MiSTer FPGA Forum

I'm really struggling to get Mega CD to run on my Mister. Please help if possible.

Update all placed a "boot.rom" bios in games/MegaCD folder, as well as three others in games/MegaCD/Europe, games/MegaCD/Japan and games/MegaCD/USA respectively.

My USA folder is filled with folders of USA roms, each folder containing that game's .chd file. I switched to chd after bin/cue weren't working, and even switched back on some games for testing.

When I launch the core, It defaults to the US region, presenting a wallpaper of outer space. If I manually select other regions, the wallpaper changes, e.g. "Sonic with Mega Drive 2 logo" for Japan. I've even tried a region specific rom for Europe and Japan in those folders to no avail.

I feel like I've done everything right. Is there a step I'm missing? Does each game need its own BIOS file in the folder? I tried pressing "start" on these wallpaper screens, even after assigning my buttons.

Any help here would be greatly appreciated.

My MegaCD is working well and I've been trying out all sorts of great games I'd not spent a lot of time with like Thunderhawk and Batman Returns.

My working setup looks like this:

/media/fat/games/MegaCD/
Europe/
Japan/
USA/
boot.rom

In each country folder I have a cd_bios.rom
e.g.
/media/fat/games/MegaCD/USA/cd_bios.rom

In each country folder I have the games in folders:
e.g. /media/fat/games/MegaCD/USA/Batman Returns (USA)/
Batman Returns (USA) (Track 01).bin
Batman Returns (USA) (Track 02).bin
...
Batman Returns (USA) (Track 21).bin
Batman Returns (USA).cue

And that's about it. I don't remember doing anything fancy...

Or just use CHD

Try placing a BIOS file in each individual game's folder for ones from different regions.

Instead of multiple bios files, you can as well go with a region-free patched one.

Exactly, Region Free Bios in the the MegaCD folder and use CHD roms. Solved

First off, thanks so much for the responses.

Unfortunately, this is exactly how mine is setup, with CHD files in individual games folders for each region. It must be some issue with my BIOS. But that seems strange since my BIOS were added via the update all script. Are there any tricks for launching a game? also, I tried using other BIOS files but I can't unzip .bin files on my Mac. In the videos I saw, the bios files were all .md. I don't know, I guess I'm doomed to not be able to play Snatcher on my mister!

tidy_cribs wrote: ↑Wed Oct 04, 2023 12:25 am

First off, thanks so much for the responses.

Unfortunately, this is exactly how mine is setup, with CHD files in individual games folders for each region. It must be some issue with my BIOS. But that seems strange since my BIOS were added via the update all script. Are there any tricks for launching a game? also, I tried using other BIOS files but I can't unzip .bin files on my Mac. In the videos I saw, the bios files were all .md. I don't know, I guess I'm doomed to not be able to play Snatcher on my mister!

/games/MegaCD/boot.rom = Should be a valid cd bios, mine has the MD5 hash of 854B9150240A198070150E4566AE1290

Then I put every game in it's own folder. For me I have regional folders:

/games/MegaCD/1 USA/Shining Force CD (USA) (5R, 6R)/

Inside the game within that regional folder I avhe the CHD file:

/games/MegaCD/1 USA/Shining Force CD (USA) (5R, 6R)/Shining Force CD (USA) (5R, 6R).chd

For other regions, like Europe, I use a different BIOS for compatibility, one of the european bioses, and name it cd_bios.rom.

/games/MegaCD/3 Europe/Syndicate (Europe)/cd_bios.rom
/games/MegaCD/3 Europe/Syndicate (Europe/Syndicate (Europe).chd

the MD5 hash of the european bios I use is B10C0A97ABC57B758497D3FAE6AB35A4

You can also put the cd_bios.rom up one level in the "Europe" folder if you want to, and any game in the folders under that will load using that bios for this core.

I just opened a topic about this, I have the same issue as you, but the problem is that I was opening the wrong core.
You need to navigate to /console and choose the last updated core.

I had given up on this. But I just ran update all because I heard the Saturn core was live. I can now run Mega CD core perfectly with no problems! Thanks to everyone in this community. You're incredible!