PicoDOS

PicoDOS is a lightweight, interactive shell operating system environment built in MicroPython for the Raspberry Pi Pico. It provides a CLI, filesystem commands, and support for running simple .psh scripts and MicroPython apps. Note: Pico# (pico sharp, psh) is an interpreted language that I've written in MicroPython. It is tailored to the Pico and supports variables, conditions, primitive types, functions, iteration, standard input/output, and light recursion. I plan on making a seperate repository to document this language.

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Features

• Interactive terminal with command history, scrolling, and editing
• Basic file system commands: DIR, CDR, DEL, RNM, MDR
• Runs custom .psh script files with an embedded interpreter
• Nano-style text editor for .txt and .psh files
• Simple games playable with joystick and buttons
• Runs on Raspberry Pi Pico with MicroPython firmware, however it can be compiled to .mpy and uf2 format to run without dependencies.
• Designed for ease of use and expandability. This repo contains its MicroPython source code. On the Pi, it's cross-compiled into .mpy binaries using mpy-cross.

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Supported Commands

Command	Description
DIR	List files and directories
CDR	Change directory
DEL	Delete a file (only .txt/.psh)
RNM	Rename a file or directory
MDR	Make a new directory
RUN	Run a .psh script
OPN -R/W	Open file in the built-in editor

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Controls

• The joystick is mainly used for navigation and gaming.
• Buttons:
  • A — the ENTER key and typically start/stop in games
  • B — goes up a directory in file explorer, also used to restart a game
  • X — exit current app or shell
  • Y — return to picoDOS home menu
• Keyboard:
  • A 4x4 matrix keypad
  • The first row is normal, all rows succeeding it have their last key reserved as a toggle button. This is similar to how SHIFT and NUMBER LOCK work on standard keyboards.

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Installation

1. Flash Raspberry Pi Pico with official MicroPython firmware.
2. Clone the repo and compile the files into .mpy binaries using the mpy-cross cross compiler.
3. If you want to take it a step further, you could inject the binaries into the MicroPython firmware and freeze it, condensing PicoDOS into a single uf2 file. Note that this would remove the ability to modify the PicoOS source files.

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Future Work

• Port picoDOS to C++ for better performance and bare-metal control
• Add multitasking and more advanced filesystem support
• Integrate more apps and network-based tools and services

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Acknowledgments

Thanks to the Raspberry Pi Foundation and MicroPython community for making embedded development accessible.

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MIT License © Satej Gandre