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Atom

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Overview

The Acorn Atom is a compact home computer introduced in 1979 by Acorn Computers. It featured an 8-bit design that bridged the gap between the BBC Micro's predecessors and the later BBC series, and it remains valuable among collectors due to its minimalist keyboard, expandable RAM and strong BASIC support.

In REG-Linux the system uses the atom group so metadata and aesthetics can match the platform’s artwork set.

Technical specifications

  • Manufacturer: Acorn Computers
  • Release year: 1979
  • Hardware type: computer

Supported ROM extensions

wav, tap, csw, uef, mfi, dfi, hfe, mfm, td0, imd, d77, d88, 1dd, cqm, cqi, dsk, 40t, atm, bin, rom, zip, 7z

Quick reference

  • ROM folder: /userdata/roms/atom
  • Accepted formats: .wav, .tap, .csw, .uef, .mfi, .dfi, .hfe, .mfm, .td0, .imd, .d77, .d88, .1dd, .cqm, .cqi, .dsk, .40t, .atm, .bin, .rom, .zip, .7z
  • Emulators: RetroArch (libretro: mess), MAME
  • System group: atom

BIOS

The Acorn Atom relies on the Atom ROM bundle recognized by MAME/libretro: mess. Place the following files into the bios folder with the exact filenames so REG-Linux can detect them:

MD5 checksum Share file path Description
b7b7f8a608339fa39d44a3bcfa2cc3f0 bios/atom.zip Atom ROM image (part 1)
baa26f458acf5745388177ffc7368124 bios/atom.zip Atom ROM image (part 2)
9627dfb5f8302db8dd5702dbf7c09f72 bios/atom.zip Atom ROM image (part 3)

ROMs

Store Atom images in /userdata/roms/atom. Use the appropriate file types listed above, and treat .atm or .bin files the same as raw cartridge dumps. Multi-disk titles should be launched through the emulator’s internal menu (Quickload or disk selection). If a disk doesn’t auto-launch, type the program name followed by the double-quote character (Shift+2) and press Enter.

Emulators

RetroArch (libretro: mess)

RetroArch runs libretro: mess, giving you unified controls, shaders, overlays and hotkeys. Standardized features include atom.videomode, atom.ratio, atom.shaderset, atom.integerscale, atom.bezel, atom.ai_*, atom.runahead and atom.video_threaded.

Key configuration options

ES setting name REG-Linux.conf_key Description => ES option key_value
OVERCLOCK (UNSTABLE) global.mame_cpu_overclock Boost Atom CPU speed (use only if you know the game benefits).
RENDERING RESOLUTION global.mame_altres Increase resolution for crisp rendering.
SOFTWARE LIST atom.softList Tell MESS which media list to use (cassette, disk, ROM).
MEDIA TYPE atom.altromtype Specify whether the file is cassette, disk, value, etc.
CUSTOM GAME CONFIG atom.pergamecfg Enable per-game overrides via the MAME menu.

MAME

MAME also drives Atom emulation directly without RetroArch. Access the in-game menu ([HOTKEY] + south button or Tab) to adjust video, input or audio settings; these options can also be edited via mame.ini. The same option keys (atom.video, atom.bgfxshaders, atom.altdpad, etc.) are exposed to keep the experience consistent.

Controls

Here are the default Atom controls shown on a REG-Linux Retropad:

atom controller overlay

Use RetroArch or MAME’s input configuration if you need alternate layouts for joysticks, paddles or keyboard-driven titles.

Troubleshooting

  • Verify the atom.zip BIOS archive resides in the bios folder and that the MD5s above match.
  • Ensure ROMs use one of the supported extensions and live in /userdata/roms/atom.
  • Some software requires selecting the drive type manually—use the emulator’s internal menu to tell it whether you’re loading a cassette, disk or cartridge image.