Skip to content
RetroBIOS

Flycast 2022 Low-End

Flycast 2022 Low-End emulates Sega Dreamcast, Sega NAOMI and Sammy Atomiswave. It reads 8 files, 5 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 Enhanced fork
Source https://github.com/navy1978/flycast2022-lowend
Upstream https://github.com/libretro/parallel-dc
Version 0.1
Revision navy1978/flycast2022-lowend@bf93aece5db7, libretro/parallel-dc@4c293f306bc1
Built by amberelec, under its core name. The libretro buildbot does not publish this build.
Revision held AmberELEC, the only platform that ships it, builds this revision (AmberELEC packages/games/libretro/flycast2021le/package.mk:5). Later commits are not part of that build.
Profiled 2026-10-22
Profile YAML, JSON
Cores flycast2021le
Systems Sega Dreamcast, Sega NAOMI, Sammy Atomiswave
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 a terminal on the device. Or connect from a computer with SSH, a terminal over the network. Paste the line. Press Enter.

Terminal
curl -fsSL https://raw.githubusercontent.com/Abdess/retrobios/main/install.sh | sh -s -- --emulator flycast2021le
Technical notes

The libretro/flycast tree of 6 April 2022 (4c293f30, the repository now answers as libretro/parallel-dc) with 21 commits by navy1978 on top that add optional CPU, renderer and audio paths for RK3326/RK3566 handhelds. None of them touches the code that opens system files. AmberELEC builds this revision, renames the core option prefix from reicast to flycast2021le and installs the library as flycast2021le_libretro.so. ref: AmberELEC packages/games/libretro/flycast2021le/package.mk:5,19,50

Every system file lives in <system>/dc/. ref: core/libretro/libretro.cpp:2189-2193

Dreamcast: the boot ROM is looked for as dc_boot.bin, dc_boot.bin.bin, dc_bios.bin, dc_bios.bin.bin, the first that yields a full 2 MB read wins. The HLE BIOS core option defaults to disabled. When no boot ROM loads, reios boots the disc instead. Booting to the BIOS menu, or starting without a disc, needs the real boot ROM and fails with -3 without it. ref: core/hw/holly/sb_mem.cpp:51-65, core/hw/holly/sb_mem.cpp:215-233, core/hw/flashrom/flashrom.h:54-67, core/hw/flashrom/flashrom.h:84-118, core/nullDC.cpp:420-431, core/nullDC.cpp:455-463, core/libretro/libretro_core_options.h:226-239, core/libretro/libretro.cpp:885-890

NAOMI and Atomiswave: a BIOS archive is opened as <system>/dc/<name> with .7z then .zip appended. Each member is looked for in the game archive, its parent, then the BIOS archive, by CRC32 and then by name. The BIOS table carries no CRC32, so only the name matches. The member for the configured region is tried first, then the first member listed. A game whose table entry names a BIOS refuses to start without it, and the others default to naomi. Five archive names are reachable from the game table: naomi, awbios, f355bios, f355dlx, hod2bios. airlbios and naomigd have table entries but no game names them. ref: core/hw/naomi/naomi_cart.cpp:77-180, core/hw/naomi/naomi_cart.cpp:227-247, core/archive/archive.cpp:26-42, core/hw/naomi/naomi_roms.h:76-213

LoadRomFiles also reads naomi_boot.bin, naomi_boot.bin.bin, naomi_bios.bin, naomi_bios.bin.bin and epr-21576d.bin for NAOMI, but naomi_cart_LoadRom calls naomi_cart_Close, which clears bios_loaded, before the cartridge loads, so that file never stands in for naomi.zip. ref: core/hw/holly/sb_mem.cpp:59, core/nullDC.cpp:432-435, core/nullDC.cpp:77-81, core/hw/naomi/naomi_cart.cpp:427-450, core/hw/naomi/naomi_cart.cpp:473-485

Files

Section titled “Files”

8 files: 5 required, 3 optional. 1 has an HLE fallback.

By kind: 3 BIOS and 5 BIOS ZIPs.

File Required
dc/naomi.zip for Sega NAOMI
dc/awbios.zip for Sammy Atomiswave
dc/f355bios.zip for Sega NAOMI
dc/f355dlx.zip for Sega NAOMI
dc/hod2bios.zip for Sega NAOMI
dc/dc_boot.bin no
dc/dc_nvmem.bin no
dc/font.bin no

In this collection: 8 in repo and 0 missing.

Required

Section titled “Required”

naomi.zip required for Sega NAOMI in repo BIOS ZIP

NAOMI BIOS archive

  • Default BIOS of every NAOMI game whose table entry names none, cartridge, .lst, .bin and .dat images alike. One member is loaded: the one for the configured region, else epr-21576h.ic27.
  • Contents (4 members):
    • epr-21576h.ic27: Japan, 2.0 MB
    • epr-21578h.ic27: Export, 2.0 MB
    • epr-21577h.ic27: USA, 2.0 MB
    • epr-21579d.ic27: Korea, 2.0 MB

awbios.zip required for Sammy Atomiswave in repo BIOS ZIP

Atomiswave BIOS archive

  • Named by all 34 Atomiswave games. Loaded into the flash chip, whose writable part is then reloaded from the save directory.
  • Contents (1 members):
    • bios0.ic23: 128.0 KB

f355bios.zip required for Sega NAOMI in repo BIOS ZIP

Ferrari F355 Challenge BIOS archive

  • Named by three Ferrari F355 Challenge entries, which refuse to start without it.
  • Contents (3 members):
    • epr-22851.ic27: Export, 2.0 MB
    • epr-22850.ic27: USA, 2.0 MB
    • epr-22849.ic27: Japan, 2.0 MB

f355dlx.zip required for Sega NAOMI in repo BIOS ZIP

Ferrari F355 Challenge Deluxe BIOS archive

  • Named by the f355 entry, which refuses to start without it.
  • Contents (3 members):
    • epr-21864.ic27: Export, 2.0 MB
    • epr-21863.ic27: USA, 2.0 MB
    • epr-21862.ic27: Japan, 2.0 MB

hod2bios.zip required for Sega NAOMI in repo BIOS ZIP

The House of the Dead 2 BIOS archive

  • Named by four House of the Dead 2 entries, which refuse to start without it.
  • Contents (3 members):
    • epr-21331.ic27: Export, 2.0 MB
    • epr-21330.ic27: USA, 2.0 MB
    • epr-21329.ic27: Japan, 2.0 MB

Optional

Section titled “Optional”
3 files

dc_boot.bin optional in repo HLE fallback

Dreamcast boot ROM

  • Size: min 2.0 MB
  • Aliases: dc_boot.bin.bin, dc_bios.bin, dc_bios.bin.bin
  • Read as 2 MB into the system ROM, and a shorter file is rejected. Needed only to boot to the BIOS menu or to start without a disc.

dc_nvmem.bin optional in repo

Dreamcast flash ROM

  • Size: min 128.0 KB
  • Aliases: dc_flash_wb.bin, dc_flash.bin, dc_flash.bin.bin
  • Loaded with the boot ROM and by the HLE path. A missing file leaves the flash blank and the core runs. Written back as dc_nvmem.bin.

font.bin optional in repo

Dreamcast system font for the HLE BIOS

  • Read whole into the font table of the reios ROM image. Absent, a built-in font is copied there.

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.