At Pacific Commodore Expo NW 2025, Stephen Jones shares a practical walkthrough of C64 OS with TeensyROM, a combo that brings new utility to the Commodore 64. Filmed by Bernardo at the Old Rainier Brewery in Seattle, this presentation demonstrates real-world use of both C64 OS 1.07 and a beta build of TeensyROM 64/128.
C64 OS with TeensyROM gives the C64 a modern, file-driven GUI that still runs on authentic hardware. Stephen kicks things off with a quick overview of the minimal setup: SD2IEC for storage and JiffyDOS for performance. A simple SID chime later, the C64 loads into C64 OS’s “App Launcher”—a customizable workspace with five switchable desktops.
Navigation is refreshingly responsive. Users can drag icons, open galleries, switch desktops, or launch tools like a built-in Wikipedia reader. The hamburger menu in the corner offers options like returning to BASIC or switching workspaces without the mouse. The whole environment feels like it belongs on something far newer than a 1982 machine.
This is where C64 OS with TeensyROM takes things further. The TeensyROM module, developed by Travis Smith (Sensorium), brings SD card access, a USB interface, and Ethernet support. Stephen’s demo highlights how the latest beta driver enables C64 OS to use the TeensyROM’s Ethernet for live internet applications. One example? A functioning Wikipedia reader that pulls content using Gregory Nacu’s Commodore network service.
Switching into the file manager, Stephen shows how C64 OS remembers recent files and applications. It even supports REU acceleration if present. Then, in a slick moment, he launches the image viewer, pulls up a slideshow of starships, and walks the audience through the layered interface—status bar, shade effects, and image transitions.
The OS uses around 19K of RAM during the demo. Not bad considering it’s running a full GUI with apps, networking, and file operations. While the current TeensyROM beta doesn’t yet expose its USB or SD storage directly through the file manager, Stephen speculates support could arrive in a future firmware update.
Version 1.08 of C64 OS will formally support the beta TeensyROM Ethernet driver. Until then, the demo shows just how capable the current build is. Between the active development by Gregory Nacu and community support from developers like Travis Smith, the future for expanded C64 utility is anything but idle.
