Abdessamad Derraz
6353ee53df
Five tabs from Start here to Contribute, a level on every page, a device picker on Get your files that lists every registered platform, and platform pages that open on where the files go, the command, the pack and how to check. FAQ and troubleshooting keep the questions asked before installing, the technical ones move to their own page, and getting started points to the pages that took its content.
2.9 KiB
level
| level |
|---|
| start |
What BIOS files are
Many consoles have a small program built into them. It runs when the console is switched on, sets up the hardware and then starts the game. That program is called the BIOS, or the firmware.
An emulator recreates a console in software. To start the games of many consoles, it needs a copy of that built-in program. The copy is a file, and that file is what people call a BIOS file.
How the pieces fit together
- You pick a game in the frontend, the menu you play from (EmulationStation, the RetroArch menu, MinUI and others).
- The frontend starts an emulator for that console.
- The emulator reads the BIOS file from the BIOS folder of your setup.
- The game starts.
When the file is not in the folder, or is not the version the emulator expects, step 3 fails. The emulator then says that a BIOS is missing, or the game stays on a black screen.
Do I need them?
It depends on the console.
- Usually yes for consoles that start every game through their own program: PlayStation, PlayStation 2, Saturn, Mega-CD, PC Engine CD, Neo Geo, Dreamcast, and many home computers.
- Usually not for cartridge consoles such as the NES, the Super Nintendo, the Mega Drive, the Game Boy and the Game Boy Advance. Their emulators start the games without one. Some can use one to show the original start-up screen.
- Add-ons need their own, even on those consoles: the Famicom Disk System and the Mega-CD each have a BIOS.
Some emulators can stand in for the BIOS with code of their own. This is called HLE, for high-level emulation. It works for many games, but some glitch or do not start. The real file gives the best results, so the packs include it.
Details: the files each console needs, with the emulators that read them.
Where they go
Each setup keeps its BIOS files in a folder of its own: system for RetroArch,
/userdata/bios on Batocera, Emulation/bios with EmuDeck. The page of your
setup gives the exact folder.
The name matters. An emulator looks for an exact name, such as scph5501.bin
for a PlayStation, and a file with another name is not found.
Why the right version matters
Two files with the same name can hold different versions: one per region, or a newer revision of the same chip. Some setups, among them Batocera, Recalbox and EmuDeck, compare a fingerprint of the file's contents, called a hash, and refuse a version they do not list. RetroBIOS gives each setup the versions it expects.
Is it legal?
Laws on copying console firmware differ by country, and the question is not settled. The project's position explains where it stands, where its arguments are weakest, and how to ask for a file to be removed.
!!! tip "Next"
- [Get your files](../which-pack.md), for the setup you play on
- [Glossary](glossary.md), every word these pages use