emulator: FreeIntv
type: libretro
source: "https://github.com/libretro/FreeIntv"
profiled_date: "2026-03-18"
core_version: "2018.1.5"
display_name: "Mattel - Intellivision (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.