Pineapple ONE

Open source 32 bit RISC-V CPU that you can make at home


Welcome! Pineapple ONE is a functioning (macro) processor, that is based on an open-source architecture RISC-V. This architecture is becoming very popular these days, and it is well, open-source, so we chose to build a cpu only out of discrete, off-the-shelf components. You heard it right, there is no FPGA nor any microcontroller, there are just logic gates and memories. Our goal is to prove that designing a “modern” CPU isn’t that hard, so we have released our schematics and made it open source as well. You can check out our GitHub repository for more information. If there would be enough interest, maybe we could make a DIY kit, so anybody interested with soldering skills would be able to make their own Pineapple ONE*!

* “Pineapple ONE” is a temporary name and could be changed later due to legal reasons.

What have we done so far

Filip Szkandera spent two years designing and building a 32bit CPU utilising the RISC-V architecture. His CPU supports a RV32I standard, so it is compatible with available compilers. It runs at 500 kHz, has a 512 kB program memory and 512 kB RAM. It also features a simple B&W VGA card with resolution of 200x150 px, so we can connect an external monitor and display some simple graphics. He created a simple shell program, that let users interact with the CPU via a keyboard connected to one of the input ports. He made a prototype first, where all the necessary features were tested and debugged and then optimised it to a modular CPU in a tower-like structure. He wanted to turn this into a community project, so anybody who is interested can contribute, or build their own. Now it is time to see how far we can get it together as a community.

How you can contribute

The current prototype that Filip made is not 100% reliable and kind of slow. To (maybe) turn is into a kit of some sort, these issues would need to be resolved and maybe some additional features added - maybe some audio card, native PS/2 keyboard support or a better VGA card - possibilities are endless. If you want to contribute, you can help with schematics, designing PCBs, creating new modules, software, website(s) or literally anything else, it does not need to be CPU related at all. Feel free to join our discord server to discuss your ideas, or just hang out there if you feel like :).


About us

Filip Szkandera

Student of Higher School and Secondary School of Electrotechnical Engineering in Olomouc, Czech Republic. Nineteen years old.
Filip Szkandera

Other contributors:

Name Email Twitter
Martin Prochazka -
Tadeas Frycak @TFrycak
If you contributed to this project, feel free to add yourself here as well!