The Commodore 64 has no shortage of flash cartridges, making it easier than ever to load software without the hassle of floppy disks or tape drives. But what if you could take things even further—adding NFC game launching, Internet connectivity, USB storage, and MIDI to your C64? That’s exactly what the TeensyROM brings to the table.
At its core, the TeensyROM is a flash cartridge powered by a Teensy 4.1 microcontroller. This is a very capable MCU, and that’s reflected in the features offered by the TeensyROM. You can load ROMs from a microSD card, USB drive, or even its internal flash storage. But what really sets it apart is its NFC feature. The TeensyROM’s creator, Travis (aka Sensorium), collaborated with NFC launcher pioneer, Wizzo, to bring the NFC launching ecosystem that Wizzo’s been building into the device.
I covered Wizzo’s project, Zaparoo (formerly TapTo) for the MiSTer a while back (video here), and I’ve been a big fan of NFC launchers ever since. They enable you to launch games just by tapping an NFC tag onto a supported USB NFC reader. It brings a physical element back to game selection, solving the all-too-common issue of digital “decision paralysis” when browsing massive game libraries.
These NFC readers aren’t just the boring old, stock USB devices you find attached to a laptop in a doctor’s office. Rather, folks in the community have come up with some beautiful and interesting designs that add a nice aesthetic element to your gaming setup. My favorite, and the one I use in the video, is an NFC reader that resembles a Commodore 1541 disk drive. This model was designed by Ninja3DP, and it looks right at home sitting next to your C64.
While I love the MiSTer and the NFC capability integrated into it, NFC launching actually feels more snappy and natural with the TeensyROM on original Commodore hardware. For my experiments, I used the OneLoad64 collection of C64 games, which are all optimized to load very quickly. In fact, they load so fast, that the games launch while I’m still pushing the NFC card into the reader. It’s an oddly gratifying experience.
Beyond just game loading, the TeensyROM also brings an Internet connection to the C64 through its integrated CCGMS terminal software. Plug in an Ethernet cable, and you can connect to BBSes, browse the web, and even download games directly to the microSD card. Folks in the TeensyROM community have even set up small web servers to serve up files to TeensyROM users over the text-based web browser.
If you’re a musician, you might want to look at the TeensyROM for a different reason – it allows you to connect a USB MIDI keyboard directly to your C64. Using the built-in MIDI2SID software, tickling those ivories will give you the power to masterfully control the SID to produce that sweet track that you can’t seem to shake from your head.
If you’re interested in making your own TeensyROM, my video will take you through the process step-by-step. The TeensyROM GitHub repository has a complete parts list, along with the firmware and other helpful information.
If you don’t want to undergo the task of making one yourself, Travis offers fully assembled TeensyROMs on his Tindie store for a very reasonable price. If you’re able, I encourage you to support Travis by purchasing a TeensyROM directly from him.
The TeensyROM is definitely my new favorite flash cart for the C64. With multiple storage options, network capabilities, MIDI, and NFC support, it pushes the limit of what’s possible to pull off through the C64’s cartridge interface. Want to see it in action? Check out my full video, where I build a TeensyROM, test many of its features, and dive into how it works.