Zeus LT

by Amigastyle

A multi-function interface board for the Commodore 64

$339 raised

of $1 goal

Funded! Order Below

Product Choices


Zeus LT With a Zion F Multi-Port Adapter Board

Room to grow. The Zion F adapter board includes three unused D-sub connectors for future expansion and a female pass-through cartridge slot for when Zeus LT is not in use. Includes one 15-pin D-sub connector cable. Onboard transformer is for 110 V.


Zeus LT Board

One Zeus LT board (with a 110 V transformer)


Recent Updates

As Featured In

Hackster News

"The Zeus LT multi-function interface board plugs into the C64's cartridge slot via a Zion adapter and allows users to control home automation systems, design/test/debug IoT devices, develop retro gaming hardware/software, and more."

PCBWay Community Blog

"The Zeus LT adds... eight inputs for sensors, four outputs controlled by relays, four outputs controlled by TRIACs, four signaling LEDs connected to the relay outputs, a single power-on LED and a beeper attached to the first relay output."

The Hackability of an Arduino With the Retro Swagger of a C64

Some people are excited about single-board computers (SBCs) that fit inside USB ports or whatever. Which is cool and all, but some of us prefer the sturdy beige majesty of a Commodore 64. Powered by eight bits of warm nostalgia and decorated with shiny keycaps that go all the way down, your beloved C64 is now good for more than just binging on Jumpman Junior (assuming you can find the floppies).

Remember that port on the back of your Commodore 64? The one you never used? Well we think it’s about time you plugged something into that port. Specifically, we recommend a Zion adapter connected to one or more Zeus LT expansion boards. Together, these two boards open up a world of possibilities:

  • Give your Commodore 64 dominion over your home automation system by connecting it to lights, cameras, sensors, automatic locks, motors, and just about any 220 V appliance. It is highly unlikely to leverage targeted marketing strategies to monetize whatever data it might gather in the process...
  • Design, test, and debug Internet-of-Things (IoT) solutions while using a keyboard that doesn't suck.
  • Develop innovative retro-gaming hardware and software that brings motion control, sensor networks, computer vision, and other "real world" input and output to the glorious world of 8-bit entertainment.
  • Learn or teach basic electronics—and BASIC programming—using a familiar, trusted platform that you can understand fully but that can (still) handle whatever computation might be required.
  • Look good doing it.

Features & Specifications

To make the magic happen, you will need a Zion adapter board and at least one Zeus LT interface board. Through this campaign, we are offering bundles that include one, two, three, or four Zeus LT boards and a corresponding number of D-sub connector cables. Finally, and perhaps most importantly, the design files for all three boards—Zeus LT, Zion LT, and Zion F—will be published online. We’re looking to do everything we can to make this a community project, to help you learn from it, and to help it learn from you!

Zion Adapter Board

Zion is a simple but essential interface between your Commodore 64 and your Zeus LT. It comes in two versions and includes the following:

Zion LTZion F
Exposed male edge connector for C64 expansion port
Reset button
15-pin D-sub connectors for Zeus LT boards14
Female pass-through cartridge slot (for when Zeus LT is not in use)

Zeus LT Interface Board

The Zeus LT adds external I/O support to your Commodore 64. It includes:

  • A single 15-pin D-sub connector for interfacing with the Zion adapter board
  • 8 inputs for sensors
  • 4 outputs controlled by relays
  • 4 outputs controlled by TRIACs
  • 4 signaling LEDs connected to the relay outputs
  • A single power-on LED
  • A beeper attached to the first relay output. (Don't worry, you can disable it.)

Zeus LT Output Specifications

Output ID01, 02, 03, 0405, 06, 07, 08
Type of OutputRelayTRIAC
Operating Voltage0-250 V AC, 0-100 V DC220 V AC
Max Continuous Current8 A1.5-5 A
Max Power2000 W250 W

They Call it BASIC for a Reason

Even if it doesn’t bring back fond memories of your first, halting steps across the plush living room carpet of computer programming, BASIC is nonetheless intuitive and easy to pick up. If you want to learn more about BASIC programming, we recommend this Two-Bit History post by Sinclair Target. Meanwhile, consider the LED sequence shown in the video above. That was driven by the following six lines of code:

No, You Don’t Have to Save Your Code on a Floppy

It turns out, there are a lot of people who love their C64s, and some of those people make cool stuff. The image below shows an SDIECplug, which is an open source device similar to the SD2IEC. Your Commodore 64 can use either of these devices to read from and write to modern flash memory cards. The smallest and cheapest such card has plenty of room for all of the BASIC programs you’re every going to write.

Of course, you certainly can save your code on a floppy. And if you’re lucky enough to have a 1541 tucked away in a closet somewhere, why wouldn’t you? (Don’t forget, all you need is a hole punch to double the storage capacity of those single-sided floppies!)

While you’re looking through your closets, keep your eyes peeled for other old hardware:

  • Any television or monitor that accepts composite input will work as a display for your Commodore 64, though you will need to find, purchase, or make an appropriate A/V cable
  • The Zion F has a pass-through slot so you can insert cartridges and other expansion modules, without removing the adapter board, as long as your Zeus LT is idle
  • Like the villain in some old movie, you can now use that joystick to control the real world: adjust a thermostat, rotate a security camera, dim the lights, lower the blinds, or route power to your smoke machine.

Support & Documentation

Zeus LT is open hardware, and we will publish all design files by the time we are ready to start shipping out completed boards. Those boards will come with a printed quick-start guide. Full documentation will be available online, as will a repository of sample code that covers various application of Zeus LT. We will also set up a technical support website and a customer forum before the end of the campaign. Meanwhile, you can reach us using Crowd Supply’s Ask a technical question form.

Manufacturing Plan

Zeus LT has been through three prototype runs, and the Zion F adapter board has been through one. The latest revisions of both designs are working at 100%. We have finalized the Zeus LT, Zion F, and Zion LT BOMs and identified our manufacturing partners, which come highly recommended by several acquaintances who have worked with them in the past. We will personally test all boards before shipping them out to backers.

Fulfillment & Logistics

Once we have tested and verified all units, the entire batch will be sent to the US for distribution to backers via Crowd Supply’s fulfillment services. Delivery within the US is included in the listed price, while delivery outside the US will incur the international surcharge specified for the relevant pledge level. Deliveries to EU countries, Switzerland, Australia, and Canada will have VAT and customs duties paid in advance, so backers in these countries will have no need to deal with Customs.

Risks & Challenges

Our greatest challenge at the moment is the COVID-19 pandemic, which continues to exacerbate typical manufacturing risks such as component shortages and delayed shipments. To help combat this, we are ordering some parts preemptively and have identified multiple providers capable of sourcing the others. We have also found several alternative manufacturers.



I'm a big fan of Commodore 64 computers. I bought my first in 1984, and now I own several, along with a collection of Amiga computers. That fascination, along with an interest in hardware and software, inspired me to design cartridges and various accessories to extend the usability of the Commodore 64.

Aleksandar Marić

See Also

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