I’ve followed every guide out there; I have the chd file in a folder named after the zip, both inside the zip folder and they simply won’t load. Every other mame game works fine…
Edit: So chd games run perfectly fine in mame standalone but not retroarch?
CHDs work in RetroArch.
Do you use the same files as the standalone, with the same folder structure (chd inside it’s folder and the rom outside, both the folder and rom having the same name?)
Do you also use the same MAME version? If either the chd or rom aren’t the same romset version as MAME’s version, there’s a chance of incompatibility. The bigger the gap between the romset and MAME versions, the bigger the chance of the games not working.
Same files, same folder structure, same mame version…
What other files are in the roms folder? I assume in your standalone MAME roms folder you also have all the bios files. Make sure RetroArch can also see those files. Basically, a game may need 3 files to run, the rom, the CHD and the bios.
It could also be a path issue. Standalone MAME has it’s own UI where you double click the game in the list and it works. How are you trying to load those CHDs in RetroArch?
Up to 4 files if it’s a clone romset. While i don’t know of any, there might also be romsets that require several bioses (1 for the main board, 1 for the sound board, …).
@brothanigus logs would probably help
Are you saying that you have the zip inside the same folder as the chd? If so that is incorrect. The chd needs to be in a folder with the zip name but the zip needs to be outside the folder.
I am assuming you are trying to run an arcade chd?
What chd are you trying to run. I will see if I can get it to work.
It would be faster if you could post a log. 
The roms boot in the standalone mame emulator with the exact same folder structure. Retroarch simply will not load CHDs.
How do I get a log?
Edit: Things work fine now. Updated retroach.
I’m having a similar problem. I have area51 folder with area51.chd in it. as well as the small main area51.zip in the main roms folder. my retroarch just immediately shuts down. Works fine in my main MAME. Do I point retroarch to the .chd file itself vs. the main small zip?
I haven’t run any of these for a while, but doesn’t the rom go in the CHD folder along with the individual CHD game folders? I mean to say the rom goes in the folder titled CHD, but not in the game folder (area51 folder, etc). And you launch the game with the rom, not the CHD.
So, I have just tested it and it works. First the file structure setup for the Roms (a slash indicates a directory):
MAME/
|-- area51/
| |-- area51.chd
| |-- area51t.chd
|
|-- area51mx/
| |-- area51mx.chd
|
|-- area51.zip
|-- area51a.zip
|-- area51mx.zip
|-- area51t.zip
|-- area51ta.zip
The game rom area51.zip is in the main MAME roms directory. That directory also contains a sub-directory with the same name as the Rom area51/. That sub-directory contains the CHD files associated with the Rom. To start a game, you run area51.zip as the game.
yup, have it just like that. and it runs fine in mame. Retroarch just insta-closes. There isn’t any like system bios files for chd stuff is there?
Hmm, it works for me, so it does work in RetroArch. The best is to look at the log to see what error messages are output. Either enable the logs in RetroArch, run and close and then look into the log files. Or if you are comfortable with terminal and commandline, just run retroarch --verbose and look what the terminal outputs when you try to play the game. More at https://docs.libretro.com/guides/generating-retroarch-logs .
First you should edit your reply and put the log output into a preformatted box. That can be done by adding 3 ticks before and after the output, like this:
```
line 1
line 2
```
I see you are using Launch Box, which adds additional complexity. Maybe you have to configure there something. Looking at the output, I can see you are using mame2010, but the Rom is located under Arcade64 0.220. Are you sure this Mame version is compatible with the Rom?
RetroArch has newer versions than Mame 2010 available. Maybe you should try different core. Available Arcade cores in MAME are following: https://docs.libretro.com/guides/arcade-getting-started/#quick-tour-of-every-available-core
yeah i ran this from retroarch directory cmd though, outside of launchbox. mame 2010 core has been the only one that ever worked with my romset. And yes, it audits and works from the arcade .220 executable just fine. I’ve spent so many years parring down my set and just recently spent so much time separating vertical roms from horizontal roms, to have core rotation set properly, and be able to have vertical/horizontal playlists. I really don’t want to have to download an entirely new romset. But out of curiosity, which romset are you on that has these chd games working in retroarch?
What is the version of your standalone MAME? I use in RetroArch current MAME, that is automatically updated to standalone current MAME version. However I have pinned it a few versions before so it stays at 0.280. I have a Romset AND CHD files that are specifically made for this specific version of MAME. But CHD files worked since years, I just had to replace them from time to time partially or completely with newer versions of MAME.
So I assume the Rom you try to play isn’t compatible with the RetroArch core you try to play with. Was the log you copied the entire log? It just looks like cutoff, but I’m not sure. You really should edit the reply and put in preformatted box as described. Otherwise its almost unreadable.
yeah that was the entire cmd log window. The romset i have is the one working with arcade .220, i went one by one through my entire collection, and anything that didn’t work in retroarch from this romset, i replaced with a mame 2010 romset i found on internet archive, as well as a few I had to change to fbneo core and roms. I could keep trying to find one that loads in retroarch. But it just seems odd that it loads fine in the arcade .220 mame still. Usually when it doesn’t load in retroarch, it also doesn’t load in mame. But ya never know i suppose.
Standalone MAME 0.220 is from year 2020, while RetroArch MAME2010 is from 2010. There are 10 years development difference in between and it is likely that the particular Rom is not compatible with the older version. RetroArch has multiple MAME cores. Try a newer version of the core.
Edit your log output and put the text in a preformatted text box.
worked with a mame .288 core someone shared on here. So,…damnit…guess I’m updating my entire set. Shouldn’t be that bad actually, since I can use scripts to copy over matching files to my current set.
You should be able to just replace the old set with the new one, and then… I think you said you are using Launchbox… so just run the LB importer. Like 95% of the roms have the same name as they have for a long time, so not much will change except they will work.
Yeah I know that. I mean that I curated my romset files themselves. So there is A LOT of extra files in a full download. I’ll have to compare a list of the files in my directories against a new download and have a script delete the files from the new download that do not match. They are also separated into vertical rom folder as well, so I’ll have to run it for that one as well. Not insurmountable by any means. Just a hassle.