Ymir Version 0.3.1

Ymir v0.3.1, a Sega Saturn emulator, introduces features like loading games from various file formats, automatic BIOS ROM detection, and customizable keybindings. It supports up to two players, backup RAM management, and offers save states, rewinding, turbo speed, and a debugger for enhanced gameplay. Performance optimizations have been made in the software renderer, particularly for high-resolution games. The update also includes various fixes, such as addressing audio track shifts and improving graphics rendering in specific games. Key technical improvements streamline rendering processes and reduce unnecessary computations. Ymir v0.3.1 is available for download.

(HEY YOU!! We hope you enjoy! We try not to run ads. So basically, this is a very expensive hobby running this site. Please consider joining us for updates, forums, and more. Network w/ us to make some cash or friends while retro gaming, and you can win some free retro games for posting. Okay, carry on 👍)

Ymir v0.3.1 has been launched. It’s an ongoing development of a Sega Saturn emulator.

Key Features:
Load games from BIN+CUE, IMG+CCD, MDF+MDS, or ISO formats.
Automatic detection of IPL (BIOS) ROM.
Automatic region switching.
Support for up to two players with standard Control Pads on both ports (more to follow).
Completely customizable keybindings.
Support for backup RAM and DRAM cartridges (more features to come).
Integrated memory manager for importing and exporting saves, and transferring between internal and cartridge RAM.
Save states.
Rewind functionality (up to one minute at 60 fps), turbo speed, and frame stepping (forwards and backwards).
A feature-rich debugger still in development.

Ymir Changelog:
New features and enhancements:
Debugger: Added Priority Stack to VDP2 debug overlay.
VDP2: Several performance optimizations in the software renderer, boosting performance in graphics-intensive games (particularly in high resolution modes). Technical details:
RBG1 rendered unnecessarily when NBG0 was enabled and RBG1 was turned off.
Removed redundant transparency bit as priority zero acts as transparency.
Eliminated various unused function arguments to reduce CPU register and stack pressure.
Passed VDP2 register references as arguments instead of fetching them repeatedly.
Reused line data (i.e., skipped recomputing lines) for vertical mosaic rendering.
Packed character pattern data into a single 32-bit value.
Microoptimized calculations for scroll coordinates.
Specialized rotation parameter table calculations for no coefficient table, per-line coefficient table, and per-dot coefficient table.
Lifted coefficient table enable checks out of the loop.
Made inner loops SIMD-friendly.
Avoided unnecessary calculations of transparency and line color screen data if they are disabled.
Microoptimizations for the compositor function:
Layer sorting now utilizes a combined key.
Gathered layer data in one single loop.
Pixel fetching now uses templates with some early bail-out checks.
The color offset calculation enable flag is cleared in the fetch loop when no offset is applied.
Fixes:
Debugger: Various fixes for SH2 stack analysis.
Game DB: Added slow VDP1 flag to Funky Fantasy to improve slow FMVs.
Media: Identified postgaps in data tracks when the CUE sheet doesn’t explicitly mention them, fixing audio track shifts in faulty Virtua Fighter 2 dumps.
Media: Resolved PREGAP/POSTGAP handling in CUE/BIN dumps, correcting shifted audio tracks in games dumped with ImgBurn.
SH2: Fixed handling of illegal slot instruction exceptions (thanks to @celeriyacon).
VDP1: Introduced a game-specific flag to skip command processing if the top of the table is empty, enabled exclusively for Sekai no Shasou kara – I Swiss-hen – Alps Tozantetsudou no Tabi, fixing missing graphics in Gungriffon. (#810)
VDP1: Disabled early polygon drawing termination when rendering polygons with inverted user clipping mode, resolving clipped polygons around the minimap in Machine Head (#767).
VDP1: Implemented simple infinite loop detection, fixing slowdown in the Mojave Desert stage (1-2) in Gale Racer.
VDP2: Applied color calculations to the transparent sprite mesh on layer 0, fixing stripes on the ground plane in Gungriffon.
VDP2: Separated color offset application to transparent sprite mesh on layer 0, solving the missing spotlight in the Colonel battle in Mega Man X4. (#818)
VDP2: Corrected VRAM access calculations when RBG1 is enabled, repairing missing car graphics in Gale Racer. (#359)
VDP2: Fixed and utilized line color screen calculation ratio when LNCL is inserted, resolving text background issues in Doukoku Soshite. (#502)