Pineapple ONE: open-source 32 bit RISC-V CPU that you can make at home (pineapple-one.github.io)

Article summary

The Pineapple ONE is a 32-bit RISC-V CPU made from discrete, off-the-shelf components without using FPGAs or microcontrollers. It runs at 500 kHz and has 512 kB of program memory and RAM. The project's goal is to show that designing a modern CPU is not that hard and to create a community-driven project. The CPU's design and schematics are open-source and available on GitHub.

Main themes

• RISC-V CPU design
• Discrete component implementation
• Open-source hardware
• CPU performance
• Modern CPU design
• Community-driven projects

What commenters say

• The use of discrete logic gates and EEPROMs makes the project interesting and feasible, but also limited in terms of performance.
• Implementing a full RISC-V instruction set with discrete components is unlikely and may require compromises.
• Microcode can be used to implement complex instructions, but it comes at the cost of performance.
• The project's claim of being a 'modern' CPU is disputed, with some arguing that it lacks key features such as privilege levels and virtual memory support.
• The use of discrete components is not a modern approach to CPU design, but rather a nostalgic or educational one.
• The project's openness and community-driven approach are seen as valuable, regardless of its performance or feature set.
• The distinction between an FPGA and a discrete component implementation is blurred, with some arguing that the latter can be seen as a form of 'poor man's FPGA'.