The Picocomputer explores retro computing and game development by removing the barrier between genuine 8-bit hardware and modern devices. It can be built entirely with through-hole components, compactly using surface mount devices, or even on a breadboard. No programming devices need to be purchased and the only component used that wasn't available in the 1980s is the $4/€4 Raspberry Pi Pico.

Learn how it works on YouTube:
https://www.youtube.com/@rumbledethumps

Read the documentation:
https://picocomputer.github.io/

This is only for building the Pi Pico software. For writing 6502 software, see the rp6502-vscode and rp6502-sdk.

Install the C/C++ toolchain for the Raspberry Pi Pico. For more information, read Getting started with the Raspberry Pi Pico.

sudo apt install cmake gcc-arm-none-eabi libnewlib-arm-none-eabi build-essential gdb-multiarch

All dependencies are submodules. The following will download the correct version of all SDKs. It will take an extremely long time to recurse the project, so do this instead:

git submodule update --init
cd src/pico-sdk
git submodule update --init
cd ../pico-extras
git submodule update --init
cd ../..

The Pi Pico VGA is also a Picoprobe for development and terminal use. Load a release build of rp6502_vga.uf2 on it with the BOOT SEL button. You can do the UF2 process with the RIA board too, or use the VGA/Picoprobe board to load it using OpenOCD.

The VSCode launch settings connect to a remote debug session. I use two terminals for the debugger and monitor. You'll also want to add a udev rule to avoid a sudo nightmare. The following are rough notes, you may need to install software which is beyond the scope of this README.

Create /etc/udev/rules.d/99-pico.rules with:

#Picoprobe
SUBSYSTEM=="usb", ATTRS{idVendor}=="2e8a", MODE="0666"

Debug terminal: (use OpenOCD 0.11)

$ openocd -f interface/picoprobe.cfg -f target/rp2040.cfg -s tcl

Monitor terminal:

$ minicom -c on -b 115200 -o -D /dev/ttyACM0

WSL (Windows Subsystem for Linux) can forward the Picoprobe to Linux:

PS> usbipd list
BUSID  DEVICE
7-4    USB Serial Device (COM6), Picoprobe

PS> usbipd wsl attach --busid 7-4

WSL needs udev started. Create /etc/wsl.conf with:

[boot]
command="service udev start"