Doom was released on 10 December 1993 by id Software, as MS-DOS shareware. Programmed by John Carmack around an engine that would later become known as id Tech 1, and designed by John Romero, Sandy Petersen and Tom Hall, it drops a nameless space marine into a Martian base overrun by demons. Dark corridors, secrets everywhere, a chainsaw and a BFG: the game invented much of the modern FPS vocabulary and popularised networked deathmatch.
Doom was above all the first great modding machine. Its game data — levels, textures, sounds, music — is packed into WAD files (Where's All the Data), a documented format the community started bending as early as 1994 to build levels, then entire campaigns. Thirty years on, the Doom scene still publishes dozens of megawads every year.
On 23 December 1997, id Software released the engine source code under the GPL. Dozens of source ports followed. Recalbox uses PrBoom, a direct descendant of Boom (TeamTNT, 1998): a conservative port, very faithful to the original behaviour, compatible with the vast majority of the scene's WADs and light enough to run on any machine.
| Studio | id Software |
| Year of release | 1993 |
| Engine | id Tech 1 (Doom engine), replayed by PrBoom |
| Game type | FPS |
| Port licence | GPL-2.0 |
| Controller | Mandatory |
Recalbox ships two games already installed on this system: the shareware version of DOOM and the SIGIL megawad. See the Included games page.
Emulator availability per board:
| Emulator | RPI3/RPI02W | RPI4/400 | RPI5/500 | OGA/OGS/RG351 | PC | RG353 |
|---|---|---|---|---|---|---|
| Libretro prboom | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
PrBoom is the only emulator for this system and is therefore used by default on every machine, including the Raspberry Pi Zero 2. Netplay is not available on this system and RetroAchievements are not supported. CRT output is handled by the core.
Recalbox automatically installs the core's resource file in
/recalbox/share/bios/prboom/prboom.wad. It is not a BIOS and there is nothing for you to add there, but do not delete it: the core needs it to start.
PrBoom contains no game data at all: it reads .wad files. There are two families:
doom.wad (Doom / The Ultimate Doom), doom2.wad (Doom II), tnt.wad and plutonia.wad (Final Doom), or the fully free IWADs freedoom1.wad / freedoom2.wad;Adding a commercial game from the Doom family therefore comes down to dropping its .wad into the roms folder, next to the ones already there. No installation, no configuration.
PrBoom replays Doom engine games: Doom, The Ultimate Doom, Doom II, Final Doom, Freedoom and the scene's huge catalogue of megawads. The Raven games (Heretic, Hexen) and Strife run on derived engines and are not supported by this core.
SIGIL is a megawad by John Romero, co-founder of id Software and author of a large part of the 1993 Doom levels. Released on 1 May 2019 for the game's twenty-fifth anniversary, it is designed as an unofficial fifth episode for The Ultimate Doom: nine single-player levels plus nine deathmatch maps, deliberately harsh and maze-like, picking up where episode 4 ends. Recalbox ships version 1.21, as the file SIGIL_v1_21.wad.
SIGIL is not a separate system: it is a Doom PWAD, shipped and launched by the prboom core of the
doomsystem, exactly like any other megawad.
Like every PWAD, SIGIL is layered on top of an IWAD. It was designed for the complete The Ultimate Doom IWAD (all four episodes), which is where it shows its full potential. If you own the commercial game, simply replace the shareware doom.wad in the roms folder with your own.
Put your games in:
/recalbox/share/roms/ports/Doom/
Supported extensions: .wad .iwad .pwad .lmp .zip .7z
The folder shipped by Recalbox looks like this:
/recalbox/share/roms/ports/Doom/
├── doom.wad ← shareware IWAD (episode 1, Knee-Deep in the Dead)
├── SIGIL_v1_21.wad ← John Romero's megawad
├── Doom (Shareware)/
│ └── license.txt
├── Sigil (John Romero)/
│ ├── SIGIL_instructions.txt
│ └── SIGIL_v1_21.txt
└── game-musics/
To add a game, copy its .wad straight into the root of that folder, then refresh the game lists from the menu. .lmp files are recorded demos (games replayed automatically by the engine). .zip and .7z archives are accepted, but each one must contain exactly one file.
The game-musics/ folder is meant for replacing the soundtrack with your own MP3 files: the _readme.txt it contains explains the mus_e1m1, mus_e1m2… lines to add to the core's prboom.cfg.
This system is read-write: you can add and remove files freely. However, the files shipped by Recalbox are copied again on every version upgrade. If you delete
doom.wadorSIGIL_v1_21.wad, they will reappear after the next update.