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Atari 7800

Atari 7800 icon Atari 7800 logo

Overview

The Atari 7800 ProSystem, released in 1986, was designed as a high-end follow-up to the Atari 2600 with improved graphics, sound and backwards compatibility with most 2600 cartridges. It introduced a digital signature scheme to curb low-quality unlicensed releases in the wake of the 1983 crash while supporting more ambitious home arcade conversions.

REG-Linux treats the system as atari7800 so compatible themes can surface the dedicated artwork set and metadata.

Technical specifications

  • Manufacturer: Atari
  • Release year: 1986
  • Hardware type: console
  • CPU: Ricoh 65c02 at 1.79 MHz
  • Graphics: MARIA video processor (160×240, 256 colours, hardware sprites/objects)
  • Sound: TIA-compatible audio with stereo outputs plus PWM control

Supported ROM extensions

a78, bin, zip, 7z

Quick reference

  • Emulator/frontend: RetroArch
  • Core: libretro: ProSystem
  • ROM folder: /userdata/roms/atari7800
  • System group: atari7800

BIOS

The system can run without explicit BIOS files. The optional Atari 7800 BIOS (bios/7800 BIOS (U).rom) can be placed in your BIOS folder if you prefer to match retail behaviour, but it is not mandatory.

ROMs

Place Atari 7800 dumps in /userdata/roms/atari7800. RetroArch handles raw .a78/.bin files and archives such as .zip or .7z that contain one or more games.

Emulators

RetroArch

RetroArch hosts libretro: ProSystem, offering unified hotkeys, shaders, overlays and input mappings across cores. Open the Quick Menu with [HOTKEY] + south button to tweak settings or per-game controls, or use EmulationStation menus for the most common options.

RetroArch configuration

Standardized features available to all libretro cores in this system include atari7800.videomode, atari7800.ratio, atari7800.smooth, atari7800.shaders, atari7800.pixel_perfect, atari7800.decoration and atari7800.game_translation.

ES setting name REG-Linux.conf_key Description => ES option key_value
GRAPHICS API atari7800.gfxbackend Choose the renderer. OpenGL is safest; Vulkan can offer better performance on some GPUs. => OpenGL opengl, Vulkan vulkan.
AUDIO LATENCY atari7800.audio_latency Audio buffer length in ms. Raise if you hear crackles or dropouts; lower once audio is stable. => 256 256, 192 192, 128 128, 64 64, 32 32, 16 16, 8 8.
THREADED VIDEO atari7800.video_threaded Offload video work to another thread for better speed on weak CPUs at the expense of latency. => On true, Off false.

libretro: ProSystem

The ProSystem core is a libretro port of the standalone ProSystem emulator. REG-Linux updates it alongside other libretro cores so you can benefit from new fixes and performance tweaks.

Controls

Here is the default Atari 7800 layout mapped to a REG-Linux Retropad:

atari7800

Use RetroArch’s Quick Menu or the ProSystem in-game options if you need alternative mappings.

Troubleshooting

  • Ensure ROMs live in /userdata/roms/atari7800 and use one of the supported extensions. Archives should contain valid .a78 or .bin files.
  • If a title refuses to load or crashes, try another ROM dump or core version—some builds behave differently depending on the specific release.