Konrad Beckmann's PicoCart64 Is a Raspberry Pi Pico or RP2040 Stamp-Powered Nintendo 64 Flash Cart
Designed to load homebrew software from ROM files stored on an SD card, this board is driven by the RP2040's flexible PIO blocks.
Maker Konrad Beckmann has proven that it's possible to boot a Nintendo 64 console from a Raspberry Pi Pico — and is using that knowledge to build a flash cartridge for homebrew games, based around a Solder Party RP2040 Stamp.
"When I hear people say something is not possible or highly unlikely to succeed, that motivates me," Beckmann writes of the inspiration behind the self-set challenge of using a $4 microcontroller to boot a cartridge-based games console launched in 1996. "Turns out you can use a Raspberry Pi Pico to boot homebrew on your Nintendo 64 after all!"
Knowing it's physically possible gave Beckmann the boost required to continue with a rather more elaborate project than a prototype with wires running into the Nintendo 64's cartridge slot: The PicoCart64, a custom-designed flash cartridge powered by the Solder Party RP2040 Stamp system-on-module.
"The Raspberry Pi Pico [or RP2040 Stamp] emulates a game cartridge by responding to bus requests, providing data which is fetched from the external flash," Beckmann explains of the cartridge's operation. "The IO handling is implemented using the Pico's unique PIO [Programmable Input/Output]. [The lockout chip, designed to prevent unauthorised software running on a Nintendo 64 is] running on the [RP2040's] second core. The Pico is awesome."
The flash cartridge, which holds an RP2040 Stamp module in the middle either soldered down or via FlexyPin removable mounts, includes a microSD card slot for ROM storage and a USB Type-C port for data connectivity. Inserted into the Nintendo 64's cartridge slot, it bypasses the lock-out mechanism and allows any compatible code to load and boot — running on the original Nintendo hardware, with only the cartridge access captured and emulated.
More details of the project are available on Beckmann's Twitter thread, while the — as-yet untested — KiCad board design and software source code can be found on the project's GitHub repository under an unspecified open-source license.