Get Vintage PCs Back Online With a DIY Dial-Up ISP

Getting a vintage computer on the internet can be a challenge these days. Even computers from the late-1990s — back when the phrase “information superhighway” was on everyone’s tongue and the name of every new device started with a lowercase “I” — are tough to get online. If you happen to have a vintage Ethernet card, it makes things pretty simple, but that was a luxury for a personal computer of the era. Far more common were dial-up modems.

Even if you are one of the few people with an active telephone line in your home, finding a local dial-up ISP is impossible in most areas. Fortunately, as Jeff Geerling recently proved, you don’t need to sign up for a dial-up service to get aging machines online. You can build your own dial-up ISP instead. Don’t worry, this isn’t some elaborate setup with multiple lines and a PBX — it’s just enough to get one classic computer on the internet, and it costs about $200 if you buy everything new.

The project is built around a Raspberry Pi — any modern model from the Pi 3 onward will do. This tiny computer acts as the ISP, answering incoming calls from a vintage machine’s modem and routing its traffic to the modern internet. To bridge the gap between decades-old hardware and today’s networks, the setup also uses a USB dial-up modem and a line simulator, which effectively replaces the need for a real telephone network.

The USB modem plugs directly into the Raspberry Pi, while a line simulator connects the Pi’s modem to the retro computer’s modem using standard telephone cables. The simulator mimics the electrical characteristics of a real phone line, allowing the two devices to “dial” and perform the familiar handshake sequence. With a small tweak to the simulator’s settings, stable connections of up to 28.8 kbps are achievable.

On the software side, the system is automated using Ansible, making deployment relatively painless. Once configured, the Pi listens for incoming calls and authenticates connections using default credentials. From the perspective of the vintage machine, the experience is almost indistinguishable from dialing into a real ISP in the 1990s, complete with the iconic chirps and screeches of modem negotiation.

Once online, the first thing you’ll notice is that you can access almost no websites with an ancient browser. To make the modern web more accessible, the setup can also run a lightweight proxy that strips down websites into something older browsers can handle. This allows machines running operating systems like classic Mac OS or Windows 95 to load pages that would otherwise be unusable. There’s even an option to browse the web through archived snapshots, effectively letting users explore the internet as it existed decades ago.

If you’d like to try this project out for yourself, head on over to GitHub for all the details you need.