At CoCoFEST! 2025, three developers—John Strong, Matt Massie, and John Federico—offered a deep look at the progress of NitrOS-9 on the Foenix F256 line of computers. This wasn’t a surface-level overview—it was a technical walk-through with real demos, practical insights, and hands-on development updates that reflected how far the project has come and where it’s heading.
Why the Foenix F256 Matters for NitrOS-9
John Federico opened with an overview of the hardware. The Foenix line, developed by Stephanie Allaire, includes multiple CPU variants—6502, 65816, and 6309—with support for a possible 68000 core in the future. Of particular focus was the F256K and its successors: the K2 and the compact “Junior Junior.” These models offer improved usability, onboard RAM upgrades, and easier FPGA updating via USB—leaps ahead of the original designs that required Quartus and external USB blasters.
Federico likened the machine to “a Commodore 64 on steroids,” but with a 6 MHz 6309 CPU, 512K of RAM (expandable), and a feature set that lets it run unmodified CoCo 3 console apps via NitrOS-9. That binary compatibility between CoCo 3 and the Foenix machines is no small bonus—programs built in Semok or transferred from the CoCo 3 work directly.
OS9 on Foenix: A Familiar Yet Expanded Toolkit
Most development uses existing CoCo tools—LWTools, ToolShed, and now the Fenix Manager, a utility for handling the onboard flash memory. All tools are available through Henry Strickland’s “Coco Shelf” GitHub repo.
There’s even a meme-based IDE in the works. But the real draw? Running NitrOS-9 directly from flash at boot. Level One boots instantly and acts as a gateway to load the full OS via SD card, cartridge, or DriveWire.
Graphics, Sound, and Hardware Layers
Federico walked through the F256’s layered graphics system, which supports three bitmap or tilemap layers plus four sprite layers. Resolution hits 320×240 at 60Hz, with options for 70Hz at slightly reduced resolution. He demonstrated live bitmap rendering with individual color lookup tables per layer—something previously unseen in this segment of retro computing.
The machine also features PS/2 input, DVI video out via HDMI ports, a real-time clock, and a built-in MIDI chip (Dream SAM 2695) in newer models. Audio gets serious attention too: dual SID chips (soft or real), OPL3, and PSG.
Networking is handled through the Whisfy360 chip, behaving like a Hayes modem. The K2 even adds wired Ethernet support and an on-board RP2040 microcontroller that loads FPGA cores—no PC required.
Keyboard, Mouse, Fonts, and Terminal Tricks
The team implemented a PS/2 mouse driver with auto-hide and interrupt detection. For text rendering, a font management system allows users to switch fonts mid-screen using raster interrupts, and the font system supports extended characters 0–31 via a new escape sequence.
A font preview tool shows how fonts appear in various resolutions and colors, allowing on-the-fly customization. They’ve grouped all fonts into a new “CIS Fonts” directory and developed a loader to dynamically change styles, giving text-based apps a visual boost.
What Still Needs Work
While NitrOS-9 runs well, there are still gaps. Multi-terminal support isn’t ready yet due to memory limitations and pending DMA updates in the FPGA core. Graphics memory must still sit inside the first 512K, and while flags exist to handle this, more drivers and tooling are needed.
More development tools on the actual Foenix system—like a native assembler or C compiler—are high on the wishlist. Documentation and updated GitHub repositories were acknowledged as works in progress.
Extending BASIC09 for Everyone
Matt Massie demonstrated his extensive work on BASIC09, expanding it for modern hardware and graphical output. He’s added over 50 new commands, enabling bitmap drawing, font loading, and mouse input—all directly from BASIC.
Massie also built a file browser in BASIC09 featuring a live preview for fonts and backgrounds. Backgrounds load via themes, which can be selected at startup for a more visually customized OS9 shell experience.
He even implemented sprite previewing, bitmap painting tools, and a graphical Mandelbrot renderer—all from BASIC. His work provides an approachable route for users who aren’t fluent in assembly, broadening access to development on the platform.
A Community Effort
Throughout the session, all three developers emphasized collaboration and building on each other’s contributions. Strong plans to further refine the font rendering and sprite handling, and Federico’s utilities have already been adopted into the project’s toolkit. The team hopes to make it easier for users to develop directly on the hardware, without relying on a Linux or Windows PC.
For anyone interested in retro-inspired hardware with serious horsepower and a modern OS to match, the Foenix F256 and NitrOS-9 pairing is becoming hard to ignore.
