emulator: DGen/SDL
type: standalone
core_classification: other
source: "https://sourceforge.net/p/dgen/dgen"
profiled_date: "2026-10-20"
source_commit: "1c196e63d3e35704a97a2cef60def9df3c9fd1ce"
core_version: "1.33"
display_name: "Sega - Mega Drive - Genesis (DGen/SDL)"
mode: standalone
cores:
  - dgen
systems:
  - sega-megadrive
  - sega-genesis

notes: |
  Mega Drive emulator for SDL by Joe Groff and Phil K. Hornung, carried on by
  zamaz. Release 1.33 is the v1.33 tag of the project's git tree. It emulates
  the 68000, the Z80, the VDP, the YM2612 and the SN76489 and nothing more: the
  tree holds no SH-2, no Sega CD hardware and no TMSS boot ROM.

  A cartridge is opened as given, then under the roms subdirectory of the DGen
  home ($HOME/.dgen), or under str_rom_path when the configuration sets one. It
  is unpacked through libarchive when compressed, de-interleaved when it is an
  SMD dump, and refused unless "SEGA" stands at offset 0x100.
  ref: romload.c:14-19,47-124, system.c:293-340, system.h:23-24, rc.cpp:554-560

  The only other files read are dgenrc, save states, battery RAM and demos,
  all written by the emulator itself under the DGen home.
  ref: main.cpp:132-196,352-366, system.h:45-47

exclusion_note: >
  Nothing to obtain. No BIOS or firmware is opened. The RetroPie scriptmodule
  help asks for bios_CD_U.bin, bios_CD_E.bin and bios_CD_J.bin, but no code
  path of this release names them, and a Sega CD image is refused by the
  "SEGA" header test.
  ref: romload.c:83-115

files: []