emulator: Mini vMac
type: libretro
source: "https://github.com/libretro/libretro-minivmac"
profiled_date: "2026-03-18"
core_version: "GIT"
display_name: "Mac II (minivmac)"
systems: [macintosh-ii]

# Mini vMac is a Macintosh II emulator. The libretro port is hardcoded for
# Mac II emulation (CurEmMd = kEmMd_II) with 68020 CPU, FPU, ADB, VIA2, ASC.
# ROM is loaded from the RetroArch system directory.

# ROM loading order (OSGLUERETRO.c LoadMacRom):
#   1. <system>/MacIIx.ROM    (tried first, same 256 KB size)
#   2. <system>/MacII.ROM     (defined as RomFileName in CNFGRAPI.h)
#   3. --rom command line arg  (if provided)
#   4. ~/.gryphel/mnvm_rom/MacII.ROM
#   5. app parent directory
#   6. current directory

# ROM size: kROM_Size = 0x00040000 = 262144 bytes (256 KB)
# ROM checksums defined in CNFGRAPI.h:
#   kRomCheckSum1 = 0x9779D2C4 (Mac II v1)
#   kRomCheckSum2 = 0x97221136 (Mac II v2)
# Note: DisableRomCheck = 1, so checksum validation is skipped at runtime
# (ROMEMDEV.c patches the ROM check jump). Any 256 KB Mac II ROM works.

files:
  # -- MacII.ROM (primary, required) --
  # Standard Macintosh II ROM image. This is the hardcoded RomFileName.
  # The core reads exactly kROM_Size (262144) bytes from this file.

  - name: "MacII.ROM"
    path: "MacII.ROM"
    required: true
    size: 262144
    source_ref: "minivmac/cfg/CNFGRAPI.h:32, minivmac/src/OSGLUERETRO.c:781"
    note: >
      Macintosh II ROM image (256 KB). The core loads this from the system
      directory. Must be exactly 262144 bytes. ROM checksum verification is
      disabled in the libretro build, so either Mac II ROM revision works.

  # -- MacIIx.ROM (alternative, optional) --
  # Tried before MacII.ROM in the loading sequence. The Mac IIx ROM is the
  # same 256 KB size and is compatible with the Mac II emulation mode.

  - name: "MacIIx.ROM"
    path: "MacIIx.ROM"
    required: false
    size: 262144
    source_ref: "minivmac/src/OSGLUERETRO.c:778"
    note: >
      Macintosh IIx ROM image (256 KB). Checked first in the ROM loading
      sequence. If present, it takes priority over MacII.ROM. The Mac IIx
      uses the same 68020-class architecture as the Mac II.

notes:
  emulation_target: >
    The libretro build is configured exclusively for Macintosh II emulation
    (kEmMd_II). Build options: 68020 CPU, FPU enabled, ADB keyboard/mouse,
    VIA2, ASC sound chip. Screen: 640x480, 8-bit color depth.
  disk_formats: >
    Supported disk image formats: .dsk, .img, .zip, .hvf, .cmd
    The core auto-inserts the loaded content as a floppy disk.
    Supports up to NumDrives simultaneous disk images.
  rom_checksum_note: >
    DisableRomCheck is set to 1 in ROMEMDEV.c, meaning the core patches out
    the ROM checksum verification at boot. This allows any valid Mac II era
    ROM to work regardless of exact revision.