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Atari 800

Atari 800 icon Atari 800 logo

Overview

The Atari 8-bit family (400, 800, XL, XE) debuted in 1979 with the Atari 800 as its flagship model. These machines were built around custom ANTIC/GTIA chips, a powerful ANTIC video processor and the MOS 6502 CPU, delivering advanced graphics and sound capabilities for their era. REG-Linux groups the line under atari800 so compatible themes can show the dedicated artwork set.

Technical specifications

  • Manufacturer: Atari
  • Release year: 1979
  • Hardware type: computer
  • EmulationStation group: atari8bit

Supported ROM extensions

rom, xfd, atr, atx, cdm, cas, car, bin, a52, xex, zip, 7z, m3u

Quick reference

  • Emulator/frontend: RetroArch
  • Core: libretro: atari800
  • ROM folder: /userdata/roms/atari800
  • System group: atari800

BIOS

Atari 8-bit emulation in REG-Linux relies on a handful of OS ROMs:

MD5 checksum Share file path Description
eb1f32f5d9f382db1bbfb8d7f9cb343a bios/ATARIOSA.ROM PAL OS A (1.0)
a3e8d617c95d08031fe1b20d541434b2 bios/ATARIOSB.ROM NTSC OS B (early)
4177f386a3bac989a981d3fe3388cb6c bios/ATARIOSB.ROM NTSC OS B (later)
06daac977823773a3eea3422fd26a703 bios/ATARIXL.ROM XL/XE extended ROM
0bac0c6a50104045d902df4503a4c30b bios/ATARIBAS.ROM Atari BASIC interpreter (optional but useful)

Different games may rely on a specific OS, so experiment with PAL/NTSC variants or the XL/XE ROM when compatibility issues arise.

ROMs

Place Atari 8-bit titles in /userdata/roms/atari800. The emulator supports raw disk dumps (.atr, .xfd), cartridge images, and archives/playlist formats. Multi-disk releases must be managed via the atari800 core’s UI rather than playlists; press [L3] or [F1] to access the internal menu if needed.

Emulators

RetroArch

RetroArch runs the libretro atari800 core, giving you unified hotkeys, shaders, decorations, and netplay features. Open the Quick Menu ([HOTKEY] + south button) to adjust settings or remap inputs. REG-Linux exposes system-wide hooks such as atari800.videomode, atari800.ratio, atari800.shaders, atari800.smooth, atari800.pixel_perfect, atari800.decoration, atari800.game_translation.

libretro: atari800 configuration

ES setting name REG-Linux.conf_key Description => ES option key_value
ATARI SYSTEM atari800.atari800_system Choose the machine mode (400/800, 800XL, 130XE, Modern XL/XE variations).
VIDEO STANDARD atari800.atari800_ntscpal Switch between NTSC and PAL timing and resolutions.
SIO ACCELERATION atari800.atari800_sioaccel Speed up disk/tape loading (may break some titles).
HI-RES ARTIFACTING atari800.atari800_artifacting Emulate NTSC artifact colors for hi-res graphics.
INTERNAL RESOLUTION atari800.atari800_resolution Select an alternate rendering resolution.
JOYSTICK HACK atari5200.atari800_opt2 Treat the second analog stick as joystick 2 (useful for Robotron style titles).

Many settings (cartridge type, keyboard layouts, disk selection) can be edited inside the atari800 core UI when a game is running.

Controls

The default Atari 8-bit pad mapping appears on a REG-Linux Retropad:

atari800

Use RetroArch’s Quick Menu or the atari800 menu to remap buttons or tweak analog controls.

Troubleshooting

My game looks wrong or boots in black & white

Enable NTSC timing and HI-RES ARTIFACTING in the core options. Some titles rely on NTSC artifact colors to show more than two colors on screen.

Game refuses to load; there is no prompt

Open the atari800 internal menu ([L3] or [F1]) and choose the correct format (disk, cartridge, tape). Check the core’s documentation for the expected keypresses for .atr, .xfd and .car files.

Further troubleshooting

  • Ensure BIOS files match the MD5 hashes listed above.
  • Confirm ROMs are stored under /userdata/roms/atari800 and the loader is pointed at the right file.