Running Contiki-NG On C64 With Networking

Jan 17, 2026 by Editorial Team 42 views

Hey guys, this is a cool project to get Contiki-NG running on the Commodore 64! Let's dive into how to get Contiki-NG working on a C64, especially when you're trying to get networking going. You're already running the C64 version, which is fantastic! The main hurdle seems to be getting the network interfaces of your C64Ultimate board to play nice with Contiki-NG, instead of just emulating a modem. We'll explore how to configure Contiki-NG to use a SwiftLink compatible modem and dial up some PPP. The default configuration of your C64Ultimate board is set up for modem emulation via ACIA/SwiftLink. We'll need to figure out how to bridge this to a network connection.

Setting Up Networking with Contiki-NG on C64

Okay, so the setup uses the C64Ultimate board (V1.47). The board's modem interface, using ACIA/SwiftLink, is emulating a modem, which isn't ideal for direct networking. The board's setup shows the modem interface, ACIA (6551) mapping, hardware mode, SwiftLink, and listening port (3000) are all ready. To use this with Contiki-NG, we need to bypass this and connect directly to the network. You could set up a PPP server on your Raspberry Pi to handle the dial-up connection. You'd configure Contiki-NG on the C64 to connect to the SwiftLink, which in turn connects to your Raspberry Pi via a serial connection. Your Raspberry Pi will then handle the PPP connection to get you on the network. But there's a few steps we have to go through to make sure everything lines up and works well. The configuration shows the board handles ring sequences, drop connections, and RTS/CTS handshaking. These modem settings should be tweaked to ensure they correctly interface with your setup. The board also uses text files for welcome messages and busy indications.

Required Components and Configuration

To make this work, here's what you'll typically need:

C64 with C64Ultimate Board: This is your hardware platform. Make sure the board is properly configured for SwiftLink or ACIA operation.
SwiftLink Modem: Or any other compatible modem or modem emulation setup through the C64Ultimate board. This will serve as the interface between your C64 and the external network.
Raspberry Pi (or similar): This will act as your PPP server. It will handle the network connection and provide a gateway for your C64.
Contiki-NG Image: You'll need a properly built .d64 disk image with Contiki-NG configured for networking and SwiftLink/ACIA.
Serial Cable: For the connection between your C64Ultimate board and your Raspberry Pi (or whatever device you're using for PPP).

Step-by-Step Configuration Guide

Raspberry Pi Setup: On your Raspberry Pi, install and configure a PPP server (like pppd). Set it up to listen for connections from the C64 and handle the dial-up process. Ensure that the serial port on the Pi is correctly configured to communicate with the C64Ultimate board.
C64Ultimate Board Configuration: Configure the C64Ultimate board to use the SwiftLink/ACIA in the correct mode. Set up the serial port settings (baud rate, etc.) to match the Raspberry Pi's configuration.
Contiki-NG Configuration: Within Contiki-NG on the C64, configure the network interface to use the serial port connected to the SwiftLink/ACIA. You'll need to write a specific Contiki-NG configuration to use the serial connection. You might need to change the network configuration settings to match your Raspberry Pi PPP server.
D64 Image: Load your configured Contiki-NG image onto the C64. Make sure that the image contains the necessary network drivers and configurations. The core of your Contiki-NG configuration will be its network settings, which must match the setup of your Raspberry Pi's PPP server and your C64Ultimate board's serial settings.
Testing and Troubleshooting: After these steps, try to connect from the C64. Use the Contiki-NG applications to test the network connection. Check the serial connection and PPP configuration on your Raspberry Pi. If things aren't working, check the serial connections and the PPP logs on your Raspberry Pi for errors.

Deep Dive into Contiki-NG and C64 Integration

Now, let's get into the nitty-gritty of getting Contiki-NG to sing on the C64. Contiki-NG is a lightweight operating system designed for networked, memory-constrained systems. It's perfect for something like a C64. The whole idea is to get the C64 to talk to the network like it's supposed to, not just pretend to be a dial-up modem. Because of the limited resources, Contiki-NG uses a very small footprint which means it's possible to run on the C64. You'll need to delve into the source code and modify it to work specifically with the C64. This means adjusting things like the network drivers and the serial port settings, because you're working with very specific hardware. The serial communication setup is important, as Contiki-NG needs to know how to talk to your SwiftLink, which then talks to your Raspberry Pi via a serial connection. This is where you configure the serial port for your setup. The baud rate, data bits, parity, and stop bits must match on both the C64 and Raspberry Pi to ensure the communication flows well.

Contiki-NG Configuration for Serial Communication

In Contiki-NG's source code, you'll probably need to modify the network drivers to use a serial interface. Specifically, you'll need to:

Locate the Serial Driver: Find the part of the Contiki-NG source code that handles serial communication. This will vary depending on your setup.
Modify the Driver: Adapt this driver to work with your SwiftLink/ACIA setup. This could involve configuring the serial port settings (baud rate, etc.) and handling the AT commands if necessary.
Network Interface Configuration: Define a network interface that uses the serial port. This will tell Contiki-NG how to send and receive network data.

Building the D64 Image

Once you have your Contiki-NG code ready, you'll need to create a .d64 disk image. This image will contain the Contiki-NG operating system and your custom network configurations. Building a .d64 image involves the following steps:

Compile Contiki-NG: Compile your modified Contiki-NG source code for the C64.
Create the Disk Image: Use a tool to create a .d64 image. This image will contain the Contiki-NG kernel, applications, and any necessary configuration files.
Load the Image: Load the .d64 image onto your C64 using an emulator or a hardware device that can load disk images.

Troubleshooting Networking Issues

Okay, so you've set everything up, but your C64 isn't connecting to the internet. Don't worry, it's pretty normal to run into issues! Let's troubleshoot.

Serial Communication: The most common issue is problems with the serial connection between the C64Ultimate and your Raspberry Pi. Check the baud rate settings, data bits, parity, and stop bits on both ends. Make sure the serial cable is properly connected.
PPP Configuration: On the Raspberry Pi, double-check your PPP configuration. Make sure it's set up to listen for connections from the C64, and that the username and password (if applicable) are correct.
Contiki-NG Configuration: Verify the network settings in Contiki-NG. The IP address, subnet mask, and gateway settings must be correct for your network. Check the network interface settings to make sure they are correct and point to the serial port.
Firewall: Make sure your Raspberry Pi's firewall isn't blocking the connection. You might need to open specific ports to allow the C64 to communicate.
Logging: Use logging to troubleshoot. Enable logging on the Raspberry Pi and within Contiki-NG to see what's happening. This will help you identify any errors or problems.
Modem Commands: Review the modem settings and handshaking to make sure the C64Ultimate is correctly passing information between the C64 and the serial port.

Contiki-NG's Role and Potential Applications

Contiki-NG isn't just a basic OS; it's designed with the Internet of Things (IoT) in mind. It's incredibly well-suited for devices with very limited resources like the C64. This makes it a perfect fit for experimental projects and bringing the old tech into the modern world. With Contiki-NG, you could potentially do some pretty cool stuff:

Home Automation: Control lights, sensors, and other devices from your C64.
Data Logging: Collect and store data from sensors connected to the C64.
Retro IoT Projects: Build vintage-style IoT devices that connect to the internet using the C64.

By getting the C64 and Contiki-NG working, you're not just playing with an old computer. You're experimenting with embedded systems, networking, and the way devices communicate, which is a great learning experience. It combines old and new tech and opens up some really cool possibilities!

Key Considerations and Potential Improvements

Here are some final points to consider when setting up Contiki-NG on your C64:

Disk Image: Finding a recently built .d64 image with Contiki-NG could make a huge difference in getting started. Check the release sections on GitHub and forums for pre-built images, or ask around. If you find one, it'll save you a ton of time on the initial setup and configuration.
Documentation: There's a lot of information on the web about Contiki-NG. Use it! Check the official documentation for Contiki-NG and the C64 resources. There are also many forums and online communities dedicated to retro computing. These groups can be invaluable, so look for forums and websites dedicated to the C64 and Contiki-NG.
Adaptation: The C64 version of Contiki-NG is not actively maintained, so you might need to adapt it. If you're comfortable with coding, you may need to tweak the code. Make sure to document your changes so that others can easily follow in your footsteps.
Performance Optimization: Contiki-NG is designed to be lightweight, but performance can be a concern on the C64. Try to keep the applications and drivers as streamlined as possible. Less is more when it comes to the memory-constrained environment of the C64.

Hopefully, this gives you a good start to getting Contiki-NG and networking running on your C64. Good luck and have fun!