emulator: bsnes-mercury
type: libretro
core_classification: enhanced_fork
source: "https://github.com/libretro/bsnes-mercury"
upstream: "https://byuu.org/higan"
profiled_date: "2026-03-23"
core_version: "v094 (Mercury)"
display_name: "Nintendo - SNES / SFC (bsnes-mercury)"
cores: [bsnes_mercury_accuracy, bsnes_mercury_balanced, bsnes_mercury_performance]
systems:
  - nintendo-snes
  - nintendo-sgb
  - nintendo-satellaview
  - nintendo-sufami-turbo

notes: |
  Fork of higan v094 by Alcaro. Restores HLE for coprocessor chips removed
  in v094, adds firmware_appended support and SuperFX overclocking.
  Three profiles: accuracy, balanced, performance (PPU differs, not firmware).
  Core option bsnes_chip_hle (default LLE, requires bsnes_violate_accuracy)
  controls HLE/LLE at runtime. ref: target-libretro/libretro.cpp:428-442

  Firmware loaded from system_dir via file::exists + mmapstream.
  No hash or size validation on any firmware file.
  ref: target-libretro/libretro.cpp:241-263

  firmware_appended: firmware can be appended to end of ROM file.
  ref: ananke/heuristics/super-famicom.hpp:83

  SPC700 IPL ROM (64 bytes) is embedded in the binary.
  ref: target-libretro/libretro.cpp:39

  Upstream higan v094 by byuu (2014, site defunct). Mercury preserves v094
  code with HLE additions documented in changes.diff at repo root.

files:
  # --- NEC uPD7725 DSP chips (DSP1/1B/2/3/4) ---
  # ananke always generates dsp1b filenames for DSP-1 games (backward-compatible)

  - name: dsp1.program.rom
    system: nintendo-snes
    required: false
    size: 6144
    hle_fallback: true
    note: "only loaded via custom BML manifest, ananke uses dsp1b"
    source_ref: "sfc/cartridge/markup.cpp:422-432"

  - name: dsp1.data.rom
    system: nintendo-snes
    required: false
    size: 2048
    hle_fallback: true
    note: "only loaded via custom BML manifest, ananke uses dsp1b"
    source_ref: "sfc/cartridge/markup.cpp:422-432"

  - name: dsp1b.program.rom
    system: nintendo-snes
    required: false
    size: 6144
    hle_fallback: true
    source_ref: "ananke/heuristics/super-famicom.hpp:381"

  - name: dsp1b.data.rom
    system: nintendo-snes
    required: false
    size: 2048
    hle_fallback: true
    source_ref: "ananke/heuristics/super-famicom.hpp:382"

  - name: dsp2.program.rom
    system: nintendo-snes
    required: false
    size: 6144
    hle_fallback: true
    source_ref: "ananke/heuristics/super-famicom.hpp:403"

  - name: dsp2.data.rom
    system: nintendo-snes
    required: false
    size: 2048
    hle_fallback: true
    source_ref: "ananke/heuristics/super-famicom.hpp:404"

  - name: dsp3.program.rom
    system: nintendo-snes
    required: false
    size: 6144
    hle_fallback: true
    source_ref: "ananke/heuristics/super-famicom.hpp:417"

  - name: dsp3.data.rom
    system: nintendo-snes
    required: false
    size: 2048
    hle_fallback: true
    source_ref: "ananke/heuristics/super-famicom.hpp:418"

  - name: dsp4.program.rom
    system: nintendo-snes
    required: false
    size: 6144
    hle_fallback: true
    source_ref: "ananke/heuristics/super-famicom.hpp:431"

  - name: dsp4.data.rom
    system: nintendo-snes
    required: false
    size: 2048
    hle_fallback: true
    source_ref: "ananke/heuristics/super-famicom.hpp:432"

  # --- Hitachi HG51B (CX4) ---

  - name: cx4.data.rom
    system: nintendo-snes
    required: false
    size: 3072
    hle_fallback: true
    source_ref: "ananke/heuristics/super-famicom.hpp:146"

  # --- NEC uPD96050 (ST010, ST011) ---

  - name: st010.program.rom
    system: nintendo-snes
    required: false
    size: 49152
    hle_fallback: true
    source_ref: "ananke/heuristics/super-famicom.hpp:445"

  - name: st010.data.rom
    system: nintendo-snes
    required: false
    size: 4096
    hle_fallback: true
    source_ref: "ananke/heuristics/super-famicom.hpp:446"

  - name: st011.program.rom
    system: nintendo-snes
    required: false
    size: 49152
    source_ref: "ananke/heuristics/super-famicom.hpp:460"

  - name: st011.data.rom
    system: nintendo-snes
    required: false
    size: 4096
    source_ref: "ananke/heuristics/super-famicom.hpp:461"

  # --- ARM DSP (ST018) ---

  - name: st018.program.rom
    system: nintendo-snes
    required: false
    size: 131072
    source_ref: "ananke/heuristics/super-famicom.hpp:475"

  - name: st018.data.rom
    system: nintendo-snes
    required: false
    size: 32768
    source_ref: "ananke/heuristics/super-famicom.hpp:476"

  # --- Super Game Boy ---

  - name: sgb.boot.rom
    system: nintendo-sgb
    required: false
    size: 256
    source_ref: "ananke/heuristics/super-famicom.hpp:133"