Neo Geo CD Conversion Project.

werejag

Galford's Poppy Trainer
Joined
May 3, 2005
Posts
2,626
bits of this guide are not explained

like in the prg.prg booting part why are these 14 bytes changed and are they the same for all prg.prg files for aLL games?
 

Razoola

Divine Hand of the UniBIOS,
Staff member
Joined
Nov 12, 2002
Posts
4,632
werejag said:
bits of this guide are not explained

like in the prg.prg booting part why are these 14 bytes changed and are they the same for all prg.prg files for aLL games?

Those bytes are changed because the offset tables in the normal neogeo bios and CD bios are different so the program ROM is patched to point to the new offsets. I don't quite understand why that progcnv program doesn't do this for you. Looking at that webpage though (the one with instructions on) its clear that either there is a bug in the progcnv program or its text output is incorrect

From the screenshot I can see it says 'swap bytes at 0x66 and 0x6a'. This is wrong, you need to swap longwords at 0x64 and 0x68 (0x00112233 0x44556677 becomes 0x44556677 0x00112233).

Raz
 

Sly DC

Bashful Neophyte
Joined
Aug 9, 2006
Posts
10
I didn't programmed the PROGCNV.exe tool, the programmer nick is "iq_132" and
i'm pretty sure that he doesn't know that you need to byteswap 0x66 to 0x69 with 0x6A to 0x6D. KaNyErO told me about the byteswap (and now Razoola confirms it) but KaNyErO told me it was only for some specific games like Eightman but it works with the two swapped bytes (0x66 with 0x6A)....weird huh ?!

But now since Razoola confirms that we need to byteswap 0x66 to 0x69 with 0x6A to 0x6D, i will specify it on the web site and do all the new ports with this info (Thanks very much Razoola!! :) )

--- Sly DC ---

P.S. to Razoola: Will you ever make a release of the Unibios for the NGCD ?? I would be in heaven if ever you do!! :)
 

Neo Alec

,
20 Year Member
Joined
Dec 7, 2000
Posts
9,266
Sly DC said:
P.S. to Razoola: Will you ever make a release of the Unibios for the NGCD ?? I would be in heaven if ever you do!! :)
A better project would be a bios for the Hyper Neo 64 that makes the gun and racing games boot on the fighting board. Maybe there's just one byte of data that locks it out.
 

cdoty

Neo Bubble Buster
Joined
Feb 18, 2005
Posts
47
Sly DC said:
i'm pretty sure that he doesn't know that you need to byteswap 0x66 to 0x69 with 0x6A to 0x6D. KaNyErO told me about the byteswap (and now Razoola confirms it) but KaNyErO told me it was only for some specific games like Eightman but it works with the two swapped bytes (0x66 with 0x6A)....weird huh ?!

You need to:
Byteswap PRG rom, append banks together.

Swap the IRQs at 0x64 and 0x68 (DWORD values). This swaps the VBlank and HBlank IRQs.

And change locations:
0x40 - 00 C0 05 22 00 C0 05 28 00 C0 05 2E 00 C0 05 34
0x50 - 00 C0 05 3A 00 C0 04 F2 00 C0 04 EC 00 C0 04 E6
0x60 - 00 C0 E0 00


It's cool to see someone finally figured this out. And my versions do have incorrect colors, this was pointed out by Chirs Covell.

I guess in my excitement of getting it working, I didn't check the colors. The sprite banks probably need to be byte swapped.
 
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NeoLord

Neo-Geo FAQs Editor
Joined
Aug 26, 2000
Posts
2,429
I was really excited when I read this thread, but when I clicked on the 'link' provided in his initial post, it comes up with this:

For Sale

Internet Domain Name

www.Game-Shoppe.com

For The Current Price

CLICK HERE



What's going on?
 
E

Electric Head

Guest
Sorry, need help

I'm sorry I'm posting this here (where it doesn't belong) but I have no other choice!

I am new and I ca't open new threads, just answer in some forums, like this "News And Rumors" one.

Anyone knows why?

Thanks!
 

Whitesnake

Timid Neo Newbie
Joined
May 2, 2010
Posts
8
Are there any people still interested in resurrecting this project? With a fresh guide and new set of tools? :)
 

wyndcrosser

Baseball Star Hitter
Joined
Apr 24, 2012
Posts
1,268
kuk thanks. still looking for shock troopers and nightmare in the dark. thanks
 

Coligion

Neo Bubble Buster
Joined
Sep 9, 2007
Posts
44
Did anyone attempt to convert Flip Shot? That one is small enough that it should work (46 Megs). I always thought it was a pretty decent two-player game; it was not as good as Windjammers, but still fun.
 

Neo Alec

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20 Year Member
Joined
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Posts
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Did anyone attempt to convert Flip Shot? That one is small enough that it should work (46 Megs). I always thought it was a pretty decent two-player game; it was not as good as Windjammers, but still fun.
Without checking, I think the graphics or sound roms were too big.
 

kuk

Benimaru's Hairdresser
Joined
Feb 13, 2005
Posts
791
the probleme is the limitation of 4 Mo for the Graphism, you could have more but you should delete and load the new graphism (and have a loading time)
 

Whitesnake

Timid Neo Newbie
Joined
May 2, 2010
Posts
8
Thanks for the link kuk.

I was hoping maybe people in the know would have the tools to appropriately scale down certain game assets for the NGCD.

Rather than just chopping the files.

Like King Of The Monsters, extracting the audio data and maybe checking for unused data or using techniques to shorten the audio data. So it would fit in the 1mb rather than what we have now. ;)
 

mikew

Krauser's Shoe Shiner
Joined
Mar 28, 2012
Posts
243
Like King Of The Monsters, extracting the audio data and maybe checking for unused data or using techniques to shorten the audio data. So it would fit in the 1mb rather than what we have now. ;)

The NGCD has 2MB available for PCM data, not 1MB :)
 

Pedrobear

Cheng's Errand Boy
Joined
Mar 1, 2012
Posts
113
The NGCD has 2MB available for PCM data, not 1MB :)

Watbird.jpg
 

kuk

Benimaru's Hairdresser
Joined
Feb 13, 2005
Posts
791
well for me it's 1 Mo or 7 Mbits
7 Mb no more, no less. 7 shall be the number thou shalt count, and the number of the counting shall be 7. 8 shalt thou not count, neither count thou 6, excepting that thou then proceed to 7. 9 is right out. Once the number 7, being the 7 number, be reached, then lobbest thou
Amen
 

mikew

Krauser's Shoe Shiner
Joined
Mar 28, 2012
Posts
243
The NGCD has 2MB available for PCM data, not 1MB :)

**CORRECTION**

I want to apologize for misleading you guys here. You were correct, the NGCD does indeed only have 1MB of PCM ram. For awhile I was thinking there was 2MB but after running many tests to confirm, only 1MB of PCM ram is useable. It's setup as 2 banks of 512KB however if you are doing CD conversions it probably doesn't make any difference as you would be loading all of the data from one entry starting at 0x0 in the IPL.TXT.
 

Burning Fight!!

Jaguar Ninja
Joined
Jan 12, 2014
Posts
2,019
Bump!

I was testing Eight Man and it's sad that it has some missing sfx that glitch out into an annoying beep. I was wondering if I could hack the Z80 program to ignore playback of out-of-memory samples... but for that I'd have to know an emulator that lets me set breakpoints on the REG_SOUND port in the z80 side, and let me step through code. Anyone has any recommendations? I could work in the weekend on this project.

EDIT: Seems like Mame has an OK debugger and Neo-Geo CD(Z) support, but I need to brush up on the z80 neo docs first.

EDIT 2: I have disassembled a bit of the Z80 code but it seems like it's not gonna be easy to do my original plan in a straightforward way. Seems like 68000 commands get translated in some odd way with a table on $4C4C, which does not correspond to actual track code numbers (like the Unibios jukebox codes). I changed ONE entry to 00 and that was enough to wreck havoc in the music side of the game to hilarious results.

I'll see if I can go deeper into the driver (Makoto 2.0A) and figure out how it works but it seems to me it might be too much effort for little payoff. Dunno if I should give up yet.
 
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amobile

Timid Neo Newbie
Joined
Nov 17, 2016
Posts
4
Bump!

I was testing Eight Man and it's sad that it has some missing sfx that glitch out into an annoying beep. I was wondering if I could hack the Z80 program to ignore playback of out-of-memory samples... but for that I'd have to know an emulator that lets me set breakpoints on the REG_SOUND port in the z80 side, and let me step through code. Anyone has any recommendations? I could work in the weekend on this project.

EDIT: Seems like Mame has an OK debugger and Neo-Geo CD(Z) support, but I need to brush up on the z80 neo docs first.

EDIT 2: I have disassembled a bit of the Z80 code but it seems like it's not gonna be easy to do my original plan in a straightforward way. Seems like 68000 commands get translated in some odd way with a table on $4C4C, which does not correspond to actual track code numbers (like the Unibios jukebox codes). I changed ONE entry to 00 and that was enough to wreck havoc in the music side of the game to hilarious results.

I'll see if I can go deeper into the driver (Makoto 2.0A) and figure out how it works but it seems to me it might be too much effort for little payoff. Dunno if I should give up yet.

HI Burning Fight ( ;) i love your nickname !)

I didn't understand everything you said, i'm not a programmer, but could you explain to me with simple words ;) why almost all the conversion games got this horrible sound bug ?
I'm making a small video of presentation of the conversions we can find on neogeo CD, and i would like to avoid nonsenses on it ;)
On my neoCD with NeoCD SDLoader, only Ando Dunos, Puzzle de Pon + Puzzle de Pon R and Pop 'N Bounce didn't have the sound issue (Pop 'N Bounce got others bugs but it's not the subject here ;) )...
I precise that i pickup the iso on the Kuk's website http://neogeocdworld.info/html/jeux/jeux/conversions.html
Maybe it exists earlier version of these converts somewhere else on the web ?

Thanks for your lights :)
 
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Neo Alec

,
20 Year Member
Joined
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Posts
9,266
HI Burning Fight ( ;) i love your nickname !)

I didn't understand everything you said, i'm not a programmer, but could you explain to me with simple words ;) why almost all the conversion games got this horrible sound bug ?
I'm making a small video of presentation of the conversions we can find on neogeo CD, and i would like to avoid nonsenses on it ;)
On my neoCD with NeoCD SDLoader, only Ando Dunos, Puzzle de Pon + Puzzle de Pon R and Pop 'N Bounce didn't have the sound issue (Pop 'N Bounce got others bugs but it's not the subject here ;) )...
I precise that i pickup the iso on the Kuk's website http://neogeocdworld.info/html/jeux/jeux/conversions.html
Maybe it exists earlier version of these converts somewhere else on the web ?

Thanks for your lights :)
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.
 
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