Core and Feature Requests

Libretro Cores
#778

I’m not sure if its really needed from my perspective, as the core is based on a core we have in RetroArch already. However I don’t have anything against the idea to add variety. I use Genesis Plus GX as my primary core in RetroArch, which is quiet accurate and should work with 100% of official games. From the official doc: https://mednafen.github.io/documentation/md.html

Mednafen’s Sega Genesis/Megadrive emulation is based off of Genesis Plus and information and code from Genesis Plus GX (old GPL-licensed version). Sega Genesis/Megadrive emulation should still be considered experimental;

We also have PicoDrive as an alternative, which some people prefer and say it should be more accurate. Don’t read old discussions, because it was improved heavily in recent times.

2 Likes
#779

There’s also MAME and FinalBurn Neo for Megadrive/Genesis. Not that I would expect them to substitute the cores that are focused specifically on Sega systems (lack of CD makes this obvious), but who knows? Maybe something that’s problematic isn’t an issue with them.

#780

I heard BlastEm now supports the Sega CD, is that true? The core doesn’t seem to though but i assume it’s an old version?

#781

Looking at the official standalone BlastEm development notes at https://www.retrodev.com/repos/blastem suggest some support for Sega CD. I have no clue to what degree. And the RetroArch core wasn’t updated quite a while: https://github.com/libretro/blastem

#782

You can compile a new BlastEm core from upstream’s source if you want a more up to date core, but Sega CD support hasn’t been added yet to libretro.

I have a Github repo where I upload the source files and use Github Actions to create a build of BlastEm libretro Win64 every once in awhile: https://github.com/Awakened0/blastem-libretro-builds

Edit: Tried to do a fresh build today and got a build error. Reported in their Discord.

1 Like
#783

If you could load the multi-disk games from a zip file, instead of an m3u, it would be very practical.

Interesting, I thought it was only consoles.

This may be an option.

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I was familiar with it, it doesn’t generate much commotion, it would be nice to have it as an alternative (if it were free), but it doesn’t do anything that isn’t already being done.
Something I’m curious about is its “early windows implementation” to run windows games.

#784

From my experience with sonic 3 I would say that I have no problem with MAME Current as a MD/GEnesis emulator, except the some bonus stage scenes that requires lower input lag when the walking speed becomes too high (and Run Ahead nad Preemptive Frames can easily alleviate such situation).

And by doing some input lag tests I found out that MAME-Current has input lag of 3 frames on Sonic 3 (the same as PicoDrive), while Genesis Plus GX has 2 (same as BlastEm).

I would say that Genesis Plus GX might be the most powerful core in the library, the only complaint about it would be the “not so liberal” non-commercial license comparing to GPL. Though that’s really an ideological thing and does not affect personal usage.

1 Like
#785

Im only getting 1 frame of lag with GenesisPlusGX myself.

1 Like
#786

You can get one frame in BlastEm too if you enable Crop Overscan in Settings, Video, Scaling. That doesn’t affect all games, but I remember it removing a lag frame in the Sonics specifically.

1 Like
#787

Recently the PPSSPP emulator and RetroArch core got support for .chd files. I converted all .iso to it and can play the games in .chd format. However the Import Content functionality in RetroArch doesn’t import .chd files. (At the moment I did a simple text replace in the .lpl files, so a rescan is not necessary.)

Just a related sidenote (which could be added to the documentation as well maybe?): psp games should not be converted into regular cd based .chd format. For best performance when converting to .chd, the command chdman createdvd should be used, according the developers of PPSSPP.

1 Like
#788

I have my psp images in .cso, do you think is it worth the conversion from a file size perspective?

1 Like
#789

I just did a test and on three files ~1.5GB I saved ~100MB. So let’s say you have 600 files, the savings would be ~2GB.

Not really worth the trouble for just saving space, but I did read something about RetroAchievements compatibility and CHDs. So I guess there is that to consider.

2 Likes
#790

I was about to do the same test!

well, so I think is not worth the conversion for me, I don’t even have retro achievements enabled :sweat_smile:

But is good to know that chd are now supported.

1 Like
#791

I personally don’t have any .cso files and don’t know how it compares. Given Duimon’s test, it seems to be negligible difference on a modern system. I had them in uncompressed .iso before, so the impact was huge for me converting to .chd. Also converting to this format has other downsides as well, as you cannot tell from file extension alone what system it belongs to. I would have done a convention where every converted file is named like .psp.chd or .neo.chd in example, but then they would not be recognized from the scanners and such anymore.

@Duimon As for the RetroArchivements and CHD support, I don’t use RA anymore too, so cannot test it at the moment. From what I read RA itself supports CHD format. I read someone in LaunchBox forum got PSP games in CHD format working with RetroAchievements. But cannot confirm this myself for RetroArch yet. EDIT: For science I setup my existing RA account again and tested it with two PSP games in CHD format. I get hash error and it won’t work. To make sure the setup works in general, I tested it with a different core (Mesen).

2 Likes
#792

Upstream BlastEm fixed the libretro build problem and I got a new Windows build on my releases page: https://github.com/Awakened0/blastem-libretro-builds/releases

1 Like
#793

What was fixed, the Sega CD support?

It has a different file name so i had to create a new info file for it. Not sure if i did this right, i added chd in the info file but the core still freezes/crashes when i load a Sega CD chd file.

Was there something else fixed?

#794

I know we have VICE for Commodore plus/4 / Commodore 16 but it’s heavily outdated as that part of VICE hasn’t been updated in years. Some newer games don’t run acurately or is not supported at all (Turbo Out Run for instance).

Yape is a much much better emulator and there is an open source version.

Of course, it’s just a suggestion.
3 Likes
#795

Sega CD still isn’t enabled for libretro. I don’t think there’s been any new features added (no core options yet!). But all the latest improvements to the Genesis/MD emulation will be there. You can look through the commits on the mercurial repo to see what the author’s been working on.

I always rename the .dll to blastem_libretro.dll when manually updating so it matches up with the existing info file. One thing to keep in mind when using this updated upstream core is that it uses a different default control mapping than what the RetroArch buildbot core uses.

#796

How come it’s not in the buildbot so it can be updated through the core updater?

#797

Doesn’t the author have to submit it to RA?