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RetroBIOS

RustyNES

RustyNES emulates Nintendo NES and Nintendo Famicom Disk System. It reads 1 file, 1 of them required: without a required file it does not start games. A required file is needed only by the machines that use it. Each file below cites the line of source code that reads it.

About this profile
Detail Value
Type libretro
Classification Official port
Source https://github.com/doublegate/RustyNES
Version 3.5.0, stated in Cargo.toml
Revision doublegate/RustyNES@3d02b99dc84f
Profiled 2026-10-26
Profile YAML, JSON
Cores rustynes
Systems Nintendo NES, Nintendo Famicom Disk System
Install this emulator's files

The installer finds your setup and its BIOS folder, then downloads only the files this emulator reads there and checks each one.

Open the Start menu. Type PowerShell and open it. Paste the line. Press Enter.

PowerShell
&([scriptblock]::Create((irm https://abdess.github.io/retrobios/i.ps1))) --emulator rustynes
Technical notes

RustyNES is a NES and Famicom emulator written in Rust by DoubleGate. The libretro core is the crates/rustynes-libretro crate of the same repository, built from the main branch (crates/rustynes-libretro/Makefile, .gitlab-ci.yml). The crate pulls rustynes-core with default features off and does not link the rustynes-hdpack crate, so no HD pack is read. The game database it links is compiled in (crates/rustynes-gamedb/src/lib.rs:41), and its game_db_user.txt overlay is read only once a host sets its directory, which the libretro crate never does (crates/rustynes-gamedb/src/lib.rs:356-366).

Cartridge content needs no external file. Content is a Famicom Disk System image when its path ends in .fds or its bytes open with the fwNES header or the NINTENDO-HVC side marker (crates/rustynes-libretro/src/lib.rs:2225-2244). Such an image goes to Nes::from_disk, which needs the Famicom Disk System BIOS: the core joins disksys.rom to the frontend system directory and reads the whole file (crates/rustynes-libretro/src/lib.rs:1380-1396). A missing file, or a frontend without a system directory, makes retro_load_game fail with an error. Fds::new rejects a BIOS that is not exactly 8192 bytes (crates/rustynes-mappers/src/fds.rs:1368-1374). No hash is checked. The FDS device maps the BIOS and boots from its reset vector.

The version comes from the workspace Cargo.toml. The .info in libretro-core-info says v3.4.0 and the copy in the repository v3.5.0. The md5 in the .info notes is not enforced by the code.

Files

Section titled “Files”

1 file: 1 required, 0 optional.

In this collection: 1 in repo and 0 missing.

Required

Section titled “Required”

disksys.rom required for Nintendo Famicom Disk System in repo

Famicom Disk System BIOS

  • System: Nintendo Famicom Disk System
  • Read only when the content is a Famicom Disk System image, by extension or signature. Any other size fails the load.
Validation and source

Next steps

Section titled “Next steps”
.

Maintained by Abdess on GitHub. Report a problem.

Packs from release v2026.10.10, .

MIT for the tooling and metadata. BIOS and firmware files are third-party system software, preserved for personal backup, archival and interoperability.