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RetroBIOS

Gearlynx

Gearlynx emulates Atari Lynx. It reads 1 file, 1 of them required: without a required file it does not start games.

About this profile
Detail Value
Type libretro
Classification Official port
Source https://github.com/drhelius/Gearlynx
Version 1.2.36-10-g77901f3, 10 commits after tag 1.2.36
Revision drhelius/Gearlynx@77901f3d3b31
Profiled 2026-10-04
Profile YAML, JSON
Cores gearlynx
Systems Atari Lynx
Checks the file by existence
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 gearlynx
Technical notes

Gearlynx is an Atari Lynx emulator by Ignacio Sanchez (drhelius). The libretro core loads lynxboot.img from the system directory in retro_load_game() and again in retro_reset() (platforms/libretro/libretro.cpp:175-217, function load_bootroms). Path is built as: system_directory + "/lynxboot.img", no subdirectory. With the libretro VFS the file is read by load_bios_file() and handed to LoadBiosFromBuffer(), otherwise Media::LoadBios() opens it (platforms/libretro/libretro.cpp:135-173, src/media.cpp:583-625).

LoadBiosData in src/media.cpp:638-688 takes exactly 512 bytes (GLYNX_BIOS_SIZE = 0x200, src/defines.h:50). If the file size is not 0x200, the load is rejected with BIOS_LOAD_INVALID_SIZE. After loading, bytes at offset 0x1F8 and 0x1F9 are patched (RAM/MAPCTL registers), then CRC32 is computed and compared against GLYNX_DB_BIOS_CRC (0x0D973C9D, src/game_db.h:47). An invalid CRC triggers a warning log but the BIOS is still marked as loaded (m_is_bios_loaded = true).

No HLE fallback. If the BIOS is not loaded (IsBiosLoaded() returns false), RunToVBlank in src/gearlynx_core.cpp:232-237 renders a static "no bios" image and returns false, refusing to emulate. The BIOS is required for any ROM to run. Homebrew (.o, BS93 format) bypasses the normal boot sequence via PrepareForHomebrew() but still requires the BIOS to be loaded for the emulation loop to execute.

ROM extensions: .lnx, .lyx, .o, .bin

Files

Section titled “Files”

1 file: 1 required, 0 optional.

In this collection: 1 in repo and 0 missing.

Required

Section titled “Required”

lynxboot.img required in repo

Atari Lynx boot ROM

  • 512-byte boot ROM validated by CRC32 after load. Invalid CRC logs a warning but still works. Missing or wrong-size file blocks emulation entirely (no HLE fallback).
Hashes, validation and source

Next steps

Section titled “Next steps”
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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.