[Sepp666]

Hello all,

does anyone know why the Konami GB Collection Vol.4 does not run on the GBA with a ez-flash card? I like to play Castlevania II Belmont's revenge in color, but no way - only a black screen on the GBA.

Kind regards Sepp

[Jorpho]

To be clear, are you talking about an EZ-Flash Jr? Can you run other GBC games?

[Chronosplit]

If you're talking about a GBA flashcart, look up the emulator and see if it has compatibility with the game first.  The GBA carts only run GB/GBC games through Goomba Color.

If it's a GBC flashcart like the junior, I'm pretty sure those don't require you to do anything with it and work similarly to the Everdrive GB line.

[Sepp666]

OK, sorry for the missing Info here... I have it on the Ez-Flash Omega. Other GBC Games that I have tested are running good so far. I tried to convert the Konami GB Collection Vol.4 with Goomba color, but it doesn't start also... So i have the same problem with the Collection Vol.2, while Vol.1+3 are running great. To check if the roms have an error i loaded them into VisualBoyAdvance on my PC and they are running great. So i have no clue what's going on here. Is there a way to extract each of the 4 games of that package to run them stand allone? I wish i could extract Castlevania II color. I saw that there is a hack that let you directly boot into Castlevania II without loading up the menu where to select which game you want to play of the 4 and i have tested it but it doesn't work too. :-(

[Jorpho]

That is a much more informative post, thank you.

A little Googling suggests you are not the first person to have this problem.
https://www.dwedit.org/dwedit_board/viewtopic.php?id=639
https://krikzz.com/forum/index.php?topic=5780.15

No idea what we can do about it, though.

To check if the roms have an error i loaded them into VisualBoyAdvance on my PC and they are running great.

To be clear, are those the GBC ROMs, or the roms converted with Goomba Color?

Is there a way to extract each of the 4 games of that package to run them stand allone?

I dimly recall from the last time this came up that there is no easy way to do it.  Whichever game is at the start of the ROM might be easy to extract, but the addresses in each of the other games would all need to be re-written.  But don't take my word for it.

ETA: There is A Clue! on the second page of Google results.
http://nintendo-ds.dcemu.co.uk/newsarchive/03-2008.html

fixed: STOP opcode (fixes Konami Collection 2 JP & 4 JP)

This seems to suggest the problem here is a flaw in Goomba Color's emulation.  The question now is if it would be easier to fix Goomba Color or to find some way to patch the opcode out of the ROM (without breaking it completely).

[Sepp666]

Thank you for searching for a way to help me Jorpho! OK, so it is a problem with the .rom and the emulation... I think that I need help from a experienced person to solve the problem as my knowledge of hacking roms is zero... Anybody here that has the skill to look for it, or help me with this? Jorpho?

[Jorpho]

Oh, it's well beyond my capabilities.  I'd need a lot more time than I have these days if I was going to puzzle it out.

I note that https://rgbds.gbdev.io/docs/v0.4.1/gbz80.7#STOP says that the STOP instruction is "used to switch between double and normal speed CPU modes in GBC", so it makes sense that you would find it uniquely employed in a compilation of older Game Boy games.

To eliminate the obvious: are you using the latest version of Goomba Color from https://www.dwedit.org/gba/goombacolor.php , released last year?  I expect a lot of sites wouldn't have that update.

[Sepp666]

Jorpho, the Goomba color is part of the Ez-Flash Omega card that I use with my Gameboy advance... As I checked I am on the newest software from Ez-Flash. It's Kernel 1.07 and Fw 7.in that software it should be the latest version of Goomba color. I thought that there would be less people that have much free time to have a look at it. Maybe dACE will show up on this thread here, he did something with the Konami Collection vol.4 maybe he knows what to do... But hope is not very good because he last logged in here last year...

[Jorpho]

There appears to already be some discussion on https://www.dwedit.org/dwedit_board/viewtopic.php?id=728 about using a "custom kernel" to get updated versions of Goomba Color.

[EvilJagaGenius]

I have the latest version of Goomba Color installed via Sterophonick's Simple kernel found here: https://gbatemp.net/threads/new-theme-for-ez-flash-omega.520665/

Unfortunately, the Konami GB Collections 2 and 4 don't boot there either.  However, the Konami GB Collection games are GB compatible, so I used a different version of Goomba - I think it was Kuwanger's Goomba Paletted - and all 4 ROMs run fine in there in GB mode.  You'll have to give up color, but you'll be able to play the games.

Alternatively, the four Japanese Konami GB Collections run fine with Super Game Boy color and borders, but have the disadvantage of being in Japanese.  Pick your poison.

[Jorpho]

Okay, that answers that question, thank you.

The next obvious suggestion is: perhaps you could try making a post on Dwedit's board, considering the author still seems interested in making changes to Goomba Color?  (It would be useful to say that Lameboy had similar problems, and that those problems were due to handling of the STOP opcode, and that the STOP opcode might be uniquely used in this case to switch the GBC CPU to normal speed.)

[Sepp666]

Thank you Jorpho and Jaga for your input here and the searching for a solution. I will try to contact Dwedit. Maybe he can help us. Kind regards Sepp