¶ Technical data
- Manufacturer: Nintendo
- Year of release: February 1986 (Japan only)
- Host machine: Family Computer (Famicom), through a RAM adapter inserted in the cartridge slot
- Media: 2.8-inch double-sided Quick Disk, roughly 112 KB in total
- Sound: an extra wave-modulation synthesis channel, on top of the Famicom's 5 channels
- Storage: saves written directly to the disk
¶ Presentation
The Family Computer Disk System, or Famicom Disk System, is a peripheral launched by Nintendo in Japan in February 1986. It consists of a disk drive and a RAM adapter that takes the place of a cartridge in the Famicom. Its medium, a 2.8-inch Quick Disk developed by Mitsumi, offers roughly 112 KB spread over two sides — far more than a cartridge of the time, and at a much lower manufacturing cost.
The Disk System brought three decisive advantages for its era: greater storage capacity, the ability to save progress directly onto the disk (before battery-backed cartridges became common), and an extra sound channel using wave modulation that noticeably enriched the music. Nintendo also installed Disk Writer kiosks in Japanese shops: for a few hundred yen, a disk could be rewritten with another game.
This is the medium on which The Legend of Zelda, Metroid, Kid Icarus, Castlevania and Doki Doki Panic (which became Super Mario Bros. 2 in the West) first appeared. Success was short-lived, though: falling cartridge prices, their growing capacity and the fragility of unprotected disks did the peripheral in. It remained exclusive to Japan and production stopped in the early 1990s. Most of its games were later re-released on cartridge.
¶ Emulators
Emulator availability per board:
| Emulator | RPI3/RPI02W | RPI4/400 | RPI5/500 | OGA/OGS/RG351 | PC | RG353 |
|---|---|---|---|---|---|---|
| Libretro nestopia | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
| Libretro fceumm | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
| Libretro mesen | ❌ | ✅ | ✅ | ✅ | ✅ | ✅ |
| Libretro fbneo | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
Mesen is not available on RPi3 and RPi Zero 2. The three other cores are present on all boards.
Nestopia is the default emulator. FCEUmm comes second and remains the most forgiving core with unusual dumps; it is also the only one supporting softpatching on this system. Mesen is the most accurate, in particular for emulating the Disk System's extra sound channel, but also the most demanding. FBNeo only reads zipped romsets.
Netplay is available with all four cores. CRT output is supported by Nestopia and FCEUmm. RetroAchievements are not available on this system. A controller is mandatory.
¶ BIOS
The Disk System BIOS is mandatory: without it, no game will start.
| File name | Description | MD5 | Emulators |
|---|---|---|---|
disksys.rom |
Family Computer Disk System BIOS (mandatory) | ca30b50f880eb660a320674ed365ef7a | FCEUmm, Nestopia, Mesen |
Place the BIOS like this:
/recalbox/share/bios/fds/
└── disksys.rom
If your games show a black screen or hang at startup, it is almost always because
disksys.romis missing, misnamed or in the wrong place. Check the file's MD5.
¶ Roms
Put your games in:
/recalbox/share/roms/fds/
Supported extensions per emulator:
| Emulator | Extensions |
|---|---|
| Nestopia | .fds .zip .7z |
| FCEUmm | .fds .zip .7z |
| Mesen | .fds .zip .7z |
| FBNeo | .zip .7z |
The standard format is .fds. A No-Intro romset is strongly recommended: its dumps are normalised and usually gather every side of a given game into a single file.
Disk System games use double-sided disks, and some titles span several disks. When a game asks you to flip the disk or to insert the next one, use RetroArch's disc control: open the RetroArch menu, go to the disc submenu, eject, select the wanted index then re-insert.
Also have a look at the Family Computer Disk System guide for game preparation, configuration and system-specific tips.