PD-64 powers – A new PD-64 board turns the Commodore 64’s old-school dual-voltage requirement into a modern USB-PD setup, shrinking the power supply by offloading bulk work to a USB-PD wall adapter. It asks for 12 VDC, generates the C64’s needed 5 VDC and inverted 9 VAC usin
The Commodore 64 has a power requirement that feels oddly stubborn in 2026: it needs both 5 VDC and 9 VAC. For decades. the usual route has been an iron-core transformer—stepping down whatever the wall was already providing. whether that meant 220 V or 115 V. 50 Hz or 60 Hz—just to get the right low-voltage AC into the machine.
That tradition is being challenged by [Side Projects Lab] with a new build called the PD-64. Instead of building a bulky transformer inside the power unit, the PD-64 sits right on the C64’s power port and stays extremely small, with part of the heavy lifting pushed outward to a USB-PD wall wart.
The PD-64 requests 12 VDC. From there, it steps down to 5 VDC using a standard buck converter. The more unusual part is how it generates the C64’s 9 VAC. which needs to be inverted and produced as a specific waveform. [Side Projects Lab] handles the tricky requirement by chopping the 12 VDC line into a 500 kHz signal and running it through a tiny 5:6 ferrite transformer.
After that, the transformed output is rectified to 13.6 VDC. That voltage then powers a class-D audio amplifier, which produces the 9 V peak-to-peak, zero-DC-offset signal the C64 needs.
The project also makes it easier for other enthusiasts to build their own rather than treat the design like a closed experiment. [Side Projects Lab] has released FreeCAD files for the case and STL files under a BY-CC-ND 4.0 license. and a circuit diagram is available for the electrical design. If you don’t want to design your own PCB, finished versions are planned for sale by [sideprojectslab].
For anyone trying to keep the C64’s identity while updating its weak spots, [Side Projects Lab] previously hacked together HDMI output for the iconic computer, too—another step toward dragging the machine into the modern era.
Commodore 64 C64 PD-64 USB-PD power supply 5 VDC 9 VAC buck converter ferrite transformer class-D audio amplifier FreeCAD STL HDMI mod