How do Playstation ROMs work?


I’m confused how Playstation ROMs work. Other systems just have the one file but Playstation seems to have several and in different formats. I’ve tried a .bin file and that worked though RetroArch can’t see the game despite scanning the directory so I have to load content instead.

A different ROM I downloaded has four files, .ccd, .cue, .img and .sub. What are all these? .img appears to be the main file as it’s the biggest. That ROM loaded and does appear in my games list but doesn’t have box art.

I’ve also had a ROM the same as above but the .img file was named .img.ecm. Why? Should I remove the .ecm suffix at the end? This ROM doesn’t load at all. RetroArch says it just fails to load and that’s from load content again because it won’t show up in my games list. The difference between this one and the other one with the four files is the one that works is a European PAL version, the one that doesn’t work is North American NTSC version, in fact none of the NTSC ROMs work.

Then there’s .ISO. I have all my original Playstation discs. Should I convert them all to .ISO? Will those work in RetroArch? Would music tracks still work?

I’m new to RetroArch. Previously I’ve used ePSXe to load Playstation games direct from the CD-ROM but the games run too fast.

What core should I be using? I tried PCSX ReARMed but that doesn’t seem to work at all, in fact when Load Content that core doesn’t even come up as an option so I use Beetle.


The default format for PSX games is .bin, along with a cue file. The bin files are essentially tracks on the disc that the console reads and the cue file tells the system how many there are and in what order to read them. This is the same for emulators such as mednafen/beetle-psx.

Some users convert those bin and cue files into one single image, usually an ISO which many emulators can read such as ePSXE. ecm is similar to ISO but i believe it is more compressed. If you want to clean up your collection and convert all your games into single files, i recommend chd. It is supported by mednafen and it is very small in comparison.

Look here for some discussion on the format: Converting to CHDs for certain cores


If you’re using Windows, ignore PCSX-ReARMed and use Beetle-PSX/-HW instead. The HW core allows you to do fancy resolution increases, etc., while the non-HW version has fewer bugs but is confined to native resolution.

For games, you specifically want bin/cue. ISO files can’t store all of the information needed to make an accurate rip, so it is not recommended (and it doesn’t work with Beetle-PSX/-HW unless you create a cue file to go with it). If you want to make your ROMs smaller, CHD–as Arviel mentioned–is good and compatible, as is PBP/eBoot format, either of which you can convert your ROMs to from bin/cue, so get the bin/cue version first (i.e., dumping your own games with imgburn or whatever).


Thanks! So what’s what the ROMs where some have .IMG and others have .IMG.ECM? I have all the BIOS’s in the System folder but if I load any NTSC ROMs with the four files including .IMG.ECM RetroArch says it failed to load content. Also because I’m having to Load Content rather than pick the game from the games list I don’t know if I should be selecting .ccd or .img. or some other file extension. Can I load a game from a .cue file?

I understand your point about creating my own ROMs as .bin but also creating a. cue file (I found a tool that you drop a .bin file on and it creates the .cue file for you) - however this doesn’t help me with the ROMs I’ve already got which are all .img (or .img.ecm), .sub, cue and .ccd and only the PAL games work and none of the NTSC games do.


ECM is a compression format that I don’t recommend messing with. There is a tool to decompress them, but it’s rarely worth the hassle vs just redumping the ROM in a better format.

IMG formats will usually work, but I think you need to create a cue for them, as well.


Okay. Guess I’ll convert my own discs to .bin and create .cue files for them. Or .iso, I assume .iso includes the .cue file? I’ve only read that .bin files need a .cue file. For any games I don’t have I suppose I’ll have to keep looking, with [edited to remove ROM site name] having removed all it’s ROMs finding a decent site that doesn’t try to get you to download an dodgy .exe instead is pretty difficult.

Also, while something I’ve noticed despite using the PSX HW core I can’t do anything about the graphics. Sure they look they did in the late 90’s but a bit of resolution tweaking would be nice but there doesn’t appear to be any options for that.


Making cue files is easy enough, just simply create a text file ending in .cue and add the game to that from the same directory. Though i would avoid ISO and instead use CHD. One of the many benefits of CHD is that it is more efficient than ISO and it is also very easy to undo the process.


I can’t agree with this more, in fact that posted link was my old topic haha. I do want to mention though that if you do Dreamcast emulation at all to be careful about which version of CHD you are converting to. I did v0.4 or something and ReDream won’t read my files. Reicast still does… but just something to keep an eye on.


Sounds like a plan. I just need to make some time to start converting my discs (and preferably before they begin to deteriorate if they haven’t already).

I also managed to sort out some of those .img.ecm files with the ECM tools. Fairly simple process to uncompress them. I still had issues running some of those downloaded ROMs though until I discovered by BIOS files were in upper case letters when they should be lower case and the USA BIOS had a random dash in it! All sorted now though and working. For my own discs though I’ll do what you say and convert them to CHD.

Can I convert the ROMs I’ve already got from .img, .cue, .bin etc to .CHD?


Yeah, that’s exactly what I always do. I convert any/all CD roms into .bin/.cue, and then if the emu can handle it, I convert them again to CHD.


Awesome! Thanks a lot guys.

Also, still puzzling over how to change the resolution in Beetle PSX HW, is this even possible?


Yeah, once you load a game, go into quick menu > options and look for the resolution option. It has 2x, 4x, 8x, and 16x multipliers.


Img/sub/ccd is clonecd’s format. It’s really good, very accurate rips. And most if not all emulators support it. Loading either the cue file or the ccd will work.


@Squalo is right. CloneCD images are very accurate. You might also come across MDS format, which is what Alcohol 120% used. You probably won’t see too many of these floating around.

I think there still might be some confusion here about all the formats, so let me sum things up.

PSX games, much like other disc-based games can come in several flavours. The image format is usually determined by the software that originally dumped the disc. CDRWin was typically used for .bin/.cue. .iso was generic and pretty much all software supported it. .CCD was CloneCD’s format. .MDS was Alcohol’s format. There were others, like .CDI which you see on Dreamcast games. Those were done by DiscJuggler, typically.

If you’ve downloaded some roms online, you’ve probably run into some with multiple files in bin format. does this with their images. As long as there’s a cue file present, emulators don’t have any issue reading them.

ISO format images can also work, but ISO files can’t contain CD audio tracks, but BIN can. I wouldn’t advise using .ISO for PSX games.

As mentioned above, CCD and .MDS are accurate formats, as they can both retain subchannel data. You can technically also do this with .bin/.cue now, so these two formats aren’t essential.

You’ll also see .PBP. This is the PSP’s PS1 format. This is a compressed format that has the advantage of being able to merge multiple discs into one single file for each game. This makes it easy to switch discs in RetroArch.

Multi-disc games can also be accomplished with other image formats, but this requires a .m3u file. If you’ve used an mp3 player, you’ve seen this file as a playlist. That’s exactly what it does in the case of PSX roms, too, provides a list of discs for the emulator.

Finally, there’s CHD. This is MAME’s “Compressed Hunks of Data” format. Originally used for hard disk images of arcade games, it was expanded to include disc-based games as well. You’ve noticed that most people in this thread prefer this, and there’s a good reason.

First, the compression is excellent. You can get a fair bit of space-saving from the data portion of a PSX game, but CHD’s party-trick is that you also get lossless FLAC compression of the audio tracks as well. Then, it packs everything up in one neat file. It can’t do multi-disc games in one file, but with an M3U file, that’s not a big deal.

I hope this clarified things a bit more.


Thanks for this, it’s very helpful!