emulator: Sonic 1 & 2 (2013) Decompilation
type: standalone
core_classification: game_engine
source: "https://github.com/Rubberduckycooly/Sonic-1-2-2013-Decompilation"
upstream: "https://github.com/Rubberduckycooly/Sonic-1-2-2013-Decompilation"
source_commit: "a7f5195e21fdad7b75e4587e249013feeea9e6f3"
core_version: "1.3.3"
profiled_date: "2026-10-04"
display_name: "Sonic 1 & 2 (2013) (RSDKv4 Decomp)"
cores: []
systems: [sonic-1-2013, sonic-2-2013]

notes: |
  Shared Retro Engine v4 decompilation driving the 2013 Christian Whitehead
  mobile ports of Sonic the Hedgehog and Sonic the Hedgehog 2. One binary
  per build; the game identity is derived from the GameConfig.bin inside
  the loaded data pack (gameWindowText "Sonic 1" or "Sonic 2").
  ref: RSDKv4/RetroEngine.cpp:423, RSDKv4/ModAPI.cpp:428

  CheckRSDKFile just fopen()s the data pack; there is no signature or
  checksum test. The engine falls back to a loose Data/ + Bytecode/ tree
  if the pack is absent, and writes a usage.txt that asks for a pack named
  Engine.dataFile[0] (default "Data.rsdk").
  ref: RSDKv4/RetroEngine.cpp:296-331, RSDKv4/Userdata.cpp:251-263,
       RSDKv4/RetroEngine.cpp:484-521

  Up to four packs can be mounted (DataFile, DataFile2..4 in the Dev
  section of settings.ini); the extras default to Data2.rsdk, Data3.rsdk,
  Data4.rsdk once declared.
  ref: RSDKv4/RetroEngine.hpp:373, RSDKv4/Userdata.cpp:396-408

files:
  - name: "Data.rsdk"
    category: game_data
    system: sonic-1-2013
    required: true
    source_ref: "RSDKv4/RetroEngine.cpp:321 (CheckRSDKFile(\"Data.rsdk\")), RSDKv4/Userdata.cpp:252"
    note: |
      Sonic the Hedgehog (2013) assets. Shipped with the official Sonic
      Origins release and the delisted iOS/Android apps. Engine opens the
      file with fopen(); content identity is read from the embedded
      GameConfig.bin, not the pack hash.

  - name: "Data.rsdk"
    category: game_data
    system: sonic-2-2013
    required: true
    source_ref: "RSDKv4/RetroEngine.cpp:321 (CheckRSDKFile(\"Data.rsdk\")), RSDKv4/Userdata.cpp:252"
    note: |
      Sonic the Hedgehog 2 (2013) assets. Shipped with the official Sonic
      Origins release and the delisted iOS/Android apps. Same engine
      filename as Sonic 1; the launcher selects which pack sits next to
      the binary at run time.