mesen-s - RetroBIOS

Type	libretro
Classification	Official ports
Source	https://github.com/libretro/Mesen-S
Upstream	https://github.com/SourMesen/Mesen-S
Version	0.4.0
Profiled	2026-03-24
Cores	mesen-s, mesen_s
Systems	nintendo-snes, nintendo-gb, nintendo-gbc, nintendo-super-game-boy, nintendo-satellaview

Technical notes

High-accuracy SNES/SFC emulator with Game Boy/Color and Super Game Boy support. Upstream archived at 0.4.0, superseded by Mesen2. DSP firmware can be loaded as combined files (dsp1.rom, dsp1b.rom, dsp2.rom, dsp3.rom, dsp4.rom, st010.rom, st011.rom) or split program/data ROMs. Combined files are tried first, size validated. HLE coprocessor option available for DSP-1/DSP-1B only (libretro core option mesen-s_hle_coprocessor). CX4 is fully HLE, no firmware needed. ST018 detected but not emulated. GB/GBC/SGB boot ROMs fall back to embedded open-source SameBoy boot ROMs when external files are not found.

21 files | 0 required, 21 optional | 21 in repo, 0 missing | 8 with HLE fallback

dsp1.program.rom optional in repo HLE fallback

• Size: 6.0 KB
• Validation: size
• Source: Core/NecDsp.cpp:95, Core/FirmwareHelper.h:17-35
• Platforms: lakka, retroarch, retropie, romm
• DSP-1 program ROM. HLE fallback in libretro port only

dsp1.data.rom optional in repo HLE fallback

• Size: 2.0 KB
• Validation: size
• Source: Core/NecDsp.cpp:95, Core/FirmwareHelper.h:17-35
• Platforms: lakka, retroarch, retrodeck, retropie, romm
• DSP-1 data ROM

dsp1b.program.rom optional in repo HLE fallback

• Size: 6.0 KB
• Validation: size
• Source: Core/NecDsp.cpp:96
• Platforms: lakka, retroarch, retrodeck, retropie, romm
• DSP-1B program ROM. HLE fallback in libretro port only

dsp1b.data.rom optional in repo HLE fallback

• Size: 2.0 KB
• Validation: size
• Source: Core/NecDsp.cpp:96
• Platforms: lakka, retroarch, retrodeck, retropie, romm
• DSP-1B data ROM

dsp2.program.rom optional in repo

• Size: 6.0 KB
• Validation: size
• Source: Core/NecDsp.cpp:97
• Platforms: lakka, retroarch, retrodeck, retropie, romm
• DSP-2 program ROM

dsp2.data.rom optional in repo

• Size: 2.0 KB
• Validation: size
• Source: Core/NecDsp.cpp:97
• Platforms: lakka, retroarch, retrodeck, retropie, romm
• DSP-2 data ROM

dsp3.program.rom optional in repo

• Size: 6.0 KB
• Validation: size
• Source: Core/NecDsp.cpp:98
• Platforms: lakka, retroarch, retrodeck, retropie, romm
• DSP-3 program ROM

dsp3.data.rom optional in repo

• Size: 2.0 KB
• Validation: size
• Source: Core/NecDsp.cpp:98
• Platforms: lakka, retroarch, retrodeck, retropie, romm
• DSP-3 data ROM

dsp4.program.rom optional in repo

• Size: 6.0 KB
• Validation: size
• Source: Core/NecDsp.cpp:99
• Platforms: lakka, retroarch, retrodeck, retropie, romm
• DSP-4 program ROM

dsp4.data.rom optional in repo

• Size: 2.0 KB
• Validation: size
• Source: Core/NecDsp.cpp:99
• Platforms: lakka, retroarch, retrodeck, retropie, romm
• DSP-4 data ROM

st010.program.rom optional in repo

• Size: 48.0 KB
• Validation: size
• Source: Core/NecDsp.cpp:100
• Platforms: lakka, retroarch, retrodeck, retropie, romm
• ST-010 program ROM

st010.data.rom optional in repo

• Size: 4.0 KB
• Validation: size
• Source: Core/NecDsp.cpp:100
• Platforms: lakka, retroarch, retrodeck, retropie, romm
• ST-010 data ROM

st011.program.rom optional in repo

• Size: 48.0 KB
• Validation: size
• Source: Core/NecDsp.cpp:101
• Platforms: lakka, retroarch, retrodeck, retropie, romm
• ST-011 program ROM

st011.data.rom optional in repo

• Size: 4.0 KB
• Validation: size
• Source: Core/NecDsp.cpp:101
• Platforms: lakka, retroarch, retrodeck, retropie, romm
• ST-011 data ROM

dmg_boot.bin optional in repo HLE fallback

• Size: 256 B
• Aliases: gb_bios.bin
• Validation: size
• Source: Core/FirmwareHelper.h:148, Core/Gameboy.cpp:108-114, Core/GbBootRom.h:6
• Platforms: lakka, recalbox, retroarch, retropie, romm
• Game Boy (DMG) boot ROM. Falls back to embedded SameBoy open-source boot ROM

cgb_boot.bin optional in repo HLE fallback

• Size: 2.2 KB
• Aliases: gbc_bios.bin
• Validation: size
• Source: Core/FirmwareHelper.h:149, Core/Gameboy.cpp:108-119, Core/GbBootRom.h:6
• Platforms: lakka, recalbox, retroarch, retropie, romm
• Game Boy Color boot ROM. Falls back to embedded SameBoy open-source boot ROM

sgb_boot.bin optional in repo HLE fallback

• Size: 256 B
• Aliases: sgb_bios.bin
• Validation: size
• Source: Core/FirmwareHelper.h:150, Core/Gameboy.cpp:108-127, Core/GbBootRom.h:6
• Platforms: batocera, recalbox, retrobat
• Super Game Boy boot ROM for GB CPU. Falls back to embedded SameBoy open-source boot ROM

sgb2_boot.bin optional in repo HLE fallback

• Size: 256 B
• Aliases: sgb_bios.bin
• Validation: size
• Source: Core/FirmwareHelper.h:151, Core/Gameboy.cpp:108-127, Core/GbBootRom.h:6
• Platforms: batocera, recalbox, retrobat, retrodeck
• Super Game Boy 2 boot ROM for GB CPU. Falls back to embedded SameBoy open-source boot ROM

SGB1.sfc optional in repo

• Size: 256.0 KB
• Validation: size
• Source: Core/FirmwareHelper.h:118-133, Core/BaseCartridge.cpp:630-638
• Platforms: batocera, lakka, recalbox, retroarch, retrobat, retrodeck, retropie, romm
• Super Game Boy SNES cartridge ROM. Without it, SGB mode falls back to regular GB

SGB2.sfc optional in repo

• Size: 512.0 KB
• Validation: size
• Source: Core/FirmwareHelper.h:118-133, Core/BaseCartridge.cpp:630-638
• Platforms: batocera, lakka, recalbox, retroarch, retrobat, retrodeck, retropie, romm
• Super Game Boy 2 SNES cartridge ROM. Core option mesen-s_sgb2 selects SGB version

BS-X.bin optional in repo

• Size: 1.0 MB
• Validation: size
• Source: Core/FirmwareHelper.h:39-47,96-113, Core/BaseCartridge.cpp:65
• Platforms: batocera, lakka, recalbox, retroarch, retrobat, retrodeck, retropie, romm
• Satellaview BS-X BIOS ROM. Minimum accepted size is 32768 bytes

Generated on 2026-04-03T20:37:39Z