Resident Evil Gaiden bug or emulator bug? How can i help to fix it?

[LukasThyWalls]

Hello.

I was testing retroarch with an old game i have, “Resident Evil Gaiden” for GBC, and i ended playing it entirely. But near the end, i found an issue with the game, and i found a reference to it on internet, but not anymore information or if it’s a ROM issue, or the emulator.

When you are almost in the end of the game, you can fight with a upgraded version of recurrent boss (Mutated B.O.W.), but when you are in the fight, and it moves back, the image began to glitch and then the game crash. I recorded it to show exactly what happens https://youtu.be/PEDy0-QAzac .

Used RetroArch (1.9.0, Linux) and Core Gambatte (v0.5.0-netlink) to play the entirely game. Also tested with SRM save and save state in cores Sameboy (1.8.4 35ee9ab) and mGBA (0.8.3 b485ee7), all with the same issue. The ROM i used is “Resident Evil Gaiden (Europe) (En,Fr,De,Es,It).gbc” (MD5: 8a7f483857e251d56a16594ca84d1a7e), also know as “Resident Evil Gaiden (E) (M5) [C][!].gbc”, allegedly reported as a Good Dump. Played in Spanish. Also tested with copied played ROM SRM save with “regaiden.gbc” (cf4d77137f7dd485480d83e33fe76879) with same result, which is a known finishable version https://youtu.be/kiYyjGjlPKo?t=1086 [18:06] but with different setup (VBA-M r1228, No RetroArch).

Searching for answers, i found in the comments section of this site https://retroachievements.org/game/5133 a reference of this is an known issue with the game, but this is the only reference of it i found, but also i see videos of people playing this part without the issue.

Is this really a known problem with this game? Is a dump issue? (Where can i search for know good dump hashes?) Or is it an emulator issue? How can i help to debug this?

I can provide the save files if this can be useful.

Thanks.

[hunterk]

If it’s not working on Sameboy, there’s a very high chance that it’s the game’s fault. It’s extremely accurate.

[LukasThyWalls]

But, if i’m not mistaken, all GB cores shares the ROM saves (at least i can open the ROM with every core and it have the my savegame). I played the entirely game with Gambatte, and when it crashed there, i tried to play that savegame with other cores, included Sameboy. The savegame itself can be the issue or it’s more likely a ROM issue (bad dump?).

I didn’t write before, but other important thing, when the game crash, the savegame doesn’t work anymore, and the game start from the beginning. Hopefully i have a save state and it creates again the savegame.

Today i managed to finish the game avoiding that encounter. Later you encounter again the same monster with the same aspect, but at that moment there is no issue.

Also i can point out, i remember two or three moments when something is not going right, but you can continue the game:

• In a room, the sound of a zombie attacking the character was playing, but there is not zombie around. I ignored it and continued.
• A zombie with an important object disappeared, but when the character left the zone and entered again, it was there and he could take the object.
• At the same moment the character was opening a door, a zombie attacked, but the character crossed the door and the zombie was left behind. The music when a zombie has catch the character was playing for some second meanwhile the character could move freely, until the normal music poped out again.

If it’s a rom issue, like a bad dump, i remember there were webs with databases to compare the hashes of known good dumps or something like that?

[LukasThyWalls]

@hunterk

If it’s not working on Sameboy, there’s a very high chance that it’s the game’s fault. It’s extremely accurate.

I know i saw it somewhere, but there is a site with info about good dumps hashes https://datomatic.no-intro.org/?page=show_record&s=47&n=1010. In fact, i played the game with the trusted dump.

So, can be an issue with the Gambatte core. But i used too the Sameboy core (loading the game save) and it does the same. Maybe the save is corrupted by Gambatte, i don’t know.

Summarizing, knowing where can be the issue, maybe can be fixed in the future.

[LukasThyWalls]

Sorry for revamp this, but i just ended another playthrough (not me really, but i prepared the game and RetroArch to other person), this time using Sameboy Core instead (0.13.6 699dcd7) in RetroArch 1.9.0.

This time the glitch still happened, but not always, and it didn’t clear the savegame like with the other core.

This time i don’t have the save to replay in other cores so… it’s a dead end to this now.

If anyone search about this at least there is some information: If they are facing this issue, they can avoid that monster (with some reloading for sure) and then passthrough the issue because because it only happens there and you can end the game.