for V rom data (sound samples). For most games to fit, you have to trim the game's V rom data to be smaller than 1 megabyte.

Then when the game needs to access any of that sample data that got trimmed off, your speakers get filled with that glitchy mess instead of the intended sound.

The way to fix this would be to program load screens in the middle of the game, but that's too much effort. That's why most conversions are only for the smaller games, that fit within the Neo Geo CD's ram limitations.
Could you use pointers? I know on psp rips I made back in the day where the memory sticks where extremly small you'd just point to smaller files. Example there was a dirt game where the game had different engine sounds for all the cars. I found the smallest sound sample and just made every car only use that sound and removed all the rest of them. Saved a huge amount of room.
 

Neo_Mike_81

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Would be happy if someone could do KOF 01-02, and MOTW for Neo CD, but I dont think the Neo CD could pull it off, or maybe it would be just like the Ports of Neo games on the psone. Did SNK ever try to do KOF 00 for the Neo cd ? Just wondering.
 

Neo Alec

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Would be happy if someone could do KOF 01-02, and MOTW for Neo CD, but I dont think the Neo CD could pull it off, or maybe it would be just like the Ports of Neo games on the psone. Did SNK ever try to do KOF 00 for the Neo cd ? Just wondering.
It's asking an awful lot. To my knowledge, there haven't been any unofficial conversions to NGCD that require mid-game loads.
 

madmanjock

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Would be happy if someone could do KOF 01-02, and MOTW for Neo CD, but I dont think the Neo CD could pull it off, or maybe it would be just like the Ports of Neo games on the psone. Did SNK ever try to do KOF 00 for the Neo cd ? Just wondering.
I remember reading somewhere that MOTW appeared on a release list for the Neo Geo CD but was silently cancelled.

If you look at Last Blade 2 - you can see why they didn't bother doing anymore with the Neo Geo CD. Kinda nice it lasted as long as it did.
 

MidnightPhreak

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Could you use pointers? I know on psp rips I made back in the day where the memory sticks where extremly small you'd just point to smaller files. Example there was a dirt game where the game had different engine sounds for all the cars. I found the smallest sound sample and just made every car only use that sound and removed all the rest of them. Saved a huge amount of room.

So, you would need to decompile the Program roms to even consider using pointers and even then, I think you misunderstand what *pointers are. What you are talking about are Symlinks, where a file on the PSP ISO points to another, not that close to the same thing programatically, unfortunately.

The NeoCD has finite amounts of P,V,C RAM onboard (sorry its been a while since doing any Neo dev stuff, can't give you exact numbers etc), and even then its not as simple as matching an AES/MVS game with similar ROM sizes, because the NeoCD data is broken down into seperate unique (per game) character/stage/music/effect files etc.

Say you try and use KOF98 as a base for a KOF2002 CD port, firstly you would need to break down the individual KOF02 roms into their seperate character/stage/sounds files like the NeoCD expects (Good luck). Even if you could somehow manage that without source, then you would need to modify the character select to point to which character files were chosen (Good Good Luck), and then hope that each of the 3 characters fit into the C ram. if they don't, you would have to edit the C data, inside the broken down character files, and remove specific frames of animation but then you'd change the location of the frames so how do you know what is being loaded, unless you trimmed the existing frames and... And no, unless you have a NeoCD SDK, or Crazy amounts of Time or Intelligence, its basically a fools errand... (And saying this, I would love all Neo games to be available on Neo CD, its just not going to happen).

EDIT: Before you elite hackers come at me asking how the good neocd ports exist then?!!?! Well a lot of the initial NeoCD games, were small enough to basically do a "LOAD ALL GRAPHICS FROM CD" then "LOAD ALL MUSIC SEQ FROM CD" then "LOAD ALL SOUND FX FROM CD", "LOAD PROGRAMMING FROM CD" to the NeoCD's available RAM and then the Neo CD would essentially act like and AES or MVS, they didn't need to access the CD again (all data was in RAM, some games needed the CD for CD AUDIO). Later games like KOF 94/etc, would load data when needed, hence all the loading times and the broken up files rather than loading whole roms. WAH WAH WAH
 
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madmanjock

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I think most people get the Neo Geo CD has limited ram. It’s just non-techies not seeing that a AES/MVS game is not like a cake which you can slice into levels and load one piece at a time on the Neo Geo CD.

If you had the source code of say a PS1 version of a later SNK game with all assets pre-trimmed for a small amount of ram, perhaps that would be more do-able. But why would you bother.
 

Burning Fight!!

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It's just not going to happen, no one is going to reverse engineer a MVS game AND reprogram the game to work with the CD system just so that you can play those games on a Neo CD. What's the incentive? The Neo AES/MVS and Neo CD aren't the only devices that can run these games nowadays, and as far as people are concerned the Neo Geo CD is just a lamer gimped revision of the AES.
 

Burning Fight!!

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Here's a complement to my post: suppose you want to convert a later fighting game to the Neo Geo CD. You have limited graphics RAM to load sprites into. You already know losses will be had considering other late NGCD games and PS1 ports. *IF* you went into all the theoretical trouble of reverse engineering the game and had complete knowledge of the game itself in order to do the conversion, which would take years of your limited time on earth in this hypothetical scenario:

HOW would you choose what animation frames to cut from which characters? HOW would you deal with the fact that the hitboxes would change but not the visuals? Would you leave it as is and have good players whiff moves a lot more? Would you change hitboxes and timing frames and fundamentally change how the game is played?

I hope I successfully illustrated why this is stupid and is never going to happen in easy to understand terms.
 

madmanjock

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Here's a complement to my post: suppose you want to convert a later fighting game to the Neo Geo CD. You have limited graphics RAM to load sprites into. You already know losses will be had considering other late NGCD games and PS1 ports. *IF* you went into all the theoretical trouble of reverse engineering the game and had complete knowledge of the game itself in order to do the conversion, which would take years of your limited time on earth in this hypothetical scenario:

HOW would you choose what animation frames to cut from which characters? HOW would you deal with the fact that the hitboxes would change but not the visuals? Would you leave it as is and have good players whiff moves a lot more? Would you change hitboxes and timing frames and fundamentally change how the game is played?

I hope I successfully illustrated why this is stupid and is never going to happen in easy to understand terms.
I know it’s stupid, but my thinking was use the assets of a PS1 port (or maybe Saturn if it’s not a ram cart game) as your base - the animation frames will already be precut in hopefully a fairly ‘tasteful’ way.

It’s still all kinds of stupid I agree. A fools errand.
 

slugger_dan

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If I was a contractor instead and someone was willing to pay for the effort of porting MOTW to CD, while accepting all the caveats that would come with it, I'd probably do it. Of course the client would be disregarding the dozens of mint MOTW home carts you'd be able to buy for that amount of money and the fact that it'd be compromised, but it would work.

But yeah short of large amounts of money changing hands, it likely isn't happening. People have spent equally stupid amounts of money on sillier things though (remember "DavidG"?) so there's still hope!
 

Burning Fight!!

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If I had a genie that knew 68000 and Z80, I could do it!

no seriously if I actually found a genie I'd waste a wish just for this thread (the other two wishes being permanently healthy and fit, and having a 30cm long member)
 

Neo Alec

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Most of the fan work that has been done porting existing games has amounted to "rom hacking" -- manipulating the binary code, with possibly a little new code when necessary in the really fancy cases. Dissassembling and rewriting the game is a bridge too far. But that's what it would take to port a larger game without the source code.

If I had a genie that knew 68000 and Z80, I could do it!

no seriously if I actually found a genie I'd waste a wish just for this thread (the other two wishes being permanently healthy and fit, and having a 30cm long member)
Don't waste a wish on that when you can wish roms of all the lost/unreleased games into being publicly available.
 

ysselcneogeo

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Most of the fan work that has been done porting existing games has amounted to "rom hacking" -- manipulating the binary code, with possibly a little new code when necessary in the really fancy cases. Dissassembling and rewriting the game is a bridge too far. But that's what it would take to port a larger game without the source code.


Don't waste a wish on that when you can wish roms of all the lost/unreleased games into being publicly available.
I honestly think Metal Slug 4 is the best chance to making a new cd game. Metal slug on the neo is pretty damn solid port. You could go the rom hacking approach and just cut and paste graphics in. The stages are very small on 4. The biggest issue is if you metal slug 1 you can only have 2 character and if you use metal slug 2 you have mid stage loading which you'd have to figure out how to divide the stages of any of the other games into.

Still the way to "port" a game to neo cd would be rom hacking and literally just editing and replacing assets in another game with others.
 

Neo Alec

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I honestly think Metal Slug 4 is the best chance to making a new cd game. Metal slug on the neo is pretty damn solid port. You could go the rom hacking approach and just cut and paste graphics in. The stages are very small on 4. The biggest issue is if you metal slug 1 you can only have 2 character and if you use metal slug 2 you have mid stage loading which you'd have to figure out how to divide the stages of any of the other games into.

Still the way to "port" a game to neo cd would be rom hacking and literally just editing and replacing assets in another game with others.
It's not that simple because the Metal Slug 4 game code would need to be disassembled and split up. What you seem to be talking about is basically pasting MS4 graphics into MS1, which really wouldn't be the same as actually porting MS4.
 

ysselcneogeo

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It's not that simple because the Metal Slug 4 game code would need to be disassembled and split up. What you seem to be talking about is basically pasting MS4 graphics into MS1, which really wouldn't be the same as actually porting MS4.
Yes I obviously know that. Im saying a rom hack is literally the best I could see anyone ever doing. I remember back in the day on nes games using a hex editor and sprite editor just placing visuals in nes games. Its a vastly easier progress than actually trying to port a game over.
 

city41

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Bringing in a small amount of MS4 graphics into MS1 would be tedious but doable, say having Trevor replace Marco. Beyond that it gets hairy really quick. An MS1 in MS4 clothing is probably doable if you have a lot of time on your hands, but the end result would be kinda eh. Using MS1 as the basis of porting MS4 to CD would be a monumental task. For example, MS1 has no auto scrolling levels. Not to mention there's no guarantee the two engines are compatible. I would bet the devs tweaked and changed things as the series progressed.
 

Tarma

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As a massive Neo-Geo CD fan, I am disappointed that SNK didn't see the short comings of the console's design when dealing with the growing MEG count of their games.

That being said, and taking into account some of the feedback and comments I've read in this thread, if, and it is a big if, SNK had the foresight to add an expansion port to either the NGCD or CDZ, would the late Neo-Geo games have worked using a RAM expansion cart a la the Saturn?

For example a 10MB RAM cart would have more than doubled the D-RAM of the console (yes loading would still be a pain but more data could be used).

Thoughts?
 

Burning Fight!!

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They absolutely would, loading would still be a pain? Absolutely, but you wouldn't have KOF scenarios where the action is broken up with loadings every time you switch characters, all of that would be loaded at once, which IMO is the bigger problem with the CD unit. With the CDZ loading stuff at 2x and more RAM for stuff you wouldn't see people whining as much about loading times today, that I can guarantee you.

edit: look at the half full part of the cup, at least they didn't limit what they could do on the MVS/AES system so that the CD units could keep up.
 

Tarma

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They absolutely would, loading would still be a pain? Absolutely, but you wouldn't have KOF scenarios where the action is broken up with loadings every time you switch characters, all of that would be loaded at once, which IMO is the bigger problem with the CD unit. With the CDZ loading stuff at 2x and more RAM for stuff you wouldn't see people whining as much about loading times today, that I can guarantee you.

edit: look at the half full part of the cup, at least they didn't limit what they could do on the MVS/AES system so that the CD units could keep up.
Yeah, apart from KoF '94, I don't play any of the KoF series on NGCD because of the in-fight loading. If you're good at the games, you spend more time waiting for loads than you do fighting, and that's just a step too far for me despite my love of the system.

If they had packed the games with a RAM cart like they did for Saturn it would have been almost perfect (save for the loading). Seeing as SNK pioneered the RAM expansion cart for the Saturn with their KoF '95 port, it's interesting that something similar wasn't implemented into the CDZ.
 
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