Jonathan Pallant's Neotron Pico Turns the Raspberry Pi Pico Into a Full-Size ATX PC Motherboard
Based on the earlier Neotron 32, the Neotron Pico is an RP2040 home computer straight from the '80s but compatible with modern cases.
Embedded Rust developer Jonathan Pallant is taking the popular Raspberry Pi Pico microcontroller board in a new direction: a simplified home computer, complete with a motherboard compatible with ATX cases.
Released earlier this year, the RP2040-powered Raspberry Pi Pico has been a stellar success. Despite being designed primarily for embedded microcontroller applications, it's found a home in a range of unusual projects — like a visual synthesiser, an interactive MicroPython-based computer for your desk, another for your pocket, an emulated BBC Micro, an emulated 80186 PC, and even a Nintendo Entertainment System.
Pallant's Neotron Pico, however, is different. It's bigger, for a start, and it builds on an earlier project to turn an Arm Cortex-M4 microcontroller into a home computer straight from the 1980s: the Neotron 32.
"The Neotron Pico is based around the idea of the Neotron-32," Pallant explains, "but using a low-cost Raspberry Pi Pico instead of a Texas Instruments Tiva-C Launchpad. It also stretches out to full micro-ATX size, and adds more expansion slots so that you can easily design and add your own peripherals."
Designed to mimic an ATX PC motherboard, the Neotron Pico hosts a Raspberry Pi Pico and expands it considerably. The programmable input/output (PIO) state machines, a key feature of the Raspberry Pi Pico's RP2040 microcontroller, are used to generate 12-bit Super VGA (SVGA) video and 16-bit digital audio at 48kHz.
For peripherals, the board includes I2C and SPI buses, brought out to a series of expansion slots mimicking the PCI Express slots of a modern PC motherboard. The first expansion address is home to an STMicro STM32F031-based Board Management Controller (BMC), the second an SD Card storage device, and the remaining addresses powering physical slots on the motherboard.
"The Neotron Pico is designed to run the Neotron OS — a CP/M- or MS-DOS-alike OS written in Rust," Pallant explains. "But, being open-hardware, you can program your Neotron Pico to do pretty much anything."
More details on the project, including design files, are available on the Neotron Pico GitHub repository under the Creative Commons Attribution-ShareAlike 4.0 International License. Information on the larger Neotron family, meanwhile, can be found in the Neotron Book.