Question regarding Kronos (Saturn) bios startup


I have all the original bios for the Saturn. When I was running the Bettle core, I had the earliest bios startup screen for the system starting. But the startup screen is one I’m not familiar with.

Do I need to do something different with my bios, (naming/placement) in order for the older bios startup screen to be initiated?



Saturn bios startup screens are different between versions. Or am I not understanding your question?


I want the bios intro like this.

What’s weird, is the video is labeled as Europe bios, but I bought my Saturn in North America 1995. But anyway, can Kronos load this bios intro?


Kronos will load whatever bios you give it, you just have to copy it at system/kronos/saturn_bios.bin , there are several fallbacks (it’ll even try to load beetle saturn bioses if present) but that’s the first path it’ll check.


To make sure you have the bios a given core needs, once in game, press F1 and go to Information, which is in the Retroarch’s main menu, then core information, if it’s missing, it will tell you which one(s).


Yeah I know of the core information. It says they’re present which is what’s odd, since the Beetle Saturn core loads the intro I want, and says bios are present. I won’t beven able to check until later tonight, to see what I’m doing wrong.


Translation :

  • it will try to load system/kronos/saturn_bios.bin
  • if not present, it will try to load system/saturn_bios.bin
  • if not present, it will try to load system/sega_101.bin (beetle-saturn JP bios)
  • if not present, it will try to load system/mpr-17933.bin (beetle-saturn US/EU bios)

Basically, what you want to do is copy system/mpr-17933.bin to system/kronos/saturn_bios.bin

NB : beetle-saturn will load one or the other of its 2 bioses depending on the region of the loaded game (not sure why it does that since it’s not mandatory even on original hardware, it might be to avoid resolution changes at runtime since it doesn’t change resolution at all, even for Hi-Res games iirc), kronos will always load the first bios it find (and change resolution every time it’s needed, which is basically between every screen for Hi-Res games).


Thanks for the in depth explanation! I’ll give this a shot tonight.

BTW, I’ve been trying out the nightlies, latest I have is yesterday’s (12-5) I’ve noticed the delay in audio from precious builds is way better now. But I still notice the MMX4 health bar issue and no music in Virtua Cop. Just wanted to know what the nightly builds have been improvements on?



I did exactly as you suggested, it worked! :slight_smile:


I did some improvements on how i deal with games in need of specific cartridge settings, moved the code from the libretro code to the main code, trimmed a lot of it and solved a lot of warnings in the process, loading a game should be twice faster now. I also fixed the audio implementation in the libretro port (now i use something closer to my code in fbalpha, it solves various sync and framerate issues). FCare worked on the GL renderer, fixing various issues, idk the specifics but i saw a lot of issues being closed on the tracker.

Currently i’m working on miscellaneous controller support (gun, mission stick, twin mission stick, wheel, keyboard and mouse), trying to hook them in the libretro port since they exist in the main code, and FCare is working on fixing the GL “core” stuff i started (GPU compatibility should be a lot better after we finish this).


Excellent, keep up the great work! Best Saturn emu I’ve ever used to date! I check the nightlies everyday for this core. And I do notice better loading times too.