IcePi Zero

Most FPGA boards are designed for general use . They do a little of everything, and do nothing that well. The icePi Zero was designed for retro computing. It does that and everything else is leaves to other boards in the large Raspberry Pi ecosystem.

The board designer wanted a board to run soft cpu cores. It has all that is needed for a soft core, the rest it leaves to the Raspberry Pi ecosystem. This makes for a small and inexpensive board. $64 = € 54 the same prices as the Olimex GateMate with 2 external RAMs, but Icepi has a lot more bang for the buck.

If you look at the circuitry, it is really quite beautiful. Somebody put a lot of energy into this product. And the board is open source, so if I need to I can make whatever changes I need, and produce a new board. I also very much like the FPGA he chose for this board.

It has DVI out, a fast SDRAM, two USB ports for the. keyboard and mouse, an SD card reader, and a USB port to connect to the desktop. Everything else it leaves to the Raspberry Pi ecosystem, which is easy to plug into since it has the Raspberry Pi form factor. Lattice ECP5 is an older chip, it still supports 3.3V peripherals, which is perfect for interfacing to the Raspberry Pi ecosystem: no level shifters are needed.

The designer scratched his own itch, and in the process perfectly targeted the market. There are not many trained FPGA developers, but there are a lot of software developers who want to become FPGA developers. Their first project is usually a soft CPU core. So they want a board like this. I did the same thing for my master's thesis in electrical engineering. In the process I learned that soft cores on FPGAs are so much slower than dedicated chips. For the FPGA to be competitive, it needs a much more parallel application, which is why I moved to video. processing.

While the high level design is perfect, I worry was that there will be bugs in this board. This is the first board the designer built. Since it is an open source board, a lot of experts gave him advice, but still mistakes could have been made. And indeed that happened. The first batch of boards were received on December 17th, 2025, two of the pins were reversed, and on Jan 1 2026 version 1.3 of the board was released. So if you are doing mainstream soft cpu cores you should now be fine, but for people like me who are doing something non mainstream, there is still a worry that there will be problems with the details.

Because this board is so small and simple, it is easy to modify it. There is already a pull request for a variant with an Analog. to Digital Converter (ADC).

I really like that the IcePi Zero was designed for a specific application: retro computing.