Features
- Added support for Sega CD / Mega CD emulation
- Supports all of the same configuration options as Genesis / Mega Drive
- Currently only the CUE/BIN file format is supported, but both single-BIN and one-BIN-per-track are supported
- A BIOS with a matching region is required for Sega CD / Mega CD games to boot
- The JP Model 1 BIOS (V1.00) currently does not work for unknown reasons, but every other major BIOS version should work including the JP Model 2 BIOS (V2.00)
- Added an option to remove the 16/20-sprite-per-scanline and 256/320-sprite-pixel-per-scanline limits for Genesis and Sega CD
- Added 4 different horizontal blur shaders
- Horizontal blur 2px: Linearly interpolates each pair of horizontally adjacent pixels with 1-1 weights
- Horizontal blur 3px: Linearly interpolates each triple of horizontally adjacent pixels with 1-2-1 weights
- Conservative anti-dither: Blends triples of horizontally adjacent pixels that look like dithering, with conservative detection heuristics
- Aggressive anti-dither: Blends triples of horizontally adjacent pixels that look like dithering, with more aggressive detection heuristics
- Added a scanline shader which can be configured to either Dim (50% color on a linear scale) or Black
- Added an option to emulate the Genesis VDP's non-linear color DAC, which tends to brighten darker colors and darken brighter colors (in other words, all colors except pure black and pure white are pushed towards gray)
- Added an option to quantize YM2612 FM channel outputs from 14 bits to 9 bits, which is enabled by default; this reduces dynamic range at low volumes but is more accurate to original hardware, which multiplexes the channels through a 9-bit DAC
- Added several additional audio configuration options
- Added a new option for audio gain in decibels, which increases (positive gain) or decreases (negative gain) overall audio volume
- Device queue size, internal buffer size, and audio sync threshold are now configurable
- They were previously hardcoded to 64, 64, and 4096 respectively, and the device queue size of 64 in particular could cause audio skipping in some environments; device queue size now defaults to 512, and audio sync threshold now defaults to 8192
- Added a pause/unpause hotkey (default P) that completely halts the emulator until it is pressed again
- GUI now supports multiple ROM directories
Fixes
- Added a high-pass filter to Genesis audio output, which fixes some games outputting a low-volume high-pitched noise at times when they're supposed to be silent (e.g. Streets of Rage 3 during the SEGA splash screen)
- Tweaked Genesis VINT timing, which mostly fixes the music tempo in Earthworm Jim
- Fixed a 68000 CPU bug where DIVS and DIVU were setting the Z flag based on the combined quotient+remainder instead of only the quotient; this was discovered while testing Batman Returns (Sega CD)
- Fixed a Genesis VDP bug where no sprites would render if a game placed the sprite attribute table at the highest possible address in VRAM; this was discovered while testing Snatcher (Sega CD)