Ymir

This is a nightly release built from the latest commit. Before you use these builds, make sure to backup your data, especially the save states!

Save states are constantly evolving and are only guaranteed to be compatible on stable (numbered) releases. The file format may be changed without notice, so be careful when using save states from nightly releases.

You can find the changelog for this build here.

[!NOTE] Nightly builds include experimental and in-development features that may not work properly. When reporting issues, make sure to include the version number (Help > About > Copy version).

[!IMPORTANT] It is recommended to install the latest GPU drivers in order to use Direct3D or Vulkan:

• Nvidia: Find your GPU here or use the Nvidia App to update drivers automatically
• AMD: Find your GPU or CPU here or use the download buttons at the top to update drivers automatically
• Intel: Find your GPU or CPU here

Windows users: install the latest Microsoft Visual C++ Redistributable package (x86_64 installer, AArch64/ARM64 installer) before running the emulator. This is mandatory to avoid crashes on startup.

macOS users: follow these instructions to allow Ymir to run on your system. Ymir is signed with an ad-hoc certificate, flagging it as unverified.

Linux users: if you choose to install the Flatpak version, make sure to grant Ymir permission to access the filesystem or your disc images won't load properly.

Ymir v0.4.0

Discord | Patreon | Compatibility list | Screenshots

SDL Renderer has been the backbone of graphics on Ymir... until now. Ymir now supports Direct3D 12 and Metal (with Vulkan to come in the future), which will enable implementation of shaders and resolution scaling down the line. Direct3D 12 also supports hardware-accelerated VDP rendering, offloading heavy graphics computations to your GPU for a significant performance boost with no accuracy compromises -- it's as accurate as the software renderer, save for undiscovered bugs. Other graphics backends will eventually support acceleration as well, hang tight!

The Virtua Gun has been promoted to a stable feature after numerous bug fixes and accuracy improvements that made it work flawlessly with most supported games. Known issues are listed in #787: only one game doesn't register shots, and three don't recognize reloads consistently.

Good news for old Mac owners: Ymir should now run on macOS 12 (Monterey)! The macOS build configuration was targeting the default version, which happened to be 15 for a while until GitHub decided to upgrade their build runners and push the default to 26. This prompted us to look into those builds and lower the minimum version to 12, which is the lowest supported version by the current runner.

Finally, as you've come to expect, every big release comes with dozens of polish passes, crash and bug fixes, accuracy improvements, performance boosts, and better compatibility. Ymir 0.4.0 is now compatible with 94.4% of the entire Saturn library, and can run up to 10% faster with SCSP threading compared to 0.3.3, or even more if you enable GPU-accelerated VDP1/VDP2 rendering.

[!IMPORTANT] Windows users: install the latest Microsoft Visual C++ Redistributable package (x86_64 installer, AArch64/ARM64 installer) before running the emulator. This is mandatory to avoid crashes on startup.

macOS users: follow these instructions to allow Ymir to run on your system. Ymir is signed with an ad-hoc certificate, flagging it as unverified.

Linux users: if you choose to install the Flatpak version or installed Ymir from the SteamOS's Discover Store, make sure to grant Ymir permission to access the filesystem or your multi-file disc images won't load properly.

It is recommended to install the latest GPU drivers in order to use Direct3D or Vulkan:

• Nvidia: Find your GPU here or use the Nvidia App to update drivers automatically
• AMD: Find your GPU or CPU here or use the download buttons at the top to update drivers automatically
• Intel: Find your GPU or CPU here

Do not use Windows Device Manager or Windows Update to update your GPU drivers, as they tend to have poor performance and lack support for advanced GPU features.

Always update your integrated GPU driver first, even if you're not using it. This also applies to desktop PCs with dedicated graphics cards.

Compatibility improvements

Here's a small showcase of games that now work on v0.4.0 or had major bugs fixed:

<img width="3681" height="3888" alt="image" src="https://github.com/user-attachments/assets/9629dad2-4f3d-4543-bf79-3a3a9

Ymir v0.3.3

Discord | Patreon | Compatibility list | Screenshots

This is a small maintenance release that fixes a regression with Akumajou Dracula X (#904), improves autodetection of the Asia NTSC region (Korea and Taiwan), adds some missing theme colors introduced in recent ImGui updates, and corrects some documentation oversights. It also implements the VDP2 color gradation effect, fixing the background in Saturn Bomberman's Egg Birdon boss fight.

Check the meatier v0.3.2 release notes for details on what's included in this version.

[!IMPORTANT] Windows users: install the latest Microsoft Visual C++ Redistributable package (x86_64 installer, AArch64/ARM64 installer) before running the emulator. This is mandatory to avoid crashes on startup.

macOS users: follow these instructions to allow Ymir to run on your system. Ymir is signed with an ad-hoc certificate, flagging it as unverified.

Linux users: if you choose to install the Flatpak version or installed Ymir from the SteamOS's Discover Store, make sure to grant Ymir permission to access the filesystem or your multi-file disc images won't load properly.

VDP2 color gradation

The only notable improvement in this version is the implementation of the VDP2 color gradation effect, which can be seen in the Egg Birdon boss arena of Saturn Bomberman:

Here's a video captured from hardware with a RetroTink 4K of the same scene. Ymir's output perfectly matches what the Saturn produces.

Changes

New features and improvements

• GUI: Specify missing ImGui style colors.
• System: Add Europe PAL and Asia NTSC (in that order) to default preferred regions after North America and Japan.
• VDP2: Implemented color gradation effect. Fixes background in the Egg Birdon boss arena of Saturn Bomberman.

Fixes

• System: Properly autoselect IPL ROMs for Asia NTSC region (South Korea, Taiwan).
• VDP1: Don't automatically mark jumps to 0 as infinite loops. Fixes Akumajou Dracula X no longer booting. (#904)

Which version should I download?

Grab the file matching your operating system and processor architecture:

• windows, linux and macos indicate the operating system
• x86_64 is for Intel or AMD CPUs and AArch64/ARM64 is for ARM CPUs
• All builds are for 64-bit systems

For x86_64 builds, the AVX2 version offers slightly better performance but requires a CPU that supports the instruction set -- pretty much any Intel Core or AMD CPU since 2011 and Intel Pentium/Celeron CPUs from 2020 onwards has support for it. If you don't know if AVX2 is supported or you have no idea what any of this means, it's probably safe to grab the AVX2 version if you don't have an ancient or cheap computer. If it doesn't start up or randomly crashes for no reason, try the SSE2 version.

Every ARM build also includes support for the NEON instruction set.

For Windows releases, you might also need to install the latest Microsoft Visual C++ Redistributable package ([x86_64 installer](https://aka.ms/vs/17/release/vc_red

Ymir v0.3.2

Discord | Patreon | Compatibility list | Screenshots

This release brings a large set of bug fixes and accuracy improvements once again guided by @celeriyacon's test ROMs, pushing compatibility to just over 94%! A workaround for 16 games described below would bring this number to 94.6%.

The highlight of this version is the huge set of fixes to CD Block HLE, bringing more parity with the LLE counterpart and improving compatibility and stability with dozens of games. VDP1 fixes also resolved a few longstanding issues and brought some games to life.

Performance got another huge boost in multiple avenues with this version. First, thanks to @SternXD, you can now offload audio processing tasks to another CPU core, freeing up the emulator thread to focus more heavily on the SH-2s and general system logic. This alone can boost performance by up to 25% and possibly more, depending on how much work is put on the SCSP DSP.

SH-2 emulation got faster and more accurate by properly emulating the CPU's fetch stage which pulls two instructions in a single fetch, approximately halving the number of expensive memory accesses done by the interpreter. Alongside that, there have been a number of performance microoptimizations to various aspects of SH-2 emulation that combine into another 10-15% boost to emulation of CPU-heavy games. Grandia's FMVs are notoriously intensive, and this set of improvements marks the first time I've seen it run at over 200 fps on my system.

Of course, with every release there's also room for more features. The SH-2 CPUs can now be overclocked up to 500% to reduce lag in poorly-optimized games, or underclocked down to 25% to lower host CPU usage on lighter games. As everything in the Saturn tends to be timing-sensitive, this comes with a disclaimer that it might break games, but it works well in most cases.

There's now support for Japanese characters (visible in the Backup Memory Manager and other places), a number of debugger improvements and new features, new options to hide the game title and performance indicators from the window title bar, an option to pause emulation upon startup, and a few more odds and ends.

[!IMPORTANT] Windows users: install the latest Microsoft Visual C++ Redistributable package (x86_64 installer, AArch64/ARM64 installer) before running the emulator. This is mandatory to avoid crashes on startup.

macOS users: follow these instructions to allow Ymir to run on your system. Ymir is signed with an ad-hoc certificate, flagging it as unverified.

Linux users: if you choose to install the Flatpak version or installed Ymir from the SteamOS's Discover Store, make sure to grant Ymir permission to access the filesystem or your multi-file disc images won't load properly.

Compatibility improvements

Here's a small showcase of games that now work on v0.3.2 or had major bugs fixed:

(click any image to zoom)

With v0.3.2, Ymir's compatibility has pushed ahead of Kronos and is just over 94%.

<img width="1446" height="362" alt="image" src="https://github.com/user-attachments/assets/71c0