emulator: Mednafen STV
type: libretro
core_classification: community_fork
source: "https://github.com/beudbeud/libretro-stv"
upstream: "https://mednafen.github.io/"
profiled_date: "2026-10-17"
source_commit: "2e42ef0c5d8238c170bcf182e68951c214fc6867"
core_version: "v1.2.1"
display_name: "Sega - ST-V (Mednafen STV)"
cores:
  - "mednafen_stv"
systems:
  - "sega-stv"
  - "sega-saturn"

notes: |
  Libretro core by beudbeud built on the Saturn/ST-V module of Mednafen
  1.32.1, with an Asia ST-V BIOS setting and a stvbios.zip fallback added
  to ss.cpp. Recalbox runs it for ST-V; the loader also accepts Saturn
  disc images (cue, toc, ccd, chd, m3u).

  retro_init() points filesys.path_firmware at the frontend system
  directory and names the BIOS of every region
  (ref: libretro/libretro.cpp:615-641). The ST-V BIOS is picked by SMPC
  area: Japan, Asia NTSC, Europe PAL, and North America for every other
  area (ref: mednafen/ss/ss.cpp:1436-1446, mednafen/ss/smpc.h:32-40).
  A Saturn disc takes sega_101.bin for Japan and Asia NTSC and
  mpr-17933.bin otherwise (ref: mednafen/ss/ss.cpp:1447-1453).

  The loose file is tried first and must be exactly 524288 bytes; when it
  is missing or the wrong size, the same name is looked up at the root of
  stvbios.zip in the system directory, then without the leading slash
  (ref: mednafen/ss/ss.cpp:1455-1491). With ss.bios_sanity on, the
  default, a file named like one of the five Saturn BIOS images must
  match its SHA-256; the ST-V images are not in that table and only the
  size check applies (ref: mednafen/ss/ss.cpp:1493-1540, 2549).

  Saturn games that need the KoF 95 or Ultraman ROM cartridge, and the
  Action Replay 4M Plus cart type, open their ROM from the firmware
  directory under the default names below
  (ref: mednafen/ss/ss.cpp:1348-1350, 1404-1412, 2542-2544).

files:
  - name: "epr-20091.ic8"
    system: "sega-stv"
    region: [japan]
    required: true
    size: 524288
    validation: [size]
    description: "ST-V BIOS (Japan)"
    source_ref: "libretro/libretro.cpp:636, mednafen/ss/ss.cpp:1438-1439, 1462-1468"
  - name: "epr-19854.ic8"
    system: "sega-stv"
    region: [asia-ntsc]
    required: true
    size: 524288
    validation: [size]
    description: "ST-V BIOS (Asia/Taiwan)"
    source_ref: "libretro/libretro.cpp:637, mednafen/ss/ss.cpp:1440-1441, 1462-1468"
  - name: "epr-17952a.ic8"
    system: "sega-stv"
    region: [north-america, latin-america, brazil, south-korea, asia-pal]
    required: true
    size: 524288
    validation: [size]
    description: "ST-V BIOS (North America)"
    source_ref: "libretro/libretro.cpp:638, mednafen/ss/ss.cpp:1444-1445, 1462-1468"
    note: "Used for every SMPC area other than Japan, Asia NTSC and Europe PAL."
  - name: "epr-17954a.ic8"
    system: "sega-stv"
    region: [europe]
    required: true
    size: 524288
    validation: [size]
    description: "ST-V BIOS (Europe)"
    source_ref: "libretro/libretro.cpp:639, mednafen/ss/ss.cpp:1442-1443, 1462-1468"
  - name: "stvbios.zip"
    system: "sega-stv"
    category: bios_zip
    required: false
    description: "ST-V BIOS archive"
    source_ref: "mednafen/ss/ss.cpp:1472-1491"
    note: "Read only when the loose BIOS file is missing or not 524288 bytes. The member is found by the BIOS file name; its size is not checked."
    contents:
      - name: "epr-20091.ic8"
      - name: "epr-19854.ic8"
      - name: "epr-17952a.ic8"
      - name: "epr-17954a.ic8"
  - name: "sega_101.bin"
    system: "sega-saturn"
    region: [japan, asia-ntsc]
    required: true
    size: 524288
    sha256: "dcfef4b99605f872b6c3b6d05c045385cdea3d1b702906a0ed930df7bcb7deac"
    validation: [size, sha256]
    description: "Saturn BIOS (Japan)"
    source_ref: "libretro/libretro.cpp:640, mednafen/ss/ss.cpp:1449-1450, 1507, 1520-1521"
  - name: "mpr-17933.bin"
    system: "sega-saturn"
    region: [north-america, latin-america, brazil, south-korea, asia-pal, europe]
    required: true
    size: 524288
    sha256: "96e106f740ab448cf89f0dd49dfbac7fe5391cb6bd6e14ad5e3061c13330266f"
    validation: [size, sha256]
    description: "Saturn BIOS (North America/Europe)"
    source_ref: "libretro/libretro.cpp:641, mednafen/ss/ss.cpp:1451-1452, 1509, 1520-1521"
  - name: "mpr-18811-mx.ic1"
    system: "sega-saturn"
    required: false
    description: "The King of Fighters '95 ROM cartridge"
    source_ref: "mednafen/ss/ss.cpp:1348, 1404-1412, 2542"
    note: "Opened only for the game that needs the cart; that game does not start without it."
  - name: "mpr-19367-mx.ic1"
    system: "sega-saturn"
    required: false
    description: "Ultraman ROM cartridge"
    source_ref: "mednafen/ss/ss.cpp:1349, 1404-1412, 2543"
    note: "Opened only for the game that needs the cart; that game does not start without it."
  - name: "satar4mp.bin"
    system: "sega-saturn"
    required: false
    description: "Action Replay 4M Plus firmware"
    source_ref: "mednafen/ss/ss.cpp:1350, 1404-1412, 2544"
    note: "Opened only when the Action Replay 4M Plus cart type is selected."