¶ Technical data
- Manufacturer: Atari
- Year of release: 1986
- CPU: Atari SALLY 6502C @ 1.79 MHz
- RAM: 4 KB
- Video: MARIA
- Resolution: up to 320x240, 256-color palette
- Sound: TIA, 2 channels (some cartridges carry an extra POKEY chip)
- Media: cartridge
¶ Presentation
The Atari 7800 ProSystem was designed as early as 1984 by General Computer Corporation to take the market back from the ColecoVision. Its novelty is the MARIA graphics chip, able to display a very large number of moving objects at once — far more than the 2600 or the 5200 — at the cost of a sound chip left unchanged from the 2600, the ageing TIA. Some publishers worked around that limit by soldering a POKEY chip straight into the cartridge, which yields noticeably better-sounding games.
The console also fixes the 5200's two biggest flaws: it is compatible with nearly every Atari 2600 cartridge, with no adapter, and it returns to a classic digital joystick with two buttons. Its release was nonetheless delayed by two years: Atari was sold to Jack Tramiel in 1984 and the project stayed on the shelf until 1986.
By the time the 7800 finally reached the shops, the Nintendo Entertainment System had already taken over the North American market. Despite good arcade conversions — Ms. Pac-Man, Joust, Robotron: 2084, Xevious, Food Fight — the library stayed short and many titles were re-skinned 2600 games. Atari kept it in the catalogue until 1992; it is being rediscovered today thanks to a homebrew scene that still produces new games.
¶ Emulators
Emulator availability per board:
| Emulator | RPI3/RPI02W | RPI4/400 | RPI5/500 | OGA/OGS/RG351 | PC | RG353 |
|---|---|---|---|---|---|---|
| Libretro ProSystem | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
ProSystem is Recalbox's only Atari 7800 emulator, and it is available on every board: high compatibility and high speed, including on RPi3 and RPi Zero 2. It is flagged as compatible with CRT output. Netplay and softpatching are not available on this system. RetroAchievements are supported.
¶ BIOS
The Atari 7800 BIOS files are optional: ProSystem starts games without them. Their only role is to show the official Atari boot screen, and they lock the console to their region — the US BIOS only runs US games, the European BIOS only runs European games. If your collection is mixed, the simplest choice is to install neither.
| File name | Description | MD5 | Emulators |
|---|---|---|---|
7800 BIOS (U).rom |
US BIOS (optional) — runs US games ONLY, displays the official Atari logo | 0763f1ffb006ddbe32e52d497ee848ae | ProSystem |
7800 BIOS (E).rom |
European BIOS (optional) — runs European games ONLY, displays the official Atari logo | 397bb566584be7b9764e7a68974c4263 | ProSystem |
If you do choose to install them, place them like this:
/recalbox/share/bios/atari7800/
├── 7800 BIOS (U).rom
└── 7800 BIOS (E).rom
The file name must be reproduced exactly, spaces and brackets included.
¶ Roms
Put your games in:
/recalbox/share/roms/atari7800/
Supported extensions: .a78 .bin .cdf .zip .7z
Prefer the
.a78format, which carries a header describing the cartridge type (mapper, presence of a POKEY chip, region). A plain headerless.binmay be misdetected and end up silent or refuse to start.