diff --git a/emulators/ep128emu.yml b/emulators/ep128emu.yml
new file mode 100644
index 00000000..a62c9f30
--- /dev/null
+++ b/emulators/ep128emu.yml
@@ -0,0 +1,309 @@
+emulator: ep128emu-core
+type: libretro
+source: "https://github.com/libretro/ep128emu-core"
+cores:
+  - ep128emu_core
+systems:
+  - enterprise-64
+  - enterprise-128
+  - videoton-tvc
+  - amstrad-cpc
+  - zx-spectrum
+
+# ep128emu-core emulates Enterprise 64/128, Videoton TVC, Amstrad CPC 464/664/6128,
+# and ZX Spectrum 48/128. All ROMs are optional because the core ships built-in
+# fallback ROMs compiled into roms.hpp. External ROM files override the built-ins
+# and provide better accuracy for some systems.
+#
+# ROM path: <system_dir>/ep128emu/roms/
+#
+# Machine selection (core/core.cpp:62-118):
+#   Content file extension determines machine type:
+#   .cas/.tap/.bas/.128/.com/.trn -> Enterprise
+#   .tvcwav/.cas(TVC) -> Videoton TVC
+#   .cdt/.tzx -> Amstrad CPC or ZX Spectrum (autodetect)
+#   .img/.dsk -> Enterprise disk (default) or CPC/TVC depending on content
+#
+# Enterprise ROM layout (core/core.cpp:195-307):
+#   EP128 (default): exos21.rom (segments 0-1) + basic21.rom (segment 4/5)
+#   EP64: exos20.rom (segments 0-1) + basic20.rom (segment 4/5)
+#   EP128 enhanced: exos24uk.rom (segments 0-3, 64K)
+#   Disk mode: exdos13.rom (segments 0x20-0x21)
+#   IS-DOS mode: exdos14isdos10uk.rom (segments 0x20-0x21)
+#   File I/O mode: epfileio.rom (segment 0x10)
+#   DTF mode: zt19uk.rom (segments 0x40-0x41)
+#   Hungarian locale: hun.rom + epdos16f.rom
+#   German locale: brd.rom
+#
+# Built-in fallbacks (roms/roms.hpp:46516-46538):
+#   All 22 ROMs have compiled-in defaults. The core prepends "_default_" to
+#   the filename and looks up the builtin_rom map when no external file is found.
+#   This means the core works out of the box without any user-supplied ROMs.
+#
+# TOSEC alternate names (core/core.hpp:80-118):
+#   The core tries TOSEC naming conventions as fallback before using built-in ROMs.
+#   For example exos21.rom -> "Expandible OS v2.1 (1985)(Intelligent Software).bin"
+#   CPC ROMs can also be split into page-sized files (OS.ROM + BASIC.ROM).
+
+notes: |
+  All ROMs go under <system_dir>/ep128emu/roms/. The core has built-in ROM
+  fallbacks for every file, so it works without any user-supplied ROMs.
+  External ROMs provide byte-exact originals vs the built-in copies.
+
+  Enterprise EP128 is the default machine. EP64 is selected when content
+  requires it. Machine type can also be forced via core options.
+
+  Hungarian and German locale ROMs are loaded automatically when content
+  metadata indicates the locale. The IS-DOS disk system is an alternative
+  to the standard EXDOS disk controller.
+
+files:
+  # ============================================================
+  # Enterprise 64/128 - EXOS (Expandible OS)
+  # ============================================================
+
+  - name: exos21.rom
+    path: ep128emu/roms/exos21.rom
+    md5: f36f24cbb87745fbd2714e4df881db09
+    required: false
+    system: enterprise-128
+    has_builtin: true
+    note: "Enterprise 128 EXOS 2.1. Default OS for EP128 machines."
+    source_ref: "core/core.cpp:234-237"
+
+  - name: exos20.rom
+    path: ep128emu/roms/exos20.rom
+    md5: 5ad3baaad3b5156d6b60b34229a676fb
+    required: false
+    system: enterprise-64
+    has_builtin: true
+    note: "Enterprise 64 EXOS 2.0. Used when EP64 machine type is selected."
+    source_ref: "core/core.cpp:226-229"
+
+  - name: exos24uk.rom
+    path: ep128emu/roms/exos24uk.rom
+    md5: 55af78f877a21ca45eb2df68a74fcc60
+    required: false
+    system: enterprise-128
+    has_builtin: true
+    note: "Enterprise 128 EXOS 2.4 (UK). Used when enhanced ROM mode is enabled. 64K, loaded across segments 0-3."
+    source_ref: "core/core.cpp:214-221"
+
+  # ============================================================
+  # Enterprise 64/128 - BASIC interpreter
+  # ============================================================
+
+  - name: basic21.rom
+    path: ep128emu/roms/basic21.rom
+    md5: e972fe42b398c9ff1d93ff014786aec6
+    required: false
+    system: enterprise-128
+    has_builtin: true
+    note: "Enterprise 128 BASIC 2.1. Loaded when cartridge mode is active (default)."
+    source_ref: "core/core.cpp:248,276"
+
+  - name: basic20.rom
+    path: ep128emu/roms/basic20.rom
+    md5: 8e18edce4a7acb2c33cc0ab18f988482
+    required: false
+    system: enterprise-64
+    has_builtin: true
+    note: "Enterprise 64 BASIC 2.0. Used with EP64 machine type."
+    source_ref: "core/core.cpp:246,264,274"
+
+  # ============================================================
+  # Enterprise 64/128 - disk controllers
+  # ============================================================
+
+  - name: exdos13.rom
+    path: ep128emu/roms/exdos13.rom
+    md5: ddff70c014d1958dc75378b6c9aab6f8
+    required: false
+    system: enterprise-128
+    has_builtin: true
+    note: "EXDOS 1.3 disk controller. Loaded for EP128_DISK and EP64_DISK modes. 32K across segments 0x20-0x21."
+    source_ref: "core/core.cpp:303-306"
+
+  - name: exdos14isdos10uk.rom
+    path: ep128emu/roms/exdos14isdos10uk.rom
+    required: false
+    system: enterprise-128
+    has_builtin: true
+    note: "EXDOS 1.4 + IS-DOS 1.0 (UK). Used for IS-DOS disk mode instead of exdos13.rom."
+    source_ref: "core/core.cpp:295-298"
+
+  # ============================================================
+  # Enterprise 64/128 - file I/O and extensions
+  # ============================================================
+
+  - name: epfileio.rom
+    path: ep128emu/roms/epfileio.rom
+    md5: a68ebcbc73a4d2178d755b7755bf18fe
+    required: false
+    system: enterprise-128
+    has_builtin: true
+    bundled: true
+    note: "Direct file I/O extension. Loaded for EP128_FILE and EP64_FILE modes. Source included in roms/ directory."
+    source_ref: "core/core.cpp:283-284"
+
+  - name: zt19uk.rom
+    path: ep128emu/roms/zt19uk.rom
+    md5: 228540b6be83ae2acd7569c8ff0f91d0
+    required: false
+    system: enterprise-128
+    has_builtin: true
+    note: "ZozoTools 1.9 (UK). Loaded for DTF (direct tape file) mode. 32K across segments 0x40-0x41."
+    source_ref: "core/core.cpp:287-290"
+
+  # ============================================================
+  # Enterprise 64/128 - locale extensions
+  # ============================================================
+
+  - name: hun.rom
+    path: ep128emu/roms/hun.rom
+    md5: 22167938f142c222f40992839aa21a06
+    required: false
+    system: enterprise-128
+    has_builtin: true
+    note: "Hungarian language extension. Auto-loaded when content locale is Hungarian."
+    source_ref: "core/core.cpp:242-243"
+
+  - name: epdos16f.rom
+    path: ep128emu/roms/epdos16f.rom
+    required: false
+    system: enterprise-128
+    has_builtin: true
+    note: "EP-DOS 1.6f. Provides HFONT and CLKOFF for Hungarian locale. 32K across segments 0x06-0x07."
+    source_ref: "core/core.cpp:252-255"
+
+  - name: brd.rom
+    path: ep128emu/roms/brd.rom
+    md5: 6af0402906944fd134004b85097c8524
+    required: false
+    system: enterprise-128
+    has_builtin: true
+    note: "German (BRD) language extension. Auto-loaded when content locale is German."
+    source_ref: "core/core.cpp:260-261"
+
+  # ============================================================
+  # Enterprise 64/128 - optional extras (in .info, not in source)
+  # ============================================================
+
+  - name: epd19hft.rom
+    path: ep128emu/roms/epd19hft.rom
+    md5: 12cfc9c7e48c8a16c2e09edbd926d467
+    required: false
+    system: enterprise-128
+    note: "EP-DOS 1.9 with Hungarian font. Listed in .info file as optional firmware."
+    source_ref: "ep128emu_core_libretro.info:firmware8"
+
+  - name: zt19hfnt.rom
+    path: ep128emu/roms/zt19hfnt.rom
+    md5: 653daaf7b9b29c2c4e577f489580f247
+    required: false
+    system: enterprise-128
+    note: "ZozoTools 1.9 with Hungarian font. Listed in .info file as optional firmware."
+    source_ref: "ep128emu_core_libretro.info:firmware9"
+
+  # ============================================================
+  # Videoton TVC
+  # ============================================================
+
+  - name: tvc22_sys.rom
+    path: ep128emu/roms/tvc22_sys.rom
+    md5: 8c54285f541930cde766069942bad0f2
+    required: false
+    system: videoton-tvc
+    has_builtin: true
+    note: "TVC system ROM v2.2. Main BIOS for all TVC modes."
+    source_ref: "core/core.cpp:313-314"
+
+  - name: tvc22_ext.rom
+    path: ep128emu/roms/tvc22_ext.rom
+    md5: 5ce95a26ceed5bec73995d83568da9cf
+    required: false
+    system: videoton-tvc
+    has_builtin: true
+    note: "TVC extension ROM v2.2. Loaded alongside tvc22_sys.rom."
+    source_ref: "core/core.cpp:315-316"
+
+  - name: tvcfileio.rom
+    path: ep128emu/roms/tvcfileio.rom
+    md5: a2cf86ba8e7fc58b242137fe59036832
+    required: false
+    system: videoton-tvc
+    has_builtin: true
+    bundled: true
+    note: "TVC direct file I/O extension. Used for TVC64_FILE mode. Source included in roms/ directory."
+    source_ref: "core/core.cpp:319-320"
+
+  - name: tvc_dos12d.rom
+    path: ep128emu/roms/tvc_dos12d.rom
+    md5: 88dc7876d584f90e4106f91444ab23b7
+    required: false
+    system: videoton-tvc
+    has_builtin: true
+    note: "TVC DOS 1.2d. Loaded for TVC64_DISK mode."
+    source_ref: "core/core.cpp:324-325"
+
+  # ============================================================
+  # Amstrad CPC
+  # ============================================================
+
+  - name: cpc464.rom
+    path: ep128emu/roms/cpc464.rom
+    md5: a993f85b88ac4350cf4d41554e87fe4f
+    required: false
+    system: amstrad-cpc
+    has_builtin: true
+    note: "CPC 464 combined ROM (OS + BASIC). 32K loaded at segments 0x10 (OS) and 0x00 (BASIC) with offset."
+    source_ref: "core/core.cpp:335-338"
+
+  - name: cpc664.rom
+    path: ep128emu/roms/cpc664.rom
+    md5: 5a384a2310f472c7857888371c00ed66
+    required: false
+    system: amstrad-cpc
+    has_builtin: true
+    note: "CPC 664 combined ROM (OS + BASIC). Used for CPC_664_DISK mode."
+    source_ref: "core/core.cpp:343-346"
+
+  - name: cpc6128.rom
+    path: ep128emu/roms/cpc6128.rom
+    md5: b96280dc6c95a48857b4b8eb931533ae
+    required: false
+    system: amstrad-cpc
+    has_builtin: true
+    note: "CPC 6128 combined ROM (OS + BASIC). Default CPC machine when no specific model requested."
+    source_ref: "core/core.cpp:352-355"
+
+  - name: cpc_amsdos.rom
+    path: ep128emu/roms/cpc_amsdos.rom
+    md5: 25629dfe870d097469c217b95fdc1c95
+    required: false
+    system: amstrad-cpc
+    has_builtin: true
+    note: "AMSDOS disk controller ROM. Loaded for CPC_DISK and CPC_664_DISK modes."
+    source_ref: "core/core.cpp:359-360"
+
+  # ============================================================
+  # ZX Spectrum
+  # ============================================================
+
+  - name: zx128.rom
+    path: ep128emu/roms/zx128.rom
+    md5: 85fede415f4294cc777517d7eada482e
+    required: false
+    system: zx-spectrum
+    has_builtin: true
+    note: "ZX Spectrum 128K ROM. 32K loaded at segments 0x00-0x01."
+    source_ref: "core/core.cpp:382-385"
+
+  - name: zx48.rom
+    path: ep128emu/roms/zx48.rom
+    md5: 4c42a2f075212361c3117015b107ff68
+    required: false
+    system: zx-spectrum
+    has_builtin: true
+    note: "ZX Spectrum 48K ROM. Used for ZX16 and ZX48 modes."
+    source_ref: "core/core.cpp:389-390"
diff --git a/emulators/freechaf.yml b/emulators/freechaf.yml
new file mode 100644
index 00000000..1092dd14
--- /dev/null
+++ b/emulators/freechaf.yml
@@ -0,0 +1,81 @@
+emulator: FreeChaF
+type: libretro
+source: "https://github.com/libretro/FreeChaF"
+cores:
+  - freechaf
+systems:
+  - fairchild-channelf
+
+notes: |
+  FreeChaF is a Fairchild Channel F emulator ported to libretro.
+
+  BIOS loading is in src/libretro.c:186-208. The core first tries to load
+  sl90025.bin (Channel F II PSU1) at address 0x000. If that fails, it falls
+  back to sl31253.bin (original Channel F PSU1) at the same address. PSU2
+  (sl31254.bin) is always loaded at address 0x400.
+
+  Memory layout from src/memory.h:27-30:
+    0x000-0x3FF  PSU1 ROM (sl31253 or sl90025)
+    0x400-0x7FF  PSU2 ROM (sl31254)
+    0x800-0x1FFF cartridge ROM
+    0x2000+      VRAM
+
+  If either PSU ROM fails to load, the core switches to experimental HLE
+  (high-level emulation) for that PSU. A warning message is shown to the
+  user recommending real BIOS files. HLE state is tracked per-PSU via
+  hle_state.psu1_hle and hle_state.psu2_hle (src/channelf_hle.c).
+
+  The .info file declares all three firmware files as required (opt=false),
+  but the core does not abort on missing BIOS -- it falls back to HLE.
+
+files:
+  - name: "sl31253.bin"
+    system: fairchild-channelf
+    required: false
+    md5: ac9804d4c0e9d07e33472e3726ed15c3
+    size: 1024  # 1 KB, fills 0x000-0x3FF
+    note: "Channel F PSU1 ROM (original). Fallback if sl90025.bin is missing."
+    source_ref: "src/libretro.c:192"
+
+  - name: "sl31254.bin"
+    system: fairchild-channelf
+    required: false
+    md5: da98f4bb3242ab80d76629021bb27585
+    size: 1024  # 1 KB, fills 0x400-0x7FF
+    note: "Channel F PSU2 ROM. Always loaded at address 0x400."
+    source_ref: "src/libretro.c:202"
+
+  - name: "sl90025.bin"
+    system: fairchild-channelf
+    required: false
+    md5: 95d339631d867c8f1d15a5f2ec26069d
+    size: 1024  # 1 KB, fills 0x000-0x3FF
+    note: "Channel F II PSU1 ROM. Tried first, preferred over sl31253.bin."
+    source_ref: "src/libretro.c:186"
+
+platform_details:
+  bios_mapping:
+    target: "0x000-0x7FF in 64K memory space"
+    source_ref: "src/memory.h:27-29, src/memory.c:30-61"
+    notes: |
+      MEMORY_loadSysROM_libretro() reads the file and copies it into
+      Memory[] at the given address offset. PSU1 is loaded at 0x000,
+      PSU2 at 0x400. The loader caps file size to (MEMORY_SIZE - address)
+      to prevent overflow. MEMORY_RAMStart is advanced past the loaded
+      ROM to protect it from writes.
+
+  hle_fallback:
+    source_ref: "src/channelf_hle.c"
+    notes: |
+      When BIOS files are missing, FreeChaF uses HLE to emulate the
+      PSU routines in software. This is marked as experimental and may
+      cause compatibility issues with some games. Each PSU can
+      independently fall back to HLE.
+
+  load_priority:
+    source_ref: "src/libretro.c:186-198"
+    notes: |
+      PSU1 loading order: sl90025.bin (Channel F II) first, then
+      sl31253.bin (original Channel F) as fallback. If both fail,
+      HLE is used. sl90025.bin is the preferred BIOS as it includes
+      Channel F II improvements.
diff --git a/emulators/freeintv.yml b/emulators/freeintv.yml
new file mode 100644
index 00000000..c81b8f5f
--- /dev/null
+++ b/emulators/freeintv.yml
@@ -0,0 +1,71 @@
+emulator: FreeIntv
+type: libretro
+source: "https://github.com/libretro/FreeIntv"
+cores:
+  - freeintv
+systems:
+  - intellivision
+
+notes: |
+  FreeIntv is a Mattel Intellivision emulator for libretro.
+
+  BIOS loading happens in retro_init() (src/libretro.c:1166-1174). The core
+  calls retro_get_system_directory() then joins exec.bin and grom.bin paths
+  directly. No subdirectory, no core option to disable BIOS loading.
+
+  loadExec() in src/intv.c:47-71 reads exec.bin as big-endian 16-bit words
+  into memory range 0x1000-0x1FFF (Executive ROM, 8 KB file).
+
+  loadGrom() in src/intv.c:73-98 reads grom.bin as raw bytes into memory
+  range 0x3000-0x37FF (Graphics ROM, 2 KB file).
+
+  Both files are required. Without them the core prints an error and shows
+  "PUT GROM/EXEC IN SYSTEM DIRECTORY" on the OSD, but does not abort.
+  Games will not run correctly without both BIOS files.
+
+  The .info file declares firmware_count = 2 with both marked opt = false.
+
+  No ECS (Entertainment Computer System) BIOS support exists in this core.
+  There is no ecs.bin loading code anywhere in the source.
+
+files:
+  - name: "exec.bin"
+    system: intellivision
+    required: true
+    size: 8192  # 8 KB (4096 x 16-bit words, 0x1000-0x1FFF)
+    md5: 62e761035cb657903761800f4437b8af
+    note: "Executive ROM. Big-endian 16-bit words loaded at 0x1000-0x1FFF."
+    source_ref: "src/intv.c:47-71, src/libretro.c:1169"
+
+  - name: "grom.bin"
+    system: intellivision
+    required: true
+    size: 2048  # 2 KB (bytes, 0x3000-0x37FF)
+    md5: 0cd5946c6473e42e8e4c2137785e427f
+    note: "Graphics ROM. Raw bytes loaded at 0x3000-0x37FF."
+    source_ref: "src/intv.c:73-98, src/libretro.c:1173"
+
+platform_details:
+  bios_mapping:
+    exec:
+      target: "0x1000-0x1FFF (Executive ROM)"
+      format: "big-endian 16-bit words"
+      source_ref: "src/intv.c:55-58"
+    grom:
+      target: "0x3000-0x37FF (Graphics ROM)"
+      format: "raw 8-bit bytes"
+      source_ref: "src/intv.c:81-84"
+    notes: |
+      Memory[] is a 64K array of unsigned int (src/memory.c:26).
+      EXEC region (0x1000-0x1FFF) is write-protected in writeMem()
+      (src/memory.c:60-61). GROM region (0x3000-0x37FF) is also
+      write-protected (src/memory.c:62).
+
+  cartridge_loading:
+    formats: "int, bin, rom"
+    methods: "Intellicart (magic byte 0xA8), raw ROM with fingerprint DB"
+    source_ref: "src/cart.c"
+    notes: |
+      Raw ROMs use a fingerprint database (sum of first 256 bytes)
+      to select one of 10 memory map configurations (load0-load9).
+      Intellicart format is auto-detected by 0xA8 magic byte.
diff --git a/emulators/fuse.yml b/emulators/fuse.yml
new file mode 100644
index 00000000..0160d8d5
--- /dev/null
+++ b/emulators/fuse.yml
@@ -0,0 +1,396 @@
+emulator: Fuse
+type: libretro
+source: "https://github.com/libretro/fuse-libretro"
+cores:
+  - fuse
+systems:
+  - sinclair-zxspectrum
+
+notes: |
+  Fuse (Free Unix Spectrum Emulator) ported to libretro. Emulates the ZX
+  Spectrum family: 16K, 48K, 48K NTSC, 128K, +2, +2A, +3, +3e, SE, Timex
+  TC2048, TC2068, TS2068, Pentagon 128K/512K/1024, and Scorpion 256K.
+
+  ROM loading is in src/compat/file.c:91-118. The core first checks an
+  internal table of embedded ROMs (mem_entries[]). If the ROM filename is
+  not found there, it falls back to the filesystem at
+  {system_dir}/fuse/{rom_filename} (file.c:160-175).
+
+  Embedded ROMs cover 48K-family, 128K, +2, +3, +3e, SE, TC2048, TC2068.
+  Pentagon, Scorpion, and peripheral ROMs are NOT embedded and must be
+  placed in {system_dir}/fuse/ by the user.
+
+  Default ROM filenames are set in fuse/settings.c:209-260. Each machine
+  type loads its ROMs during reset via machine_load_rom() calls in
+  fuse/machines/*.c files.
+
+  The +2A reuses the +3 ROMs (plus3-0/1/2/3.rom) per settings.c:234-237.
+  The TS2068 reuses TC2068 ROMs (tc2068-0/1.rom) per settings.c:257-258.
+  Spectrum 16K uses 48.rom per settings.c:211.
+
+files:
+  # -- Embedded ROMs (compiled into the core, not required on disk) --
+
+  - name: "fuse/48.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: 4c42a2f075212361c3117015b107ff68
+    sha1: 5ea7c2b824672e914525d1d5c419d71b84a426a2
+    size: 16384
+    note: "Spectrum 48K ROM. Also used for 16K and 48K NTSC. Embedded in core."
+    source_ref: "fuse/settings.c:211-212, fuse/machines/spec48.c:76"
+
+  - name: "fuse/128-0.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: b4d2692115a9f2924df92a3cbfb358fb
+    sha1: 4f4b11ec22326280bdb96e3baf9db4b4cb1d02c5
+    size: 16384
+    note: "Spectrum 128K ROM 0 (editor). Embedded in core."
+    source_ref: "fuse/settings.c:209, fuse/machines/spec128.c:70"
+
+  - name: "fuse/128-1.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: 6e09e5d3c4aef166601669feaaadc01c
+    sha1: 80080644289ed93d71a1103992a154cc9802b2fa
+    size: 16384
+    note: "Spectrum 128K ROM 1 (48 BASIC). Embedded in core."
+    source_ref: "fuse/settings.c:210, fuse/machines/spec128.c:73"
+
+  - name: "fuse/plus2-0.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: 4ed7af4636308b8a48d7a35e6c5b546b
+    sha1: 72703f9a3e734f3c23ec34c0727aae4ccbef9a91
+    size: 16384
+    note: "Spectrum +2 ROM 0. Embedded in core."
+    source_ref: "fuse/settings.c:232, fuse/machines/specplus2.c:70"
+
+  - name: "fuse/plus2-1.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: b3db95931cc844efaeb82db9c171b9f3
+    sha1: de8b0d2d0379cfe7c39322a086ca6da68c7f23cb
+    size: 16384
+    note: "Spectrum +2 ROM 1. Embedded in core."
+    source_ref: "fuse/settings.c:233, fuse/machines/specplus2.c:73"
+
+  - name: "fuse/plus3-0.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: 9833b8b73384dd5fa3678377ff00a2bb
+    sha1: e319ed08b4d53a5e421a75ea00ea02039ba6555b
+    size: 16384
+    note: "Spectrum +3 ROM 0. Also used for +2A. Embedded in core."
+    source_ref: "fuse/settings.c:234,238, fuse/machines/specplus3.c:197"
+
+  - name: "fuse/plus3-1.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: 0f711ceb5ab801b4701989982e0f334c
+    sha1: c9969fc36095a59787554026a9adc3b87678c794
+    size: 16384
+    note: "Spectrum +3 ROM 1. Also used for +2A. Embedded in core."
+    source_ref: "fuse/settings.c:235,239, fuse/machines/specplus3.c:200"
+
+  - name: "fuse/plus3-2.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: 3b6dd659d5e4ec97f0e2f7878152c987
+    sha1: 22e50c6ba4157a3f6a821bd9937cd26e292775c6
+    size: 16384
+    note: "Spectrum +3 ROM 2. Also used for +2A. Embedded in core."
+    source_ref: "fuse/settings.c:236,240, fuse/machines/specplus3.c:203"
+
+  - name: "fuse/plus3-3.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: a148bcc575e51389e84fdf5d555c3196
+    sha1: 65f031caa8148a5493afe42c41f4929deab26b4e
+    size: 16384
+    note: "Spectrum +3 ROM 3. Also used for +2A. Embedded in core."
+    source_ref: "fuse/settings.c:237,241, fuse/machines/specplus3.c:206"
+
+  - name: "fuse/plus3e-0.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: bc123f625e245c225f92ef05933ed134
+    sha1: 649fbd233490bf58b35350b0123d36caaaa011eb
+    size: 16384
+    note: "Spectrum +3e ROM 0. Embedded in core."
+    source_ref: "fuse/settings.c:242, fuse/machines/specplus3e.c:70"
+
+  - name: "fuse/plus3e-1.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: 617364264c587d20c9fc4746c29679f2
+    sha1: f12198108cbb14de4f03c6695bc16d08c85ee214
+    size: 16384
+    note: "Spectrum +3e ROM 1. Embedded in core."
+    source_ref: "fuse/settings.c:243, fuse/machines/specplus3e.c:73"
+
+  - name: "fuse/plus3e-2.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: c363e95dcd0a90e6e7f847e6e47e0179
+    sha1: 773633dce5ba323a9e00d9d0f9e4d8c295df7c87
+    size: 16384
+    note: "Spectrum +3e ROM 2. Embedded in core."
+    source_ref: "fuse/settings.c:244, fuse/machines/specplus3e.c:76"
+
+  - name: "fuse/plus3e-3.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: a148bcc575e51389e84fdf5d555c3196
+    sha1: 65f031caa8148a5493afe42c41f4929deab26b4e
+    size: 16384
+    note: "Spectrum +3e ROM 3. Same as plus3-3.rom. Embedded in core."
+    source_ref: "fuse/settings.c:245, fuse/machines/specplus3e.c:79"
+
+  - name: "fuse/se-0.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: fb3f86eb1e5a695d9c50c124e7cfb875
+    sha1: 8608328d7dd66602a4846f046b24fed500f7d828
+    size: 16384
+    note: "Spectrum SE ROM 0. Embedded in core."
+    source_ref: "fuse/settings.c:251, fuse/machines/spec_se.c:89"
+
+  - name: "fuse/se-1.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: 88de4a3129086f34bb9ca559acc51e6c
+    sha1: 3be5de57dd3bd0a9d15c57cabe9179afe2906a52
+    size: 16384
+    note: "Spectrum SE ROM 1. Embedded in core."
+    source_ref: "fuse/settings.c:252, fuse/machines/spec_se.c:92"
+
+  - name: "fuse/tc2048.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: 9dd7ecf784a6c04265c073c236f5fadb
+    sha1: febb2d495b6eda7cdcb4074935d6e9d9f328972d
+    size: 16384
+    note: "Timex TC2048 ROM. Embedded in core."
+    source_ref: "fuse/settings.c:254, fuse/machines/tc2048.c:80"
+
+  - name: "fuse/tc2068-0.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: 55d462fccc6c536037404ef4ced08bec
+    sha1: 1446cb2780a9dedf640404a639fa3ae518b2d8aa
+    size: 16384
+    note: "Timex TC2068 ROM 0. Also used for TS2068. Embedded in core."
+    source_ref: "fuse/settings.c:255,257, fuse/machines/tc2068.c:138"
+
+  - name: "fuse/tc2068-1.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: 575d203c6e15e679fba0b73f854ec7a2
+    sha1: 7e265a2c1f621ed365ea23bdcafdedbc79c1299c
+    size: 8192
+    note: "Timex TC2068 ROM 1 (EXROM). Also used for TS2068. Embedded in core."
+    source_ref: "fuse/settings.c:256,258, fuse/machines/tc2068.c:141"
+
+  # -- External ROMs (NOT embedded, must be in {system_dir}/fuse/) --
+
+  # Pentagon family
+  - name: "fuse/128p-0.rom"
+    system: sinclair-zxspectrum
+    required: true
+    md5: ""
+    size: 16384
+    note: "Pentagon 128K/512K/1024 ROM 0. Required for Pentagon machines."
+    source_ref: "fuse/settings.c:221,225,229, fuse/machines/pentagon.c:135"
+
+  - name: "fuse/128p-1.rom"
+    system: sinclair-zxspectrum
+    required: true
+    md5: ""
+    size: 16384
+    note: "Pentagon 128K/512K/1024 ROM 1. Required for Pentagon machines."
+    source_ref: "fuse/settings.c:222,226,230, fuse/machines/pentagon.c:138"
+
+  - name: "fuse/trdos.rom"
+    system: sinclair-zxspectrum
+    required: true
+    md5: ""
+    size: 16384
+    note: "TR-DOS ROM (Beta 128 disk interface). Used by Pentagon and Scorpion."
+    source_ref: "fuse/settings.c:223,227,231, fuse/machines/pentagon.c:141"
+
+  - name: "fuse/gluck.rom"
+    system: sinclair-zxspectrum
+    required: true
+    md5: ""
+    size: 16384
+    note: "Gluck ROM. Required for Pentagon 512K and 1024."
+    source_ref: "fuse/settings.c:224,228, fuse/machines/pentagon512.c:82"
+
+  # Scorpion
+  - name: "fuse/256s-0.rom"
+    system: sinclair-zxspectrum
+    required: true
+    md5: ""
+    size: 16384
+    note: "Scorpion 256K ROM 0. Required for Scorpion machine."
+    source_ref: "fuse/settings.c:247, fuse/machines/scorpion.c:76"
+
+  - name: "fuse/256s-1.rom"
+    system: sinclair-zxspectrum
+    required: true
+    md5: ""
+    size: 16384
+    note: "Scorpion 256K ROM 1. Required for Scorpion machine."
+    source_ref: "fuse/settings.c:248, fuse/machines/scorpion.c:79"
+
+  - name: "fuse/256s-2.rom"
+    system: sinclair-zxspectrum
+    required: true
+    md5: ""
+    size: 16384
+    note: "Scorpion 256K ROM 2. Required for Scorpion machine."
+    source_ref: "fuse/settings.c:249, fuse/machines/scorpion.c:82"
+
+  - name: "fuse/256s-3.rom"
+    system: sinclair-zxspectrum
+    required: true
+    md5: ""
+    size: 16384
+    note: "Scorpion 256K ROM 3 (TR-DOS). Required for Scorpion machine."
+    source_ref: "fuse/settings.c:250, fuse/machines/scorpion.c:85"
+
+  # Peripheral ROMs (optional, only needed if peripheral is enabled)
+  - name: "fuse/if1-2.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: ""
+    size: 16384
+    note: "Interface 1 ROM (edition 2). Loaded by peripherals/if1.c:403."
+    source_ref: "fuse/settings.c:216, fuse/peripherals/if1.c:403"
+
+  - name: "fuse/disciple.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: 78e61a2a02121873c1756b21fd1398b1
+    sha1: 9a75ed4b293f968985be4c9aa893cd88276d1ced
+    size: 8192
+    note: "DISCiPLE disk interface ROM. Bundled in repo but not in mem_entries[]."
+    source_ref: "fuse/settings.c:215, fuse/peripherals/disk/disciple.c:279"
+
+  - name: "fuse/plusd.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: 42e5de16fb5e50082bb954ec7ce45851
+    sha1: 6b841dc5797ef7eb219ad455cd1e434ca3b9d30d
+    size: 8192
+    note: "+D disk interface ROM. Bundled in repo but not in mem_entries[]."
+    source_ref: "fuse/settings.c:246, fuse/peripherals/disk/plusd.c:239"
+
+  - name: "fuse/didaktik80.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: ""
+    note: "Didaktik 80 disk interface ROM. Not embedded."
+    source_ref: "fuse/settings.c:214, fuse/peripherals/disk/didaktik.c:236"
+
+  - name: "fuse/opus.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: ""
+    note: "Opus Discovery disk interface ROM. Not embedded."
+    source_ref: "fuse/settings.c:220, fuse/peripherals/disk/opus.c:210"
+
+  - name: "fuse/mf1.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: ""
+    note: "Multiface 1 ROM. Not embedded."
+    source_ref: "fuse/settings.c:217, fuse/peripherals/multiface.c:224"
+
+  - name: "fuse/mf128.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: ""
+    note: "Multiface 128 ROM. Not embedded."
+    source_ref: "fuse/settings.c:218, fuse/peripherals/multiface.c:225"
+
+  - name: "fuse/mf3.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: ""
+    note: "Multiface 3 ROM. Not embedded."
+    source_ref: "fuse/settings.c:219, fuse/peripherals/multiface.c:226"
+
+  - name: "fuse/speccyboot-1.4.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: c54aa8f374b0971f51546c29d5d1eba1
+    sha1: 16af6f052b38a027dd49ba6e96e3a59d16b62672
+    size: 8192
+    note: "SpeccyBoot ethernet ROM. Bundled in repo but not in mem_entries[]."
+    source_ref: "fuse/settings.c:253, fuse/peripherals/speccyboot.c:148"
+
+  - name: "fuse/ttx2000s.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: ""
+    note: "TTX2000S teletext adapter ROM. Not embedded."
+    source_ref: "fuse/settings.c:259, fuse/peripherals/ttx2000s.c:198"
+
+  - name: "fuse/usource.rom"
+    system: sinclair-zxspectrum
+    required: false
+    md5: ""
+    note: "Currah uSource ROM. Not embedded."
+    source_ref: "fuse/settings.c:260, fuse/peripherals/usource.c:129"
+
+platform_details:
+  bios_mapping:
+    source_ref: "src/compat/file.c:55-89, 129-223"
+    notes: |
+      ROM resolution order in compat_file_open():
+      1. Check mem_entries[] (18 embedded ROMs compiled as .h arrays)
+      2. If not found, try {system_dir}/fuse/{filename} on filesystem
+      The path is constructed by concatenating system_dir + "/fuse" + path
+      where path includes the leading slash from fuse's internal path.
+
+  embedded_roms:
+    source_ref: "src/compat/file.c:55-73"
+    notes: |
+      18 ROMs embedded in the binary via .h headers generated from .rom files:
+      48.rom, 128-0.rom, 128-1.rom, plus2-0.rom, plus2-1.rom,
+      plus3-0/1/2/3.rom, plus3e-0/1/2/3.rom, se-0.rom, se-1.rom,
+      tc2048.rom, tc2068-0.rom, tc2068-1.rom.
+      disciple.rom, plusd.rom, speccyboot-1.4.rom are present in the repo
+      fuse/roms/ directory but NOT in mem_entries[], so they are loaded
+      from the filesystem only.
+
+  machine_rom_map:
+    source_ref: "fuse/settings.c:209-260, fuse/machines/*.c"
+    notes: |
+      Spectrum 16K:       48.rom (1 ROM)
+      Spectrum 48K:       48.rom (1 ROM)
+      Spectrum 48K NTSC:  48.rom (1 ROM)
+      Spectrum 128K:      128-0.rom, 128-1.rom (2 ROMs)
+      Spectrum +2:        plus2-0.rom, plus2-1.rom (2 ROMs)
+      Spectrum +2A:       plus3-0.rom, plus3-1.rom, plus3-2.rom, plus3-3.rom (4 ROMs)
+      Spectrum +3:        plus3-0.rom, plus3-1.rom, plus3-2.rom, plus3-3.rom (4 ROMs)
+      Spectrum +3e:       plus3e-0/1/2/3.rom (4 ROMs)
+      Spectrum SE:        se-0.rom, se-1.rom (2 ROMs)
+      Timex TC2048:       tc2048.rom (1 ROM)
+      Timex TC2068:       tc2068-0.rom, tc2068-1.rom (2 ROMs)
+      Timex TS2068:       tc2068-0.rom, tc2068-1.rom (2 ROMs, same files)
+      Pentagon 128K:      128p-0.rom, 128p-1.rom, trdos.rom (3 ROMs)
+      Pentagon 512K:      128p-0.rom, 128p-1.rom, trdos.rom, gluck.rom (4 ROMs)
+      Pentagon 1024:      128p-0.rom, 128p-1.rom, trdos.rom, gluck.rom (4 ROMs)
+      Scorpion 256K:      256s-0.rom, 256s-1.rom, 256s-2.rom, 256s-3.rom (4 ROMs)
+
+  rom_copyright:
+    source_ref: "fuse/roms/README.copyright"
+    notes: |
+      Most ROMs are copyright Amstrad. Amstrad allows free distribution but
+      retains copyright. Selling ROMs standalone is not permitted. SE ROMs
+      are GPLv2+. DISCiPLE/+D ROMs are copyright Datel, distribution allowed.
+      SpeccyBoot ROM is MIT licensed.
diff --git a/emulators/gambatte.yml b/emulators/gambatte.yml
new file mode 100644
index 00000000..e59ac3f0
--- /dev/null
+++ b/emulators/gambatte.yml
@@ -0,0 +1,53 @@
+emulator: Gambatte
+type: libretro
+source: "https://github.com/libretro/gambatte-libretro"
+systems: [nintendo-gb, nintendo-gbc]
+
+notes: |
+  Gambatte is a Game Boy / Game Boy Color emulator focused on accuracy.
+  No BIOS is required for normal operation. The core has a built-in
+  HLE boot sequence that skips the Nintendo logo animation by default.
+
+  When the core option "gambatte_gb_bootloader" is set to "enabled"
+  (the default), the core looks for official boot ROMs in the system
+  directory to play the real startup logo animation. If the files are
+  missing, emulation still works without them.
+
+  The boot ROM loaded depends on the hardware mode:
+  - DMG (original Game Boy): gb_bios.bin (256 bytes, 0x100)
+  - CGB (Game Boy Color) or GBA mode: gbc_bios.bin (2304 bytes, 0x900)
+
+  In GBA mode the core patches the CGB boot ROM at 0xF2 to fake
+  GBA detection (ld b,0x01), enabling GBA-enhanced features in
+  compatible GBC games (Shantae, Zelda Oracle series, etc.).
+
+  File path construction: libretro.cpp get_bootloader_from_file()
+  joins RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY with each filename
+  directly - no subdirectories.
+
+  Gambatte does NOT use sgb_bios.bin. The SGB palette references in
+  the source are color lookup tables for DMG palette colorization,
+  not actual Super Game Boy boot ROM loading.
+
+files:
+  # --- DMG boot ROM (optional, enables startup animation) ---
+  - name: "gb_bios.bin"
+    system: nintendo-gb
+    description: "Original Game Boy (DMG-01) boot ROM"
+    required: false
+    size: 256
+    md5: "32fbbd84168d3482956eb3c5051637f5"
+    sha1: "4ed31ec6b0b175bb109c0eb5fd3d193da823339f"
+    source_ref: "libretro.cpp:1304-1364 (get_bootloader_from_file), bootloader.cpp:20-55 (load)"
+    notes: "Mapped at 0x0000-0x00FF, swapped out when register 0xFF50 is written. Core option gambatte_gb_bootloader must be enabled."
+
+  # --- CGB boot ROM (optional, enables startup animation) ---
+  - name: "gbc_bios.bin"
+    system: nintendo-gbc
+    description: "Game Boy Color (CGB-001) boot ROM"
+    required: false
+    size: 2304
+    md5: "dbfce9db9deaa2567f6a84fde55f9680"
+    sha1: "1293d68bf9643bc4f36954c1e80e38f39864528d"
+    source_ref: "libretro.cpp:1304-1364 (get_bootloader_from_file), bootloader.cpp:20-55 (load)"
+    notes: "Mapped at 0x0000-0x08FF with cartridge data preserved at 0x0100-0x01FF. Also used for GBA-enhanced mode with a patch at 0xF2. Presence required for FORCE_CGB flag when hw mode is set to GBC or GBA."
diff --git a/emulators/kronos.yml b/emulators/kronos.yml
new file mode 100644
index 00000000..213cf382
--- /dev/null
+++ b/emulators/kronos.yml
@@ -0,0 +1,238 @@
+emulator: Kronos
+type: libretro
+cores:
+  - kronos_libretro
+  - yabause_libretro
+source: "https://github.com/FCare/Kronos"
+systems:
+  - sega-saturn
+  - sega-stv
+
+notes: |
+  Kronos is a Sega Saturn and ST-V arcade emulator forked from Yabause.
+  The libretro repo at libretro/yabause ships the older "Yabause" core
+  (yabause_libretro) which handles Saturn only and has no STV support.
+
+  Saturn BIOS search order (Kronos):
+    1. {system}/kronos/saturn_bios.bin
+    2. {system}/saturn_bios.bin
+    3. {system}/sega_101.bin
+    4. {system}/mpr-17933.bin
+  First file found wins. Real BIOS required, HLE is deprecated and causes
+  issues. Multi-disc (m3u) also forces real BIOS.
+
+  Saturn BIOS search order (YabaSanshiro / Yabause):
+    1. {system}/saturn_bios.bin
+    2. {system}/sega_101.bin
+    3. {system}/mpr-17933.bin
+  Falls back to HLE if none found, but HLE is not recommended.
+
+  ST-V BIOS (Kronos only):
+    {system}/kronos/stvbios.zip or {system}/stvbios.zip
+  The ZIP is a MAME-style romset containing region-specific EPROMs.
+  Kronos picks the first matching BIOS by region, with a configurable
+  "favorite region" core option (EU/US/JP/TW). The ZIP must contain
+  at least one of the BIOS blobs listed below. ST-V games are detected
+  automatically when loading a .zip file.
+
+  BIOS loading: libretro.c retro_load_game() lines 1601-1727.
+  STV blob table: ctrl/src/stv.c BiosList lines 112-136.
+  Region enums: ctrl/include/stv.h lines 47-52.
+
+files:
+  # -----------------------------------------------------------
+  # Saturn BIOS - generic (any region accepted)
+  # -----------------------------------------------------------
+  - name: "saturn_bios.bin"
+    system: sega-saturn
+    required: true
+    size: 524288  # 512 KB (0x80000)
+    note: "Primary Saturn BIOS. Any region. Searched first by both cores."
+    source_ref: "libretro.c:1619-1623 (kronos), libretro.c:1035 (yabause)"
+
+  # -----------------------------------------------------------
+  # Saturn BIOS - Japan v1.01
+  # -----------------------------------------------------------
+  - name: "sega_101.bin"
+    system: sega-saturn
+    region: [japan]
+    required: false
+    size: 524288
+    md5: "85ec9ca47d8f6807718151cbcca8b964"
+    note: "Saturn BIOS v1.01 (Japan). Fallback if saturn_bios.bin missing."
+    source_ref: "libretro.c:1627 (kronos), libretro.c:1039 (yabause)"
+
+  # -----------------------------------------------------------
+  # Saturn BIOS - NA/EU
+  # -----------------------------------------------------------
+  - name: "mpr-17933.bin"
+    system: sega-saturn
+    region: [north-america, europe]
+    required: false
+    size: 524288
+    md5: "3240872c70984b6cbfda1586cab68dbe"
+    note: "Saturn BIOS (NA/EU). Last fallback for Saturn mode."
+    source_ref: "libretro.c:1631 (kronos), libretro.c:1043 (yabause)"
+
+  # -----------------------------------------------------------
+  # ST-V Arcade BIOS (stvbios.zip) - Kronos only
+  # -----------------------------------------------------------
+  - name: "stvbios.zip"
+    system: sega-stv
+    required: true
+    note: >
+      MAME-style ZIP containing ST-V region BIOS EPROMs. Required for
+      ST-V arcade games. Kronos picks the best match based on game
+      region and the stv_favorite_region core option. At least one
+      BIOS blob must be present. Searched in kronos/ subdir first.
+    source_ref: "libretro.c:1608-1617, ctrl/src/stv.c:112-136"
+
+  # -----------------------------------------------------------
+  # ST-V BIOS blobs inside stvbios.zip
+  # -----------------------------------------------------------
+
+  # Japan
+  - name: "epr-23603.ic8"
+    system: sega-stv
+    region: [japan]
+    required: false
+    size: 524288
+    crc32: "f688ae60"
+    note: "STV BIOS Japan (latest). Inside stvbios.zip."
+    source_ref: "stv.c:120"
+
+  - name: "epr-20091.ic8"
+    system: sega-stv
+    region: [japan]
+    required: false
+    size: 524288
+    crc32: "59ed40f4"
+    note: "STV BIOS Japan v1. Inside stvbios.zip."
+    source_ref: "stv.c:121"
+
+  - name: "epr-19730.ic8"
+    system: sega-stv
+    region: [japan]
+    required: false
+    size: 524288
+    crc32: "d0e0889d"
+    note: "STV BIOS Japan v2. Inside stvbios.zip."
+    source_ref: "stv.c:122"
+
+  - name: "epr-17951a.ic8"
+    system: sega-stv
+    region: [japan]
+    required: false
+    size: 524288
+    crc32: "2672f9d8"
+    note: "STV BIOS Japan v3. Inside stvbios.zip."
+    source_ref: "stv.c:123"
+
+  - name: "epr-17740a.ic8"
+    system: sega-stv
+    region: [japan]
+    required: false
+    size: 524288
+    crc32: "3e23c81f"
+    note: "STV BIOS Japan v4. Inside stvbios.zip."
+    source_ref: "stv.c:124"
+
+  - name: "epr-17740.ic8"
+    system: sega-stv
+    region: [japan]
+    required: false
+    size: 524288
+    crc32: "5c5aa63d"
+    note: "STV BIOS Japan v5. Inside stvbios.zip."
+    source_ref: "stv.c:125"
+
+  # Europe
+  - name: "epr-17954a.ic8"
+    system: sega-stv
+    region: [europe]
+    required: false
+    size: 524288
+    crc32: "f7722da3"
+    note: "STV BIOS Europe. Inside stvbios.zip."
+    source_ref: "stv.c:126"
+
+  # USA
+  - name: "epr-17952a.ic8"
+    system: sega-stv
+    region: [north-america]
+    required: false
+    size: 524288
+    crc32: "d1be2adf"
+    note: "STV BIOS USA. Inside stvbios.zip."
+    source_ref: "stv.c:127"
+
+  - name: "epr-17741a.ic8"
+    system: sega-stv
+    region: [north-america]
+    required: false
+    size: 524288
+    crc32: "4166c663"
+    note: "STV BIOS USA v1. Inside stvbios.zip."
+    source_ref: "stv.c:128"
+
+  # Taiwan
+  - name: "epr-19854.ic8"
+    system: sega-stv
+    region: [taiwan]
+    required: false
+    size: 524288
+    crc32: "e09d1f60"
+    note: "STV BIOS Taiwan. Inside stvbios.zip."
+    source_ref: "stv.c:129"
+
+  - name: "epr-17953a.ic8"
+    system: sega-stv
+    region: [taiwan]
+    required: false
+    size: 524288
+    crc32: "a4c47570"
+    note: "STV BIOS Taiwan v1. Inside stvbios.zip."
+    source_ref: "stv.c:130"
+
+  - name: "epr-17742a.ic8"
+    system: sega-stv
+    region: [taiwan]
+    required: false
+    size: 524288
+    crc32: "02daf123"
+    note: "STV BIOS Taiwan v2. Inside stvbios.zip."
+    source_ref: "stv.c:131"
+
+  # Debug / Dev
+  - name: "stv110.bin"
+    system: sega-stv
+    required: false
+    size: 524288
+    crc32: "3dfeda92"
+    note: "STV debug BIOS. Inside stvbios.zip. Not used in normal operation."
+    source_ref: "stv.c:132"
+
+  - name: "stv1061.bin"
+    system: sega-stv
+    required: false
+    size: 524288
+    crc32: "728dbca3"
+    note: "STV dev BIOS. Inside stvbios.zip. Not used in normal operation."
+    source_ref: "stv.c:133"
+
+platform_details:
+  saturn:
+    bios_size: 524288
+    bios_address: "0x00000000-0x0007FFFF"
+    hle_available: true
+    hle_recommended: false
+    kronos_bios_subdir: "kronos"
+    source_ref: "sys/memory/src/memory.c:1346, libretro.c:1619-1638"
+  stv:
+    bios_format: "MAME-style ZIP (stvbios.zip)"
+    blob_size: 524288
+    blob_load_address: "0x000000"
+    regions: [japan, europe, north-america, taiwan]
+    region_selection: "automatic per game, overridable via kronos_stv_favorite_region"
+    kronos_bios_subdir: "kronos"
+    source_ref: "ctrl/src/stv.c:112-136, ctrl/include/stv.h:47-52"
diff --git a/emulators/mgba.yml b/emulators/mgba.yml
new file mode 100644
index 00000000..e94e0ac4
--- /dev/null
+++ b/emulators/mgba.yml
@@ -0,0 +1,118 @@
+emulator: mGBA
+type: libretro
+source: "https://github.com/libretro/mgba"
+cores:
+  - mgba
+systems:
+  - nintendo-gba
+  - nintendo-gb
+  - nintendo-gbc
+  - nintendo-sgb
+
+notes: |
+  mGBA is a Game Boy Advance emulator with Game Boy, Game Boy Color, and
+  Super Game Boy support.
+
+  All BIOS files are optional. mGBA ships a built-in HLE BIOS for GBA
+  (src/gba/hle-bios.c) that covers most software. The real BIOS improves
+  accuracy (startup logo, some edge-case SWI behavior). There is no HLE
+  BIOS for GB/GBC/SGB -- those rely on GBSkipBIOS() if no file is found.
+
+  BIOS loading is controlled by two core options:
+    mgba_use_bios (default ON)  - whether to look for BIOS files at all
+    mgba_skip_bios (default OFF) - skip the boot animation even if loaded
+
+  The libretro port resolves BIOS filenames in retro_load_game()
+  (src/platform/libretro/libretro.c:2091-2148). It picks the filename
+  based on detected model:
+    GBA           -> gba_bios.bin
+    GB (DMG/MGB)  -> gb_bios.bin
+    GBC (CGB/AGB) -> gbc_bios.bin
+    SGB (SGB/SGB2)-> sgb_bios.bin
+
+  The standalone core (src/gb/core.c:637-684) handles the same models
+  and maps SGB2 to sgb_bios.bin (marked TODO for a dedicated file).
+
+  GBIsBIOS() in src/gb/gb.c validates BIOS files by CRC32 checksum.
+  Accepted checksums cover DMG, DMG0, MGB, SGB, SGB2, CGB, CGB0, CGBE,
+  AGB, and AGB0 revisions.
+
+files:
+  # -------------------------------------------------------
+  # Game Boy Advance - BIOS (optional, HLE fallback)
+  # -------------------------------------------------------
+  - name: gba_bios.bin
+    system: nintendo-gba
+    required: false
+    size: 16384  # 16 KB (0x4000, GBA_SIZE_BIOS)
+    note: "GBA BIOS. HLE replacement built in. Real BIOS adds boot logo and full SWI accuracy."
+    source_ref: "src/platform/libretro/libretro.c:2099"
+
+  # -------------------------------------------------------
+  # Game Boy - boot ROM (optional, skip fallback)
+  # -------------------------------------------------------
+  - name: gb_bios.bin
+    system: nintendo-gb
+    required: false
+    size: 256  # 256 B (0x100)
+    note: "DMG/MGB boot ROM. Scrolling Nintendo logo. Skipped if absent."
+    source_ref: "src/platform/libretro/libretro.c:2134"
+
+  # -------------------------------------------------------
+  # Game Boy Color - boot ROM (optional, skip fallback)
+  # -------------------------------------------------------
+  - name: gbc_bios.bin
+    system: nintendo-gbc
+    required: false
+    size: 2304  # 2304 B (0x900)
+    note: "CGB boot ROM. Used for CGB, AGB (GBA in GB mode), and SCGB models."
+    source_ref: "src/platform/libretro/libretro.c:2127"
+
+  # -------------------------------------------------------
+  # Super Game Boy - boot ROM (optional, skip fallback)
+  # -------------------------------------------------------
+  - name: sgb_bios.bin
+    system: nintendo-sgb
+    required: false
+    size: 256  # 256 B (0x100)
+    note: "SGB/SGB2 boot ROM. Also used when model is SGB2 (no separate sgb2_bios.bin)."
+    source_ref: "src/platform/libretro/libretro.c:2130"
+
+platform_details:
+  gba:
+    bios_size: 16384  # 16 KB
+    hle_bios: true
+    source_ref: "src/gba/hle-bios.c, src/gba/gba.c:520-548"
+    notes: |
+      GBALoadBIOS() validates size (must be exactly 0x4000) then computes
+      an internal checksum. Two official checksums are recognized:
+        GBA_BIOS_CHECKSUM    = 0xBAAE187F (standard GBA)
+        GBA_DS_BIOS_CHECKSUM = 0xBAAE1880 (DS GBA mode)
+      Other checksums trigger a warning but the file is still loaded.
+
+  gb:
+    bios_size: 256  # 256 B
+    hle_bios: false
+    source_ref: "src/gb/gb.c:570-605"
+    notes: |
+      GBIsBIOS() validates by CRC32. Accepted DMG-family checksums:
+        DMG0 = 0xC2F5CC97, DMG = 0x59C8598E, MGB = 0xE6920754
+      Files not matching any known checksum are rejected.
+
+  gbc:
+    bios_size: 2304  # 2304 B (0x900)
+    hle_bios: false
+    source_ref: "src/gb/gb.c:570-605"
+    notes: |
+      Accepted CGB-family CRC32 checksums:
+        CGB = 0x41884E46, CGB0 = 0xE8EF5318, CGBE = 0xE95DC95D
+        AGB = 0xFFD6B0F1, AGB0 = 0x570337EA
+
+  sgb:
+    bios_size: 256  # 256 B
+    hle_bios: false
+    source_ref: "src/gb/gb.c:570-605, src/gb/core.c:642-644"
+    notes: |
+      Accepted SGB CRC32 checksums:
+        SGB = 0xEC8A83B9, SGB2 = 0x53D0DD63
+      SGB2 model falls through to sgb_bios.bin (marked TODO upstream).
diff --git a/emulators/nestopia.yml b/emulators/nestopia.yml
new file mode 100644
index 00000000..12fcd3cf
--- /dev/null
+++ b/emulators/nestopia.yml
@@ -0,0 +1,67 @@
+emulator: Nestopia UE
+type: libretro
+source: "https://github.com/libretro/nestopia"
+systems: [nintendo-nes, nintendo-fds]
+
+notes: |
+  Nestopia UE (Undead Edition) is a cycle-accurate NES/Famicom emulator.
+  NES cartridge games need no BIOS. Famicom Disk System games require
+  the FDS BIOS ROM (disksys.rom, 8 KB) loaded from the system directory.
+  The core validates the BIOS via CRC32 against two known dumps:
+  standard Famicom (0x5E607DCF) and Twin Famicom (0x4DF24A6C).
+  An unknown BIOS triggers a warning but still loads.
+
+  NstDatabase.xml is an optional game database used for region autodetection,
+  aspect ratio selection, and 4-player adapter recognition. A copy is baked
+  into the core binary (libretro/nstdatabase.hpp) and used as fallback when
+  no external file is found. Placing a newer NstDatabase.xml in the system
+  directory overrides the built-in copy.
+
+  An optional custom palette file (custom.pal, 192 bytes, 64 RGB triplets)
+  overrides the built-in palettes when the nestopia_palette core option is
+  set to Custom. The core ships with 10+ built-in palettes (Royaltea,
+  Smooth FBx, etc.) so the external file is rarely needed.
+
+  Audio samples for specific games can be placed in system/nestopia/samples/
+  as numbered .wav files (e.g., 00.wav, 01.wav). This is used for Famicom
+  expansion audio in a few titles.
+
+  Game Genie is handled as cheat code decoding (software), not via a ROM file.
+
+  File path construction: libretro/libretro.cpp retro_load_game() joins the
+  system directory (RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY) with each
+  filename directly - no subdirectories.
+
+files:
+  # --- Famicom Disk System BIOS (required for FDS games) ---
+  - name: "disksys.rom"
+    system: nintendo-fds
+    description: "FDS BIOS ROM"
+    required: true
+    size: 8192
+    md5: "ca30b50f880eb660a320674ed365ef7a"
+    sha1: "57fe1bdee955bb48d357e463ccbf129496930b62"
+    source_ref: "libretro/libretro.cpp:1608-1634 (FDS load), source/core/NstFds.cpp:61-131 (Bios class, CRC32 validation)"
+    notes: "Mapped at 0xE000-0xFFFF (8 KB). retro_load_game returns false if missing when loading .fds files. CRC32 checked: Famicom 0x5E607DCF, Twin Famicom 0x4DF24A6C."
+
+  # --- NES game database (optional, overrides baked-in copy) ---
+  - name: "NstDatabase.xml"
+    system: nintendo-nes
+    description: "Nestopia game database for region and mapper autodetection"
+    required: false
+    size: 1022369
+    md5: "0ee6cbdc6f5c96ce9c8aa5edb59066f4"
+    sha1: ~
+    source_ref: "libretro/libretro.cpp:1561-1586 (database load), libretro/nstdatabase.hpp (baked-in fallback)"
+    notes: "XML database matching games by SHA1+CRC32. Used for region, mapper, mirroring, and 4-player adapter detection. Built-in fallback exists so this file is optional. Hash is for the upstream copy shipped with the core repo."
+
+  # --- Custom palette (optional, core option nestopia_palette = Custom) ---
+  - name: "custom.pal"
+    system: nintendo-nes
+    description: "External NES color palette"
+    required: false
+    size: 192
+    md5: ~
+    sha1: ~
+    source_ref: "libretro/libretro.cpp:1540-1559 (palette load)"
+    notes: "64 RGB triplets (64 x 3 bytes = 192 bytes). Only loaded when nestopia_palette core option is set to Custom. Falls back to built-in Royaltea palette if not found. Multiple valid palettes exist so no single canonical hash."
diff --git a/emulators/o2em.yml b/emulators/o2em.yml
new file mode 100644
index 00000000..0bba3f80
--- /dev/null
+++ b/emulators/o2em.yml
@@ -0,0 +1,98 @@
+emulator: O2EM
+type: libretro
+core: o2em_libretro
+source: "https://github.com/libretro/libretro-o2em"
+systems:
+  - odyssey2
+  - videopac
+
+notes: |
+  O2EM is the libretro port of the Odyssey2/Videopac emulator.
+  The core requires exactly one BIOS ROM selected via the o2em_bios core option.
+  Default is o2rom.bin (Odyssey2 NTSC). The user can switch to c52.bin, g7400.bin
+  or jopac.bin for European/French Videopac variants.
+
+  BIOS files are loaded from the system directory into rom_table[0] (1024 bytes).
+  The core identifies the BIOS variant by CRC32 and sets the vpp flag accordingly
+  (vpp=1 enables Videopac+ enhanced graphics for g7400.bin and jopac.bin).
+
+  The core will not start without a valid BIOS file present.
+  Any single BIOS from the list below is sufficient for its region/hardware.
+
+  All BIOS files are exactly 1 KB (1024 bytes).
+
+  BIOS detection: libretro.c load_bios() lines 146-212, CRC32 switch.
+  BIOS selection: libretro_core_options.h o2em_bios option lines 52-64.
+  Core option handling: libretro.c lines 1107-1134.
+
+files:
+  # -------------------------------------------------------
+  # Magnavox Odyssey2 (NTSC) - G7000 model
+  # -------------------------------------------------------
+  - name: "o2rom.bin"
+    system: odyssey2
+    region: [north-america]
+    required: true
+    size: 1024
+    md5: "562d5ebf9e030a40d6fabfc2f33139fd"
+    sha1: "b2e1955d957a475de2411770452eff4ea19f4cee"
+    crc32: "8016a315"
+    note: "Magnavox Odyssey2 BIOS (G7000 NTSC). Default BIOS, vpp=0."
+    source_ref: "libretro.c:182-186"
+
+  # -------------------------------------------------------
+  # Philips Videopac G7000 (European)
+  # -------------------------------------------------------
+  - name: "c52.bin"
+    system: videopac
+    region: [europe]
+    required: true
+    size: 1024
+    md5: "f1071cdb0b6b10dde94d3bc8a6146387"
+    sha1: "a6120aed50831c9c0d95dbdf707820f601d9452e"
+    crc32: "a318e8d6"
+    note: "Philips Videopac G7000 European BIOS. vpp=0, auto-sets PAL region."
+    source_ref: "libretro.c:192-197"
+
+  # -------------------------------------------------------
+  # Philips Videopac+ G7400 (European)
+  # -------------------------------------------------------
+  - name: "g7400.bin"
+    system: videopac
+    region: [europe]
+    required: true
+    size: 1024
+    md5: "c500ff71236068e0dc0d0603d265ae76"
+    sha1: "5130243429b40b01a14e1304d0394b8459a6fbae"
+    crc32: "e20a9f41"
+    note: "Philips Videopac+ G7400 European BIOS. vpp=1, enables enhanced graphics."
+    source_ref: "libretro.c:187-191"
+
+  # -------------------------------------------------------
+  # Philips Videopac+ G7400 (French) - JoPac
+  # -------------------------------------------------------
+  - name: "jopac.bin"
+    system: videopac
+    region: [france]
+    required: true
+    size: 1024
+    md5: "279008e4a0db2dc5f1c048853b033828"
+    sha1: "54b8d2c1317628de51a85fc1c424423a986775e4"
+    crc32: "11647ca5"
+    note: "Philips Videopac+ G7400 French BIOS (JoPac). vpp=1, enables enhanced graphics."
+    source_ref: "libretro.c:198-203"
+
+platform_details:
+  odyssey2:
+    bios_size: 1024
+    bios_selection: "core option o2em_bios, default o2rom.bin"
+    detection_method: "CRC32 of 1024-byte ROM"
+    hle_available: false
+    source_ref: "libretro.c:146-212, libretro_core_options.h:52-64"
+  videopac:
+    bios_size: 1024
+    bios_selection: "core option o2em_bios, choose c52/g7400/jopac"
+    detection_method: "CRC32 of 1024-byte ROM"
+    vpp_flag: "g7400.bin and jopac.bin set vpp=1 for enhanced graphics"
+    hle_available: false
+    source_ref: "libretro.c:146-212, libretro_core_options.h:52-64"
diff --git a/emulators/px68k.yml b/emulators/px68k.yml
new file mode 100644
index 00000000..16a345f0
--- /dev/null
+++ b/emulators/px68k.yml
@@ -0,0 +1,110 @@
+emulator: px68k
+type: libretro
+source: "https://github.com/libretro/px68k-libretro"
+cores:
+  - px68k
+systems:
+  - sharp-x68000
+
+# PX68K is a Sharp X68000 emulator (originally Keropi) ported to libretro.
+# All ROM files are loaded from <system_dir>/keropi/ subdirectory.
+#
+# ROM loading (libretro.c:848-893 WinX68k_LoadROMs):
+#   1. Base path set to <system_dir>/keropi/ via file_setcd(winx68k_dir) at line 969
+#   2. IPL ROM: iterates BIOSFILE[] = {iplrom.dat, iplrom30.dat, iplromco.dat, iplromxv.dat}
+#      and opens the first file found. Reads 0x20000 bytes (128 KB) into IPL buffer.
+#      Returns 0 (failure) if none found -- core will not start.
+#   3. SCSI check (WinX68k_SCSICheck): if IPL contains SCSI vectors at offset 0x30600-0x30c00,
+#      patches a fake SCSI BIOS stub at $fc0000 with "Human68k" signature.
+#   4. Byte-swaps IPL in 16-bit pairs (big-endian ROM on little-endian host).
+#   5. Font ROM: opens cgrom.dat, falls back to cgrom.tmp if not found.
+#      Reads 0xc0000 bytes (768 KB) into FONT buffer. Returns 0 if neither exists.
+#
+# SRAM (x68k/sram.c:50-73):
+#   sram.dat is 16 KB of battery-backed SRAM, loaded on init and saved on cleanup.
+#   Not a BIOS -- runtime state. Created automatically if missing.
+#
+# Directory layout expected:
+#   <system_dir>/keropi/iplrom.dat     (or iplrom30.dat, iplromco.dat, iplromxv.dat)
+#   <system_dir>/keropi/cgrom.dat      (or cgrom.tmp)
+#   <system_dir>/keropi/sram.dat       (auto-created)
+#   <system_dir>/keropi/config         (auto-created, core settings)
+
+files:
+  # IPL ROM -- the main system BIOS. The core tries four filenames in order and
+  # uses the first one found. Only one is needed. iplrom.dat is the original X68000,
+  # iplrom30.dat is X68030, iplromco.dat is X68000 Compact, iplromxv.dat is X68000 XVI.
+
+  - name: "iplrom.dat"
+    path: "keropi/iplrom.dat"
+    size: 131072
+    required: true
+    note: >
+      X68000 IPL ROM (original model). 128 KB, loaded at IPL buffer offset 0x20000.
+      The core tries iplrom.dat first, then iplrom30.dat, iplromco.dat, iplromxv.dat
+      in order. At least one must be present or the core fails to start.
+    source_ref: "libretro.c:850-867"
+
+  - name: "iplrom30.dat"
+    path: "keropi/iplrom30.dat"
+    size: 131072
+    required: false
+    note: >
+      X68030 IPL ROM. Alternative to iplrom.dat for X68030 model emulation.
+      Only used if iplrom.dat is not found.
+    source_ref: "libretro.c:851"
+
+  - name: "iplromco.dat"
+    path: "keropi/iplromco.dat"
+    size: 131072
+    required: false
+    note: >
+      X68000 Compact IPL ROM. Alternative to iplrom.dat.
+      Only used if iplrom.dat and iplrom30.dat are not found.
+    source_ref: "libretro.c:851"
+
+  - name: "iplromxv.dat"
+    path: "keropi/iplromxv.dat"
+    size: 131072
+    required: false
+    note: >
+      X68000 XVI IPL ROM. Last fallback in the IPL search order.
+      Only used if the three other IPL variants are not found.
+    source_ref: "libretro.c:851"
+
+  # Font ROM -- character generator ROM for text rendering.
+
+  - name: "cgrom.dat"
+    path: "keropi/cgrom.dat"
+    size: 786432
+    required: true
+    note: >
+      X68000 character generator ROM. 768 KB, provides the font glyphs for text
+      display. If missing, the core falls back to cgrom.tmp (user-generated font
+      cache). Core fails to start if neither file exists.
+    source_ref: "libretro.c:853, libretro.c:881-891"
+
+  - name: "cgrom.tmp"
+    path: "keropi/cgrom.tmp"
+    size: 786432
+    required: false
+    note: >
+      Alternative font file, used as fallback when cgrom.dat is absent.
+      Typically a font cache generated by the emulator itself on other platforms.
+    source_ref: "libretro.c:854, libretro.c:884-888"
+
+notes:
+  subdirectory: >
+    All files must be placed in <system_dir>/keropi/ subdirectory. The core sets
+    this path at init via sprintf(retro_system_conf, "%s/keropi", system_dir) and
+    then calls file_setcd() to make it the base for all file_open_c() calls.
+  ipl_selection: >
+    The four IPL ROM variants correspond to different X68000 hardware revisions.
+    The core uses whichever it finds first in order: iplrom.dat (original X68000),
+    iplrom30.dat (X68030), iplromco.dat (Compact), iplromxv.dat (XVI). Most users
+    only need iplrom.dat. The IPL also determines SASI vs SCSI disk support based
+    on vectors found at offsets 0x30600-0x30c00.
+  sram: >
+    sram.dat (16 KB) is read/write runtime state, not a BIOS file. The core creates
+    it automatically on first shutdown. It stores X68000 NVRAM settings (boot count,
+    boot device preferences, SRAM-resident programs).