Rally Chase CD to Cartridge Conversion

[Burning Fight!!]

Yeah, it worked for me without byteswapping it back first. I use romwak from Jeff Kurtz. Just use the /f option.

It seems like it's hitting something in the PLAYER_START routine that doesn't work. I've been referring to freem's documentation here to try to get some insight:

Neo-Geo Assembly Programming for the Absolute Beginner

The cart-to-CD conversion process is documented online, but there is no CD-to-cart that I'm aware of. There's probably something simple I'm just not accounting for. I'll bet folks who have written dev environment's like freem's that automatically output a NGCD version of the rom could find the problem pretty fast.

The game crashes at the end of the demo and during coin-up by calling https://wiki.neogeodev.org/index.php?title=BIOSF_VIDEOEN which is only available in the CD bios (for turning spr/bg display on/off -- weird that they go out of their way to use this if the original game didn't?). Doesn't seem impossible to patch out but not as trivial as running some conversion guide online either.

Would be easier if the MAME debugger didn't piss me off...

 

[Neo Alec]

The game crashes at the end of the demo and during coin-up by calling https://wiki.neogeodev.org/index.php?title=BIOSF_VIDEOEN which is only available in the CD bios (for turning spr/bg display on/off -- weird that they go out of their way to use this if the original game didn't?). Doesn't seem impossible to patch out but not as trivial as running some conversion guide online either.

Would be easier if the MAME debugger didn't piss me off...

Oh crap. Now I see why no one has bothered doing this. If they're using those kinds of functions more than a few times it's probably going to take a lot more work to fix it.

The easiest way to patch out might be just splicing the cart binary code back in in places, if we knew which parts the they are.

 

[Burning Fight!!]

Oh crap. Now I see why no one has bothered doing this. If they're using those kinds of functions more than a few times it's probably going to take a lot more work to fix it.

The easiest way to patch out might be just splicing the cart binary code back in in places, if we knew which parts the they are.

Actually it might be easier than it looks:


ehehe.

 

[Neo Alec]

Okay, now I'm curious what you removed.

My guess is that function is used to make the transition to and from a black screen smoother (if you've ever watched a Neo Geo video in slow motion you've seen how the sprite layers normally don't all draw in at the same time).

 

[Burning Fight!!]

I just NOP'd the call to biosf_videoen (714e714e714e written on 0xA8DE and subsequent bytes on the P1 rom) which is the only time the game calls it.


It's technically playable in mame now although it has that darn wait in between screens for the audio to catch up, and it doesn't play music during the demo. The only thing left to do is to remove the wait for CD hardware (I assume), but there's no way of being 100% sure this will run on real hardware afterwards without actually making a MVS cart for it (or NeoSD? too poor for it )

edit: the file as it is for those who want to play with it: https://anonfiles.com/Ncx1FeY7y0/038_p1_p1

Interesting little tidbit: the game calls itself "Thrash Rally CD" internally, apparently.

 

[Neo Alec]

Nice. This is at least playable, but those waits are bad. I also noticed it has unlimited continues in AES mode.

I wonder if the wait is BIOSF_CDDACMD or something like it.

BIOSF CDDACMD - NeoGeo Development Wiki

wiki.neogeodev.org

 

[Burning Fight!!]

Nice. This is at least playable, but those waits are bad. I also noticed it has unlimited continues in AES mode.

I wonder if the wait is BIOSF_CDDACMD or something like it.

BIOSF CDDACMD - NeoGeo Development Wiki

wiki.neogeodev.org

I think the secret's here: https://wiki.neogeodev.org/index.php?title=CDDA

I'm still not much familiar with how the 68000 communicates with the z80 but it seems like another doable fix. Looks like the main program waits for something the Z80 never writes then the loop times out anticipating CD playback error. I'll look into it.

EDIT: I think the CD version also had unlimited continues so I'm not sure that's something I'd bother changing. MVS mode seems "operable", lol.

 

[Neo Alec]

I can confirm it runs on real hardware. Here's your rom on the NeoSD Pro AES. It works the same as in MAME.

 

[Neo Alec]

I think the secret's here: https://wiki.neogeodev.org/index.php?title=CDDA

I'm still not much familiar with how the 68000 communicates with the z80 but it seems like another doable fix. Looks like the main program waits for something the Z80 never writes then the loop times out anticipating CD playback error. I'll look into it.

EDIT: I think the CD version also had unlimited continues so I'm not sure that's something I'd bother changing. MVS mode seems "operable", lol.

I did check that the byte at $107 was 0. The cartridge music plays. There must be some other crap added causing it to wait.

It's normal for CD games to have unlimited continues, but when porting games like Crossed Swords 2 to AES, it seems AES conventions were respected. I thought there were flag(s) in the header data for this somewhere too.

 

[Burning Fight!!]

I did check that the byte at $107 was 0. The cartridge music plays. There must be some other crap added causing it to wait.

It's normal for CD games to have unlimited continues, but when porting games like Crossed Swords 2 to AES, it seems AES conventions were respected. I thought there were flag(s) in the header data for this somewhere too.

Well I'm not even close to being a Razoola though, I'm just an asshole messing with the ROM
That would be a "nice to have" so I'll have to look at it later.

Meanwhile: I think this is it, can you please test this on real hardware for any crashes/oddities?

038-p1-final.p1 - AnonFiles

anonfiles.com

There was a loop checking $10f6d9 for a non-zero value immediately after calling sound routines, I just blanked out the counter/conditional, which did remove the timing issues for BGM playback but you never know what other function that loop served. If there's no bug, our mission here's complete.

I'll probably upload a proper patch file on romhacking.net later (and definitely make my alternative MVS cart later, too bad about the original MVS cart being expensive nowadays, I wanted to check if link play still exists on my original cart). Thanks for the help!

(btw I'm not going to mess with the C roms because I find the screwed up title screen funny but if you want to see if you can convert the SPR files from the CD to the MVS C roms, that would be nice).

 

[Neo Alec]

Okay, wow nice! I'll give it a try.

Yeah, I'd like to fix the title screen, call this version Rally Chase and put up a .neo for people, etc. I will try, but you obviously deserve all the credit here. The only problem is again, I have trouble following the CD to cart instructions here for the C rom:

1. Read two bytes from your C1
2. Byteswap the bytes from part 1
3. Read two bytes from your C2
4. Byteswap the bytes from part 3
5. Repeat steps 1-4 until your new rom is 4 Megabytes in size
A. Your output file may be smaller if your roms are tiny
6. Save the ouput file as SPR.SPR (Can be different)

 

[Burning Fight!!]

Okay, wow nice! I'll give it a try.

Yeah, I'd like to fix the title screen, call this version Rally Chase and put up a .neo for people, etc. I will try, but you obviously deserve all the credit here. The only problem is again, I have trouble following the CD to cart instructions here for the C rom:

1. Read two bytes from your C1
2. Byteswap the bytes from part 1
3. Read two bytes from your C2
4. Byteswap the bytes from part 3
5. Repeat steps 1-4 until your new rom is 4 Megabytes in size
A. Your output file may be smaller if your roms are tiny
6. Save the ouput file as SPR.SPR (Can be different)

I think romwak can do it, maybe using "Split File Two, Alternating Words (/w)" then on each split file do /f. It's worth a try.

 

[Neo Alec]

I loaded up your final version of the rom on real hardware. I played through the entirety of both modes with manual transmission on MVS difficulty and it went without a hitch. You nailed it!

I think romwak can do it, maybe using "Split File Two, Alternating Words (/w)" then on each split file do /f. It's worth a try.

Thanks. I will look at the C roms later on tonight.

 

[wyo]

I really need to hook up 4 player Thrash Rally some time.

 

[Neo Alec]

I got it. I didn't have to do any of that romwak stuff you mentioned because NGFX GraphicsEditor allows you to open cart or CD C roms and then save them as cart or CD. It was actually two C roms that needed to be replaced. Here they are for your downloading convenience:

(See first post for files.)



At first I only had the first C rom replaced and that looks like this:

 

[Tarma]

When's the limited run AES release coming out from Basement Soft?

 

[Takumaji]

That's impressive, guys. Trash Rally is great, love the game.

However, I think Neo Driftout is the slightly better game overall.

 

[AppleiDog]

When's the limited run AES release coming out from Basement Soft?

Aliexpress

 

[Neo Alec]

When's the limited run AES release coming out from Basement Soft?

Fucking never.

How about Burning Fight Soft? He did everything.

 

[Burning Fight!!]

I got it. I didn't have to do any of that romwak stuff you mentioned because NGFX GraphicsEditor allows you to open cart or CD C roms and then save them as cart or CD. It was actually two C roms that needed to be replaced. Here they are for your downloading convenience:

038-c1.c1

drive.google.com

038-c2.c2

drive.google.com

View attachment 63103

At first I only had the first C rom replaced and that looks like this:

View attachment 63104

Great job!

It's good that you actually went and did it because the corrupted title screen got old surprisingly fast

 

[Burning Fight!!]

Fucking never.

How about Burning Fight Soft? He did everything.

I'm only doing a hyper ultra rare limited run of 1 mvs cartridge for me to play. Maybe wait for the french (ng.com is 2000% _______ ...) or the chinese on aliexpress, though I suspect really only me and Alec care about playing Thrash Rally

 

[Neo Alec]

I also wanted future generations to know they are playing the CD exclusive Rally Chase on cart systems, rather than the mysterious hack, Rally Thras.

I'm only doing a hyper ultra rare limited run of 1 mvs cartridge for me to play. Maybe wait for the french (ng.com is 2000% _______ ...) or the chinese on aliexpress, though I suspect really only me and Alec care about playing Thrash Rally

I'm really interested to see how your cart works. I guess I had assumed link play wouldn't work, just like how they removed the option from the menus for Riding Hero and League Bowling, but you're right that it might work.

 

[Burning Fight!!]

I also wanted future generations to know they are playing the CD exclusive Rally Chase on cart systems, rather than the mysterious hack, Rally Thras.


I'm really interested to see how your cart works. I guess I had assumed link play wouldn't work, just like how they removed the option from the menus for Riding Hero and League Bowling, but you're right that it might work.

It's like a 50/50 chance of the link function being intact or not. Problem is:

1. not emulatable
2. no dump of link microcontroller
3. actual thrash rally cartridges aren't cheap for a while now

No chance of me trying it out

 

[Neo Alec]

It's like a 50/50 chance of the link function being intact or not. Problem is:

1. not emulatable
2. no dump of link microcontroller
3. actual thrash rally cartridges aren't cheap for a while now

No chance of me trying it out

Oh sorry, I missed that part when I first read your post. Sounds like you're making a cart without the link function.

Another reason why link cable functionality on the NeoSD would have been great.

 

[Tarma]

Fucking never.

How about Burning Fight Soft? He did everything.

You guys should team-up: Burning Basement Games

Has a certain ring to it, no?

Start pre-orders now, buy yourself a nice holiday in a month, ship in five years. Sounds like a winner to me.