C64U Slim-Viewer

A lightweight, high-performance video viewer for the Ultimate 64 (U64) and C64 Ultimate. This tool utilizes the hardware's built-in VIC-stream to display your C64 screen directly on your PC with minimal latency—no capture card required. Built with .NET 8 and Avalonia UI.

📺 Overview

The C64U Slim-Viewer allows you to stream the VIC-II video output of your Ultimate 64 directly to your modern linux or windows desktop via your local network.

Key Features

🚀 Low Latency: The tool operates as a passive UDP listener. It no longer sends active control commands to the hardware, minimizing network overhead and avoiding conflicts with other tools. You control the stream directly from your C64. As soon as the hardware starts sending data, the viewer displays the frame.
🪶 Minimalist Design: A distraction-free window perfect for coding or gaming.
🔄 Auto-Update Check: In-app notifications for new GitHub releases.
🐧 Cross-Platform: Native support for Linux (.deb) and Windows.

🕹️ Supported Hardware

Ultimate 64 / Ultimate 64 Elite (Full support)
Ultimate-II+ (Standard version with Ethernet)
⚠️ Note: The Ultimate-II+L (L-version) is NOT supported, as it lacks the video streaming capabilities in its hardware/firmware.

☕ Support

This software is a passion project by a private developer. If you find it useful, your support is greatly appreciated!

➡️ Buy me a coffee on Ko-fi

🔌 Setup Instructions

Follow these steps to establish a connection between your C64U and this viewer.

1. Network Requirements

Ensure your Commodore 64 Ultimate (C64U) is on the same local network as this PC.
Important: Your C64U must be connected via LAN. Disable WLAN on the C64U to ensure a stable stream.

2. Firewall Settings

Ensure that Port 11000 for UDP is open in your PC's firewall. This port is required to receive the incoming data stream.
Windows: You usually don't need to do anything. Windows Firewall will automatically ask for permission on the first startup. Ensure you allow access.
Linux: Most distributions (like Ubuntu, Mint, Debian) don't block this by default. However, if you have a strict firewall enabled (like ufw), you must manually allow UDP traffic:
```
sudo ufw allow 11000/udp
```

3. Configure the C64U Hardware

Now, you need to tell your Ultimate 64 where to send the video data:

Step A: Configure Data Streams

In the C64U main menu, press F2 (SHIFT+F1).
Navigate to Data Streams -> Stream VIC to:.
Replace the existing IP address with your Client-IP (your PC's IP) and port 11000.

Step B: Start the Stream

In the C64U main menu, press F1.
Navigate to Streams -> VIC Streams -> Send to [Client-IP]:11000.
Press Enter.

📦 Installation

Linux (Debian/Ubuntu/Mint)

Download the latest .deb package from the Releases page.
Install via double click or terminal: sudo dpkg -i c64uviewer_*.deb

Windows

Download the C64UViewer_Windows.zip from Releases.
Extract and run C64UViewer.exe.

🛠️ Build from Source

Install .NET 8 SDK.
Clone: git clone https://github.com/gruetze-software/C64UViewer.git
Build: dotnet build -c Release

📄 License

This project is licensed under the MIT License.

❤️ Credits

Developed by Grütze-Software.
Special Thanks to Perifractic (Retro Recipes): For his incredible passion, for bringing the C64 into the modern era, and for inspiring projects that bridge the gap between retro and contemporary computing.
Gideon's Logic: For creating the amazing Ultimate 64 hardware.

📜 Disclaimer

C64U Slim-Viewer is provided "as is," without warranty of any kind, express or implied. The author is not liable for any damages or losses arising from the use or inability to use the software.
This software is a hobby project developed in the author's spare time.
It is not a commercial product and comes with no official support.
Use it at your own risk.

gruetze-software/C64UViewer