0.9.9 / 01-02-2020



Mesen is a high-accuracy NES and Famicom emulator and NSF player for Windows and Linux.



  • High Accuracy: A lot of effort has gone into making Mesen as accurate as possible.

  • High Compatibility: Over 290 mappers supported (all licensed games supported)

  • NES, Famicom, Famicom Disk System, Dendy, VS System, NSF and NSFe emulation is supported.

  • General: Save States, Rewinding, Movie/Audio Recording, Overclocking, Cheat Codes.

  • Video: Numerous video filters, customizable palettes/overscan, support for HDNes' HD packs.

  • Audio: Stereo effects, per-channel volume and panning, equalizer, etc.

  • Misc: Netplay, 7z/zip support, IPS/BPS patch support, automatic updates, and more!





Windows: Vista+ (DirectX 11 / NET Framework 4.5+)

Linux: glibc 2.24+ / Mono 4.2.1+ / SDL 2

WARNING: Save states created with version 0.9.8 (or older) will no longer work in 0.9.9.

New Features

  • Run Ahead: Added run ahead support (in Emulation settings)

  • Emulation: Added 2 new options to emulate known PPU hardware bugs

  • Emulation: Added option to emulate CPU/PPU alignments

  • UI: Added load state and save state menus (with previews and timestamps)

  • Mappers: Added support for Study Box roms (.studybox files)

  • UNROM512/GTROM: Added support for self-flashing

  • Debugger: Various fixes and improvements

  • Event Viewer: Improved filtering options and added the ability to display NTSC borders

Bug Fixes

  • CPU: Rewrote DMC and OAM DMA logic to better match hardware behavior/timings

  • CPU: Fixed an issue with NMIs turning into IRQs (when turning the NMI flag off at the wrong moment)

  • PPU: Fixed PPU OAM fetch pattern on pre-render scanline

  • PPU: Fixed some PPU timings to better match hardware

  • MC-ACC: Improved MC-ACC (licensed MMC3 clone) emulation

  • MMC5: Rewrote a large portion of the code to better match hardware behavior and quirks

  • Mappers: Fixed/improved emulation of a number of mappers used by unlicensed games

  • NSF: Fixed an issue that caused problems with some FDS NSF files

  • Linux: Fixed bug when using nvidia's drivers that caused the screen to be completely black


  • a480c42b28424ffc9517e003b458926d7920e860494103f1e0805e6ad972c08b

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