Modern software for the TRS-80 Color Computer 3
New programs, written today, for a machine from 1986 — a graphical desktop, utilities and games for the TRS-80 Color Computer 3, by Keith Clark of Rodney, Ontario.
The Color Computer 3 was never held back by its hardware. Its GIME graphics chip, the HD6309 processor and a real multitasking operating system in NitrOS-9 were ahead of what most home computers of its day were doing — what it never got was software written to that standard. That is the gap this project exists to close.
“My overall project here is to bring the true power of the CoCo 3 out to the community and the software where it should have been back in its heyday. It would have taken over Commodore and Atari computers I think. Or at least I'm going to try to do it that way.”— Keith Clark, on the project
Everything here is written from scratch, today, with modern tools — and built for the machine at its best: the full 2 MB of RAM, the HD6309, a Multi-Pak Interface and Orch-90 sound. In 1987 that stack cost a fortune and most owners never touched it; today an emulator hands it to everyone for free, so these programs build for the CoCo 3 at its maximum, no apologies.
And it is built the way community software should be: in the open, with original code, honest screenshots and honest status labels — what is released is released, what is still on the bench says so. When a program is ready, it will simply be given away to the community that has kept this machine alive for forty years.
“We're going to use every capability of this little baby.”— Keith, setting the design rule for everything built here
The projects below are not a scattered hobby list — they are one build, with one destination: a complete CoCo 3 with all available software and our own programs. One machine, assembled in the open: the whole preserved library of CoCo software, and a new suite of programs written for it today, living together behind one desktop.
“A complete CoCo 3 with all available software and our own programs.”— Keith Clark, naming the project's goal, 4 November 2026
The foundation is NitrOS-9 EOU, the community's modern OS-9 distribution. On it sits Prism, the graphical desktop — the machine's face. Around Prism grows a suite of home-grown programs, all written here: the System Monitor, an Orchestra-90 music player (built, and on the test bench — its playback is being perfected) and PSG sound work through the Multi-Pak, played and verified by ear — one family of software, built as one machine's own.
The library is the Color Computer Archive's — four decades of CoCo software, preserved by the community. Their work, not ours, and credited as such. A local copy of their SDC card image is now in hand and verified (4 November 2026: 5,367 files, 5,282 disk images). The next major piece, the Librarian, will index that library so the whole collection can be browsed, searched and launched from inside Prism — a few keystrokes away, inside the machine.
Librarian · In design — library in hand, index next
First — in development
Prism, completed
The shell's menu and directory work finished — Prism as the machine's face, made whole.
Next — in design
The Librarian
Browse, search and launch the entire Archive library from inside Prism.
Then — in design
Full RAM
Prism rebuilt around the whole 2 MB, page-swapped — the full-RAM build.
Then — on the roadmap
A window manager
Overlapping, resizable windows — Prism's own windows, stacked and sized at will.
The crown — in design
The strategy game
A real-time strategy game in the Age of Empires mould, built on everything that comes before it.
One flagship, out the door — and the bench behind it. Each project gets its own page as it matures; statuses are kept honest.
A Finder-style graphical shell for the CoCo 3 under NitrOS-9 EOU: a menu bar, badge-style drive tiles, draggable windows and double-click program launching — the desktop the machine always deserved. Written from scratch in C, and free and open source (MIT). Version 0.2.1 is public now; the exhibit at home already runs v0.2.7 (v0.2.6 pictured here).
A utility in the Prism ecosystem that shows what the machine is doing: processes, memory — with the map of the GIME's 8K blocks — CPU load, drive space and uptime.
A music demo for the Orchestra-90 cartridge, run through the Multi-Pak Interface: four synthesized voices in stereo, played by the CoCo 3 itself — a showcase for the sound hardware most owners never heard used properly. Honest status: built and installed in the exhibit, but its playback failed live testing — wrong speed, unanswered keys — so it is on the bench being rebuilt, not yet singing.
No page yet — it gets one when it sings
The index to the whole library: a Prism program to browse, search and launch the entire Color Computer Archive collection from inside the machine. The library is the Archive's — preserved by the community; a local copy of their SDC card image (5,367 files · 5,282 disk images, verified 4 November 2026) is in hand. What is ours is the index. Status: in design — library in hand, index next.
A real-time strategy game in the Age of Empires mould — villagers, resources, armies, built for the CoCo 3: a genre the machine never had. Currently on the drawing board, designed from the start against the full 2 MB machine.
No page yet — still on the drawing board
6 November 2026 — Curtis Boyle, who maintains EOU, has granted permission to bundle EOU with the portable Prism package and blessed its submission to the Color Computer Archive — and will present these pages as a preview on tomorrow's CoCo show (Saturday, 7 November), inviting viewers to help test Prism.
5 November 2026 — Prism v0.2.1 and its boot package were published on GitHub — the first public release.
Every build is written up as it happens: dated bulletins for the announcements, and a complete changes log — version by version, detail by detail — for anyone who wants the whole story.
The archive
The community's library of CoCo software, documentation and history — where finished projects here will also be shared. A local copy of their SDC card image now sits at the heart of the Complete CoCo 3 — see the vision.
The source
All of the code, in the open — repositories, releases and the project pages, as each program matures.
Say hello
Questions, suggestions, a change you'd like to see — or criticism, which is just as welcome. Testers are especially welcome — write and say you'd like to try Prism.