In the latest video from What’s Ken Making, Ken introduces the OtterX DIY Commander X16, a fully open-source, solder-it-yourself clone of the Commander X16 system. For those who’ve been tracking the 8-Bit Guy’s long-running Commander X16 project but held back due to the lack of a DIY option or high price tag, OtterX might just be the answer. Designed by Joe Burks (aka Wavicle), this compact, compatible alternative lets retro computing fans build their own X16-inspired system from the ground up.
You can purchase the OtterX kit from Joe’s Retro Sto’ on Tindie or dive into the design files on the OtterX GitHub.
A Compact and Capable Clone
The OtterX DIY Commander X16 isn’t just another clone—it’s thoughtfully built in a Mini-ITX form factor and includes all the core features of the X16 Developer Edition. The kit arrives with a clearly labeled PCB, controller ports, capacitors, resistors, connectors, and even Joe’s own Vera X video card and FPGA-based OPM2151 audio board.
It supports both the 6502 and 65816 CPUs, and includes a clever CPU switcher that lets you toggle between the two with a jumper. There’s also onboard flashable ROM loaded with the official X16 kernel.
Graphics and Sound: Vera and OPM
For video, OtterX uses the Vera card—originally developed for the Commander X16 by Frank van den Hoef. It handles VGA, composite, S-Video, and RGB output, and supports a range of graphics modes. The upgraded Vera X version even adds breakout headers for audio/video expansion.
Sound-wise, the OtterX replaces the now-rare Yamaha YM2151 with an FPGA-based clone called the OPM2151. It offers the same FM synthesis but is easier to source and install. It’s paired with an off-the-shelf DAC to reproduce analog audio output.
Building the System
Ken estimates the build will take around five hours for experienced hands. The interactive BOM tool makes component placement easy, and the well-labeled PCB design helps reduce errors. You’ll find two case choices below. First is the custom acrylic case offered by BitByBit Synths. The next two are downloadable 3D printable case designs for the OtterX.
For power, the OtterX uses a standard ATX connector. A compact PicoPSU works well and fits neatly in the Mini-ITX case.
Running Software and Games
The OtterX boots directly into the X16 environment and supports Commodore BASIC. It runs demos like Second Reality, X16 games such as Planet X16, and even NES ports like Super Mario Bros. thanks to its 6502 CPU. Ken shows how the OtterX handles file managers, music playback, SNES controller support, and expanded memory upgrades.
He also tests a 2MB memory expansion (included as an optional kit) that allows for more advanced programs, such as a 3D engine demo developed by a community member on the Commander X16 Discord.
Pros, Limitations, and Final Thoughts
The OtterX improves on the original Commander X16 hardware with better power isolation, EMC design, and a battery-friendly RTC. However, the compact size does mean fewer expansion slots (just one) and tighter component spacing, which might challenge novice builders.
Still, at $275 for the DIY kit—or $350 pre-assembled—the OtterX DIY Commander X16 offers great value and flexibility for anyone excited about retro computing. It’s a rewarding project with solid compatibility, vibrant community support, and impressive results.
You can also explore more at the Commander X16 website or view the official Developer Edition listing via TexElec.com.
