Skip to content
RetroBIOS

Atari800

Atari800 emulates Atari 400-800, Atari 5200 and Atari XEGS. It reads 19 files, none of them required: it starts games without them.

About this profile
Detail Value
Type standalone + libretro
Classification Official port
Source https://github.com/libretro/libretro-atari800
Upstream https://github.com/atari800/atari800
Version 7.0.0, stated in libretro/config.h
Revision libretro/libretro-atari800@4e7fbc73765c, atari800/atari800@98cc2dc74986
Profiled 2026-03-23
Profile YAML, JSON
Cores atari800
Systems Atari 400-800, Atari 5200, Atari XEGS
Install this emulator's files

For Atari800 inside RetroArch, Batocera or another setup. 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 atari800

Files

Section titled “Files”

19 files: 0 required, 19 optional. 18 have an HLE fallback.

In this collection: 19 in repo and 0 missing.

Optional

Section titled “Optional”
FileStatusHash

5200.rom

  • Aliases: atari5200.rom, atar5200.rom, 5200.bin, atari_5200.rom
  • Atari 5200 BIOS (original). Mapped at $F800-$FFFF. Altirra 5200 OS is used when this file is absent.
Hashes, validation and source
in repo HLE fallbackMD5 281f20ea4320

atari-5200-os-2port.rom

  • Aliases: ROM_5200_A
  • Atari 5200 OS rev A, from the 2-port 5200. Any file name: every file of the system directory of 2048 bytes whose CRC32 is c2ba2613 is taken as SYSROM_5200A, and the automatic choice for the 5200 tries it after the original OS and before the Altirra 5200 OS. ROM_5200_A is the configuration key this ROM is stored under in .atari800.cfg.
Hashes, validation and source
in repo HLE fallbackCRC32 c2ba2613

ATARIBAS.ROM

  • Aliases: ataribasic.rom, basic.rom, atari_basic.rom
  • Atari BASIC Rev C. Required for 400/800 software that needs BASIC. Altirra BASIC is used as fallback. Enable via core option atari800_opt2.
Hashes, validation and source
in repo HLE fallbackMD5 0bac0c6a5010

ATARIOSA.ROM

  • Aliases: atari_osa.rom, atari_os_a.rom
  • Atari 400/800 OS Rev A. Altirra OS 800 is used as fallback. Auto-select order: OS B NTSC, OS A NTSC, OS A PAL, custom, Altirra.
Hashes, validation and source
in repo HLE fallbackMD5 eb1f32f5d9f3

ATARIOSB.ROM

  • Aliases: atari_osb.rom, atari_os_b.rom
  • Atari 400/800 OS Rev B (NTSC). CRC32 0x0e86d61d matches sysrom.c SYSROM_B_NTSC. Preferred over Rev A for 400/800 mode. Note: .info lists md5 a3e8d617c95d08031fe1b20d541434b2 which is a different dump (crc32 3e28a1fe) -- both in repo, the CRC32-matched version is the one sysrom.c auto-detects.
Hashes, validation and source
in repo HLE fallbackMD5 4177f386a3ba

ATARIXL.ROM

  • Aliases: atarixlxe.rom, atari_xlxe.rom, atari_xl_xe.rom
  • Atari XL/XE OS. Used for 800XL, 130XE, and XEGS modes. Altirra XL OS is used as fallback.
Hashes, validation and source
in repo HLE fallbackMD5 06daac977823

BB01R4_OS.ROM

  • Atari XEGS OS Rev 4 (BB01R4). Preferred OS for XEGS machine mode.
Hashes, validation and source
  • MD5: b7a2a04677d34f069eeb643d5238bf86
  • CRC32: 1eaf4002
  • Validation: size, crc32
  • Asked for by: emulator code, libretro port
  • Source: atari800/src/sysrom.c:100 (emulator code, libretro port)
in repo HLE fallbackMD5 b7a2a04677d3

XEGAME.ROM

  • XEGS built-in Missile Command ROM. Only used in XEGS machine mode. No built-in replacement exists for this ROM.
Hashes, validation and source
  • MD5: d7eb37aec6960cba36bc500e0e5d00bc
  • CRC32: bdca01fb
  • Validation: size, crc32
  • Asked for by: emulator code, libretro port
  • Source: atari800/src/sysrom.c:108 (emulator code, libretro port)
in repoMD5 d7eb37aec696

atari-800-os-a-ntsc.rom

  • Aliases: ROM_OS_A_NTSC
  • Atari 400/800 OS rev A, NTSC (SYSROM_A_NTSC). Any file name: a file of the system directory of 10240 bytes whose CRC32 is c1b3bb02 is taken for this slot. ROM_OS_A_NTSC is the configuration key this ROM is stored under in .atari800.cfg.
Hashes, validation and source
in repo HLE fallbackMD5 a3c1585b5d19

atari-1200xl-os-rev-10.rom

  • Aliases: ROM_OS_AA00R10
  • Atari 1200XL OS rev 10 (SYSROM_AA00R10). Any file name: a file of the system directory of 16384 bytes whose CRC32 is c5c11546 is taken for this slot. ROM_OS_AA00R10 is the configuration key this ROM is stored under in .atari800.cfg.
Hashes, validation and source
in repo HLE fallbackMD5 e3e8c74bfe1d

atari-1200xl-os-rev-11.rom

  • Aliases: ROM_OS_AA00R11
  • Atari 1200XL OS rev 11 (SYSROM_AA01R11). Any file name: a file of the system directory of 16384 bytes whose CRC32 is 1a1d7b1b is taken for this slot. ROM_OS_AA00R11 is the configuration key this ROM is stored under in .atari800.cfg.
Hashes, validation and source
in repo HLE fallbackMD5 eacb8069c45e

atari-xl-os-ver-1.rom

  • Aliases: ROM_OS_BB00R1
  • Atari 600XL OS (SYSROM_BB00R1). Any file name: a file of the system directory of 16384 bytes whose CRC32 is 643bcc98 is taken for this slot. ROM_OS_BB00R1 is the configuration key this ROM is stored under in .atari800.cfg.
Hashes, validation and source
in repo HLE fallbackMD5 9aea45e724d2

ROM_OS_BB02R3V4

  • Atari XL/XE OS BB02R3V4 (SYSROM_BB02R3V4). Any file name: a file of the system directory of 16384 bytes whose CRC32 is d425a9cf is taken for this slot. The name is the configuration key this ROM is stored under in .atari800.cfg.
Hashes, validation and source
in repo HLE fallbackMD5 9f5449c88147

ROM_OS_CC01R4

  • Atari XL/XE OS CC01R4 (SYSROM_CC01R4). Any file name: a file of the system directory of 16384 bytes whose CRC32 is 0e000b99 is taken for this slot. The name is the configuration key this ROM is stored under in .atari800.cfg.
Hashes, validation and source
in repo HLE fallbackMD5 65020266380e

atari-xl-os-ver-3.rom

  • Aliases: ROM_OS_BB01R3
  • Atari 65XE/130XE OS (SYSROM_BB01R3). Any file name: a file of the system directory of 16384 bytes whose CRC32 is 29f133f7 is taken for this slot. ROM_OS_BB01R3 is the configuration key this ROM is stored under in .atari800.cfg.
Hashes, validation and source
in repo HLE fallbackMD5 54e704558a6a

ROM_OS_BB01R59

  • Atari XL/XE OS BB01R59 (SYSROM_BB01R59). Any file name: a file of the system directory of 16384 bytes whose CRC32 is 45f47988 is taken for this slot. The name is the configuration key this ROM is stored under in .atari800.cfg.
Hashes, validation and source
in repo HLE fallbackMD5 d467f55fb764

ROM_OS_BB01R59A

  • Atari XL/XE OS BB01R59A (SYSROM_BB01R59A). Any file name: a file of the system directory of 16384 bytes whose CRC32 is f0a236d3 is taken for this slot. The name is the configuration key this ROM is stored under in .atari800.cfg.
Hashes, validation and source
in repo HLE fallbackMD5 69396860e53f

atari-basic-rev-a.rom

  • Aliases: ROM_BASIC_A
  • Atari BASIC rev A (SYSROM_BASIC_A). Any file name: a file of the system directory of 8192 bytes whose CRC32 is 4bec4de2 is taken for this slot. ROM_BASIC_A is the configuration key this ROM is stored under in .atari800.cfg.
Hashes, validation and source
in repo HLE fallbackMD5 a4dc52536d52

atari-basic-rev-b.rom

  • Aliases: ROM_BASIC_B
  • Atari BASIC rev B (SYSROM_BASIC_B). Any file name: a file of the system directory of 8192 bytes whose CRC32 is f0202fb3 is taken for this slot. ROM_BASIC_B is the configuration key this ROM is stored under in .atari800.cfg.
Hashes, validation and source
in repo HLE fallbackMD5 04ea6a4e3866

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.