A keyboard-driven game & software launcher that boots in place of the Finder and turns a vintage Mac into an appliance. Power on, land in a clean library of classic Mac games and apps, pick one with the arrow keys, hit Return, play, quit — and you're right back in the menu. The model is the AmigaVision boot shell: a fast, legible, controller-friendly front end that hides the file system behind a curated, categorized library.
It targets real 68k hardware and MiSTer FPGA cores (Mac Plus, Mac LC, Mac II) alike, so it has to feel good with a gamepad → key mapping, not just a mouse. One 68k binary spans System 6.0.8 through 7.5.5 and black-and-white through 24-bit colour, detecting the machine at boot and coming up at the deepest screen depth the display card supports.
On first run MacAtrium asks how you'd like to browse; the View menu switches at any time. All three share the same paged catalog, deferred cover art, and controls.
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| Carousel — a 5-up cover flow with a large detail pane. Best for a keyboard or controller. (dark theme shown.) | Icon Grid — a Finder-style grid of covers with a live detail panel. Best with a mouse. |
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| List Browser — a categories pane plus a sortable list with a screenshot strip. Best for big libraries. | MacAtrium Status — the memory & art capability set the launcher computed at boot. |
MacAtrium sizes itself to whatever it wakes up on. Crucially, screen depth and art depth are separate axes:
- Screen comes up at the deepest depth the display card can show — 24-bit "Millions" on an 8•24 card, 256 colours on an 8-bit card, 1-bit on a compact.
- Art is baked at 1-, 8-, and 24-bit, and the launcher loads the deepest variant the memory partition can hold, checking each cover's size up front and degrading a tier (24 → 8 → 1) instead of running out of memory. A deep screen on a small partition keeps the deep screen and simply shows shallower art.
- MacAtrium Status (in the menu) reports the partition it was granted, the art budget, and which tiers this machine can both display and hold.
A single disk can carry several System Folders — for example 6.0.8, 7.1 and 7.5.5 — with MacAtrium installed into every one (a Startup Item under 7.x, the Finder itself on 6.0.x). The built-in System Folder Chooser blesses a different System and asks you to shut down cleanly — the 68k cores can't reboot in place — so the next power-on lands in the OS you chose, still inside MacAtrium.
Everything is driven by a tiny key set so a MiSTer joystick → key mapping covers it. The mouse works but is never required.
| Key | Action |
|---|---|
← → |
Move between titles |
↑ ↓ |
Change category |
Return |
Launch the selected title |
I |
More info (year, developer, genre, description) |
P |
Box art, full-screen |
Esc |
Menu — Settings, MacAtrium Status, System Folder Chooser, return to Finder, Shut Down |
The detail pane shows a screenshot as the primary cover; box art is one P
keypress away. Settings cover the browse view, colour depth, artwork preference,
theme, text size, sound, and a "safe mode" that disables launching for browsing.
- Boots as the Finder. On System 6 the launcher replaces the Finder file; on 7.x it installs as a Startup Item under MultiFinder. The user never has to see the desktop.
- Paged, curated catalog. The library is a generated catalog, not the file system. Titles are grouped into categories (Recommended is the default landing view); each category is paged and loaded on demand, so a library of well over a thousand titles stays within a compact Mac's memory.
- Adaptive display & art. The launcher detects the card's depths at boot, comes up at the deepest, and picks the art tier the partition can hold — never OOMing on a cover it can't fit.
- One 68k binary spans System 6.0.8 through 7.5.5 and B&W through 24-bit colour.
One launcher binary; ready-to-run disk images tuned to the machine. Each carries the full installable library (apps are ~95% of every disk); they differ only in art depth and the launcher's memory partition. A single multi-system disk can also carry several of these System Folders at once (see above).
| Edition | Machine / OS | Art | Verified on |
|---|---|---|---|
| B&W | Mac Plus/SE/Classic · System 6.0.8 | 1-bit | Snow (Mac II) |
| Colour | Mac LC/II · System 7.1 | 1-bit + 8-bit (256) | Snow + MDC |
| Quadra / full | Quadra 800 (68040) · System 7.5.5 | 1-bit + 8-bit + 24-bit "Millions" | QEMU Quadra 800 |
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| Launch & return — hit Return to run the app; quit and you're back at the exact spot you left. | B&W edition — the same single 68k binary, adapted to 1-bit on a System 6.0.8 compact Mac. |
Disk images are assembled by the atrium tool (Rust, in tools/atrium-tool/)
on top of rusty-backup's rb-cli
for HFS volume I/O. The 68k launcher itself is built with
Retro68.
# 1. Build the 68k launcher with Retro68 -> build/MacAtrium.bin.
# (Build/install the Retro68 toolchain first, then point CMake at its toolchain.)
export RETRO68=/path/to/Retro68-build
cmake -S . -B build \
-DCMAKE_TOOLCHAIN_FILE=$RETRO68/toolchain/m68k-apple-macos/cmake/retro68.toolchain.cmake
cmake --build build
# 2. Build the atrium image tool (reads the launcher from build/MacAtrium.bin).
cargo build --release --manifest-path tools/atrium-tool/Cargo.toml
# 3. Assemble a disk image from a build config. Start from builds/example.json;
# rb-cli (from rusty-backup) must be on your PATH.
./tools/atrium-tool/target/release/atrium image --config builds/example.jsonA build harvests apps from donor disks, enriches metadata + art from the
Macintosh Garden archive, bakes the catalog, and injects everything into a
bootable HFS image. atrium install-all-systems adds the launcher to every System
Folder of an existing multi-system disk. See docs/ for the full architecture and
design notes.
Beta. The editions build clean, the Quadra edition is emulator-verified end-to-end, and the memory/art adaptation is validated across partition sizes in Snow. The front end is functional and under active polish. Curation of the Recommended list draws on community favourites from the vintage-Mac forums.
Recommendations are curated at build time — contributions to the library and the recommendations list are welcome.
- rusty-backup —
rb-cli, the HFS/disk-image engine. - Retro68 — the 68k Mac cross-compiler.
- Snow and QEMU — headless emulation for verification.
- The Macintosh Garden — artwork and metadata for the library.
MacAtrium's source code is MIT-licensed — see LICENSE. The bundled library data derives from the Macintosh Garden and is included for preservation; see NOTICE.md. MacAtrium ships no Apple ROMs, system software, or game binaries — you supply those yourself.
Contributions to the code, the library, and the Recommended list are welcome — see CONTRIBUTING.md.