The Walter multi-radio modem gives the Commodore 64 something it never had in its heyday: multi-network connectivity. Built around the QuickSpot Walter module, this clever add-on links to the user port via UART, unlocking communication over Wi-Fi, BLE, LTE Cat-M1, LTE Cat-NB1/2, and GNSS. In short, it lets the C64 chat with modern networks that didn’t exist when floppy disks ruled.
Hardware That Bridges Two Eras
At the heart of this project sits QuickSpot’s Walter module, a compact powerhouse that combines multiple radio technologies on one board. The Commodore 64 connects to it through the user port, powered by a USB-C connector that also doubles as the programming interface.
Because the C64’s UART operates at 5V TTL and the Walter module runs at 3.3V logic, two bi-directional MOSFET level shifters handle signal conversion. This small but important detail keeps both systems speaking the same electrical language—vintage compatibility meets modern engineering.
Software and Functionality
The Walter multi-radio modem uses a passthrough setup based on the Sequans GM02SP’s AT command interface. Through this, the C64 can directly issue modem commands, treating Walter as a smart, external link to today’s networked world. It’s a surprisingly smooth bridge between 1980s computing and 2020s IoT capability.
Why It Matters
Retro enthusiasts love breathing new life into classic machines, and the Walter expansion is a perfect example. It transforms the Commodore 64 into a network-aware device while preserving the machine’s old-school charm. For hobbyists, tinkerers, and collectors, it’s proof that the C64 can still surprise—this time, by going online in style.
To see how it all comes together, the accompanying video walks through the design, connections, and software in action.
