10-Inspirations.md

YAPC - Inspirations

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(from http://www.network-science.de/ascii/, "small" font)

From the release of the Raspbery Pi Pico in January 2021 till now (december 2023), there are many projects around VGA and DVI/HDMI screen output, surrounded by a more ancient wave of other retro computers using other micro-controllers and/or 8 or 16 bits CPUs, mainly because old 8 bits computers are either too old or too expensive compared to what Arduino, ESP32 & al. cost and are able to achieve.

Here's now a list of projects that are related to this:

Pico stuff

VGA scanvideo from pico-extras by the Raspberry Pi Foundation

• For me, this is the base for all of this!
• https://github.com/raspberrypi/pico-extras/tree/master/src/common/pico_scanvideo

VGA demo board by Pimoroni

• Implementation of reference design from chapter 3 of https://datasheets.raspberrypi.com/rp2040/hardware-design-with-rp2040.pdf
• https://shop.pimoroni.com/products/pimoroni-pico-vga-demo-base

First thread about VGA on the Raspberry Pi forums

• That's what interested me in this stuff, after I bought a couple Picos in early 2021 and then the VGA demo board
• https://forums.raspberrypi.com/viewtopic.php?p=1829133

HAGL by tuupola

• Generic library for bitmap graphics, originally written with I²C or SPI LCD panels in mind
• https://github.com/tuupola/hagl/
• Uses Unicode fonts in FONTX format, cf. http://elm-chan.org/docs/dosv/fontx_e.html
• Can be extended to new types of screens via an Hardware Abstraction Layer (HAL), cf. below

HAGL HAL for Pico VGA board by CHiPs44 (it’s me ;-))

• https://github.com/CHiPs44/hagl_pico_vgaboard
• Framebuffer based
• For the VGA demo board
• Implements many VGA modes from http://tinyvga.com/vga-timing and several other sources
• Still buggy in terms of stability when using some modes and/or framebuffer manipulation techniques
• Has a rather complete demo

pshell by lurk101

• Serial accessible shell
• With vi (from busybox)
• And C compiler generating ARM M0+ code
• https://github.com/lurk101/pshell
• Uses internal flash by default with LittleFS, SD card support for VGA board

pt52 by DarkElevenAngel

• VT-52 compatible serial terminal with vi editor that uses the VGA demo board
• https://gitlab.com/DarkElvenAngel/pt52
• pt52-lua is on the way, cf. https://gitlab.com/DarkElvenAngel/pt52-lua

PicoVGA by Miroslav Nemecek

• https://github.com/Panda381/PicoVGA
• RGB332, not scanvideo based, uses its own DAC and PIO
• With sprites & layers
• See also https://github.com/Panda381/PicoLibSDK

MCUME by Jean-Marc Harvengt

• https://github.com/Jean-MarcHarvengt/MCUME
• MCUME includes several emulators of 8 bits computers for several MCUs
• VGA for the Pico is based on PicoVGA

PicoSystem from Pimoroni

• Game console on a tiny 240x240 LCD, with a C (C++?) SDK
• https://shop.pimoroni.com/products/picosystem
• https://github.com/pimoroni/picosystem
• Can run yocto-8 and some Pico-8 games

PicoBB by Memotech-Bill & others

• https://github.com/Memotech-Bill/PicoBB
• BBC Basic implementation for the VGA board
• IIRC, every function from the SDK is accessible and automatically included!

Picocomputer 6502 by Rumbledethumps

• https://github.com/picocomputer
• 8 Mhz 65C02 as CPU + 2 supporting Picos for VGA and I/O
• Interesting concept of the PIX to handle communication between the Picos via PIO
• Back to an publicly open source project after a blackout period of time
• Great features on "GPU" side: 3 layers (bitmap, tilemap, text) with scrolling and "affine" sprites
• 8 channels PSG with waveforms and ADSR parameters (january 2024)

RP2040-PICO-PC by Olimex

• https://www.olimex.com/Products/MicroPython/RP2040-PICO-PC/open-source-hardware
• "Motherboard" is only 12€ (without Pico or Pico W)!
• "RP2040-PICO-PC allows RP2040-PICO to become a computer with SD card, HDMI display, Audio, USB keyboard, Li-Po charger and battery support, UEXT connector, and I2C connector."
• DVI/HDMI instead of VGA
• GPL v3 license

PicoMiteVGA & WebMite by Geoff & others

• https://geoffg.net/picomitevga.html / https://geoffg.net/webmite.html
• https://github.com/UKTailwind/PicoMite / https://github.com/UKTailwind/PicoMiteWeb
• MMBasic seems to be great but its license is too restrictive, being open source only, not free as GPL nor permissive like MIT or BSD, see https://geoffg.net/OpenSource.html for an explanation
• Handles GPIO, I²C, SPI from BBC Basic
• WebMite has interesting ideas about networking functions (NTP, ...)

Neotron Pico by Jonathan Pallant (the JPster)

• https://github.com/Neotron-Compute/Neotron-Pico
• VGA is a 12 bits (RGB444) implementation of scanvideo to limit the amount of GPIO pins used
• Code is written in Rust (and intended as a showcase of embedded Rust)
• I/O controller is not a Pico, but there is an interesting notion of BIOS and an API to communicate via SPI (or serial ?)
• Motherboard is in micro ATX form factor and embeds several expansion connectors usable with SPI (or I²C?)

Picoputer by amen

• Emulation of Transputer nodes
• https://github.com/blackjetrock/picoputer
• https://trochilidae.blogspot.com/2021/07/stack-based-with-os-in-hardware.html
• Interesting for high speed communication between nodes using PIO
• I can't say I understand all the concepts around this ;-)

Pico-56 by Troy Schrapel

• "The HBC-56 (65C02/TMS9918A/AY-3-8910 retro computer) fully emulated on a Raspberry Pi Pico"
• 12 bits VGA with homemade PIO (not scanvideo based)
• PS/2 keyboard, 2 NES ports,
• 65C02 CPU, 65C22 VIA, TMS9918A VDP, Dual AY-3-8910 PSGs, Dual NES controller inputs, PS/2 keyboard input, 96KB Banked RAM/ROM
• cf. https://github.com/visrealm/pico-56/
• MIT license
• can be repurposed to be whatever computer, see "episodes" for examples

Neo6502 by OLIMEX

• 65C02 with RP2040 managing RAM and clock, HDMI output, USB keyboard
• https://github.com/OLIMEX/Neo6502
• Olimex sells it as Open Source Hardware, cf. https://www.olimex.com/Products/Retro-Computers/Neo6502/open-source-hardware
• Prototype as of August 2023
• Apple //e, ][+ & Oric Atmos emulator: https://github.com/vsladkov/reload-emulator

PicoVision by Pimoroni

• Dual RP2040 (Pico W + RP2040 on board), DVI (HDMI), 2x8MB PSRAM (!)
• Shop: https://shop.pimoroni.com/products/picovision?variant=41048911904851
• Code: https://github.com/pimoroni/picovision, MIT license

pico-vdp by Patrick Alastair

• https://github.com/alastairpatrick/pico-vdp
• Raspberry Pi Pico based Video Display Processor RC2014 Board with video and audio output, keyboard and mouse input
• Seems to be stalled in the "sprite" branch since 2022
• C, GPL 3.0

Non pico stuff

FabGL by Fabrizio Di Vittorio

• C++ graphics library for ESP32 with 64 colors VGA output supporting PS/2 keyboard and mouse
• http://www.fabglib.org/

LVGL by the LVGL team

• Light and Versatile Graphic Library
• https://lvgl.io/
• License: MIT
• Language: C99 (C++ compatible)
• Very complete / complex
• Ported to Pico / RP2040 with LCD SPI/I²C screens in mind

Pico-8 and TIC-80 fantasy consoles

• https://www.lexaloffle.com/pico-8.php
• Not open source, but great, see games like Celeste https://www.lexaloffle.com/bbs/?tid=2145 for example!
• Both use Lua as default language
• https://github.com/nesbox/TIC-80
• Open source
• Uses Lua, too
• Both include sprite / map / sound / code editors
• The virtual resources are limited (low resolution, 16 colors, 4 channel sound, ...), but demand much more resources on the host, see https://github.com/yocto-8/yocto-8 for an example of a Pico-8 player for RP2040 and the difficulties encountered

Agon light 2 from the Byte Attic

• Modern Z80 implementation with a micro-controller for video and I/O
• https://github.com/TheByteAttic/AgonLight
• https://www.thebyteattic.com/
• No Pico inside, but it’s representative of some of the goals of this project
• Olimex sells it as Open Source Hardware, cf. https://www.olimex.com/Products/Retro-Computers/AgonLight2/open-source-hardware
• Runs BBC Basic

RC2014 ecosystem

• Z80 based modular system
• https://rc2014.co.uk/
• Runs either homebrew, Microsoft BASIC, CP/M or MSX software
• Can use a Pico VGA terminal, cf. https://rc2014.co.uk/modules/pi-pico-vga-terminal/