HomeTo64: a Home Assistant dashboard for the Commodore 64 Ultimate

The Commodore 64 has been used for almost everything over the past four decades: games, music, programming, education, office work, demos, and plenty of experiments its original designers could never have expected. HomeTo64, a project by GitHub user JKnivesworthy, adds another role to that long list. It lets a Commodore 64 Ultimate display live data from Home Assistant, turning the machine into a working smart home dashboard. The idea is simple enough to understand: Home Assistant already knows the state of your home, from temperature sensors and smart plugs to battery levels, motion sensors, lights, and power readings. HomeTo64 takes selected entities from Home Assistant and sends them to a C64 screen. The result is a page-based dashboard that looks and behaves like a real 8-bit program rather than a retro-themed web page.

How it works

HomeTo64 is installed as a custom Home Assistant integration, either through HACS or by manually copying the integration folder into Home Assistant’s custom_components directory. Once installed, the user configures the IP address of the C64 Ultimate, sets an optional password, chooses how many dashboard pages to use, names those pages, and selects the Home Assistant entities that should appear on each one. The integration supports up to ten pages, with up to ten sensors per page. That is a sensible limit for a 40-column C64 display, where space is valuable and long entity names can quickly become awkward. The page system also keeps the dashboard readable. Instead of trying to cram an entire smart home onto one screen, users can separate information by room, function, or priority. One page might show energy use, another room temperatures, another security sensors, and another system status.

When the user presses Run on C64 inside Home Assistant, the integration sends the generated PRG file to the Ultimate and starts it. From that point, Home Assistant continues to send updated sensor values in the background. The C64 BASIC program reads the values from a reserved memory area and writes them to the screen. There are also Home Assistant buttons for stopping RAM writes and moving to the next page. These are not just convenience features. Since the integration continues pushing updates while the dashboard is active, the stop control matters when the C64 is turned off, reset, or being used for something else. The page button is also useful because it allows Home Assistant automations to control what the C64 is showing without requiring someone to press keys on the machine itself.

A modern integration with old-machine constraints

The most effective part of HomeTo64 is that it respects the limitations of the Commodore 64 rather than trying to hide them. A C64 display is not well suited to dense graphs, animated cards, complex icons, or modern dashboard widgets. HomeTo64 works because it focuses on simple labelled values: entity names and current states. That sounds basic, but it is often enough. A smart home dashboard does not always need to be visually complex. For many use cases, the important question is whether a door is open, what the temperature is, whether a device is drawing power, or how much battery a sensor has left. Those values fit the C64 format surprisingly well.

The technical design also reflects those constraints. By writing sensor data directly into memory, HomeTo64 avoids needing the C64 to speak modern web protocols or handle complicated networking itself. The Ultimate provides the bridge, Home Assistant performs the integration work, and the Commodore 64 runs a program suited to its own environment. That division of labour is the reason the project feels coherent. It does not pretend the C64 is a modern client device. It uses modern hardware around the C64 to deliver data, then lets the C64 do what it can reasonably do: display structured text, respond to keys, and update a screen.

Who is it for?

HomeTo64 is clearly aimed at a specific overlap of users: people who run Home Assistant and also have access to a C64 Ultimate. That makes it a niche project, but not an obscure one in spirit. Home Assistant users often enjoy local control, unusual integrations, and repurposing devices. Retro-computing users often enjoy making older machines interact with newer systems. HomeTo64 sits directly between those two cultures. It is not likely to replace a tablet dashboard or a phone app. It is less flexible, less visual, and more dependent on a particular hardware setup. But it does not need to replace those tools. Its value is in providing another display surface, one with a distinctive interface and a strong technical identity.

There are plausible practical uses too. A C64 in a hobby room could show workshop temperatures, server status, energy consumption, or whether doors and windows are open. It could be set to cycle through pages automatically. It could act as a dedicated status display while still remaining obviously and recognisably a Commodore 64. For many users, though, the appeal will be the build itself. HomeTo64 is the kind of project people install because they want to see it work, inspect how it works, and perhaps adapt it. That is a legitimate and important part of retro computing. Some projects are valuable because they solve a problem; others are valuable because they demonstrate an unexpected connection between systems.

A good example of practical retro hacking

The strongest thing about HomeTo64 is that it is more than a visual joke. The project has a proper Home Assistant configuration flow, exposes useful controls, generates a working C64 program, and uses the Ultimate’s network capabilities to manage execution and memory updates. It has the shape of a real integration, not just a one-off demo.

It also shows how retro hardware can remain useful when paired with modern support systems. The Commodore 64 itself is not being asked to do everything. It is being used as part of a larger arrangement, with Home Assistant handling smart home logic and the Ultimate handling network access. That is a practical approach to old hardware: keep the original machine involved, but do not force it to solve problems better handled elsewhere. There is a broader lesson here for retro-computing projects. The most successful modern uses of old machines often do not try to turn them into contemporary computers. They find a task that fits the machine’s strengths and limitations. In this case, the task is a text-based status dashboard, and the C64 is well suited to that.

Verdict

HomeTo64 is a focused, well-conceived project for a very specific audience. It will appeal most to Home Assistant users who already enjoy retro hardware, and to Commodore 64 enthusiasts who like seeing the machine interact with modern systems. It is not the most efficient way to view smart home data, but it is a technically interesting and genuinely usable one. The project succeeds because it understands both sides of the equation. Home Assistant supplies the live data, configuration, and automation potential. The C64 supplies the display, the constraints, and the character of the interface. Between them, HomeTo64 creates something that feels less like a gimmick than a small but thoughtful piece of retro-modern integration. For anyone with the right hardware, it is exactly the sort of project that makes an old computer worth switching on again.

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How it works

A modern integration with old-machine constraints

Who is it for?

A good example of practical retro hacking

Verdict

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