Reliving the 90s: How AI Built a Virtual Null Modem for Online Quake I

Remember the days when connecting two computers meant fiddling with null modem cables? Neither do most of you—but Pieter Branderhorst does, and he just used AI to bridge a 30-year gap in gaming history.

The Null Modem: A Blast from the Past

For those who missed the era of dial-up modems and serial cables, a null modem was essentially a direct wire between two computers. If you wanted to play multiplayer games but couldn't afford a network card, you'd connect your PC to your buddy's PC via this special cable and enjoy head-to-head frag sessions. It was the original local network gaming—minus the LAN party snacks.

The Problem: Quake I Multiplayer in DOS Wasn't Built for the Internet

Quake I, the legendary 1996 shooter from id Software, was ahead of its time in many ways. But its multiplayer architecture? Designed for direct connections. Getting it to work over the modern internet requires some creative engineering—something that had stumped developers for years.

Until this week, apparently.

Enter AI-Assisted Development

Branderhorst had been trying to get Quake I DOS multiplayer working for two years. Traditional approaches meant diving deep into low-level COM port handling, DOSBox internals, and WebSocket communication—a skillset that takes serious time to develop.

This week, with AI assistance, it took about an hour.

The solution? A web-based virtual null modem that intercepts COM1 communications from Quake I running in DOSBox, forwards that data through WebSockets to another browser instance, and reconstructs the connection on the other end. Suddenly, two players on opposite sides of the planet can connect their DOS-era machines through the magic of modern web technology.

Why This Matters for Developers

This isn't just about nostalgia gaming (though that's pretty cool). This project demonstrates something profound about AI-assisted development:

AI can compress months of learning into hours of implementation.

Understanding how null modems work, how DOSBox handles serial ports, and how to bridge that gap with WebSockets—Branderhorst estimates this would have taken months of research. Instead, AI helped him connect the dots in record time.

For developers and startups, this is the real takeaway. The question isn't whether AI can help you build things faster—it's whether you're leveraging these tools to tackle problems that previously seemed insurmountable.

The Technical Recipe

So what does this stack look like? Based on the available information:

• DOSBox for running Quake I in its native DOS environment
• JavaScript COM port interception to capture serial communications
• WebSockets for real-time bidirectional data transfer
• A simple HTML interface to connect two browser instances

It's elegant in its simplicity. No complex backend, no cloud infrastructure to manage—just pure creative problem-solving augmented by AI assistance.

What This Means for "Vibe Coding"

At NameOcean, we've been talking about vibe coding—the emerging paradigm where AI helps developers express their intent directly, handling the implementation details that traditionally required years of experience to master.

This Quake I project is vibe coding in action. The developer had a vision (playing multiplayer Quake I online), understood the problem space (null modems and serial communication), and used AI to bridge the gap between concept and implementation.

The result? A working prototype in an hour that would have otherwise remained on the "someday" pile indefinitely.

Getting Started

Want to try it yourself? Here's how:

1. Exit to DOS (ALT-F4 or FN-Option-F4 on Mac)
2. Navigate to your Quake directory
3. Launch Quake and press ESC
4. Select Multiplayer → Direct Connect
5. Keep settings matching between players

The virtual null modem handles the rest, creating a bridge across the internet that makes your two DOS machines think they're connected by a physical cable.

The Bigger Picture

Projects like this remind us why we love this industry. The web platform continues to evolve in unexpected ways, and AI is dramatically lowering the barrier to creative experimentation.

Whether you're building nostalgic gaming experiences, modern web applications, or anything in between, the tools available today make it easier than ever to turn ideas into working prototypes. The only real constraint is imagination.

What old technology will you bridge to the modern web?

Have you built something creative with AI assistance? Share your experiences—we'd love to hear how developers are using these new tools to bring their ideas to life.