README from GitHub, GPL-3.0

Arcturus S6's boot screen

Arcturus S6

A Waveform Animation System for the M-VAVE FM-1. An experimental, self-playing wavetable instrument for generative, evolving soundscapes, with the sound and look of early digital machines.

Four PPG-style wavetable oscillators, no sequencer and no filter section: the movement comes from Serge-style modulators patched into the oscillators, into each other and into themselves. The engine runs natively at 12 bit and 22.05kHz on 8-bit wavetables, and the screen is a green phosphor CRT after the Fairlight CMI.

The boot screen, oscillators, wavetable, function generators, gate generators, mod matrix, reverb and disk pages

4 wavetable oscillators: 1 and 2 phase-modulate each other, A and B have wavefolders; each has a 12dB hi cut, level and pan.
13 wavetables, the last one generative (reroll it on the box); smooth or stepped scanning.
6 Serge-style function generators: rise, fall, lin / exp / log curves, cycle / gate / once, end-of-cycle gates.
2 sample-and-holds (noise or any modulator, slew) and a quadrature LFO.
4 gate generators: two square LFOs each (free or MIDI clock) into AND, NAND, OR, NOR, XOR, XNOR and NOT.
An EMS-style mod matrix and a gate matrix, feedback welcome.
21 tunings (just intonation, shruti, Bohlen-Pierce, the Carlos scales and more) with per-oscillator quantisers.
Effects: a low-rate plate reverb with freeze, a shift-register delay, a flanger, in any order.
16 named patches on a DOS-style disk page, INIT and RANDOM on the keys, a random drone at every power-on.

Quick start guide: getting around, page by page, and patch ideas (Krell, generative melodies, rhythms from logic).

Install

The easy way: the FM-1 Firmware Hub, in Chrome or Edge, installs it over USB with one click, and takes you back to the official firmware or any other the same way.

By hand: download arcturus-s6-X.Y.fwsc from the releases, then

pip3 install mido python-rtmidi                # (Windows: not needed, see below)
python3 tools/fm1_install.py arcturus-s6-X.Y.fwsc

On Windows, put the .fwsc, tools/fm1_install.py, tools/fm1_winmidi.py and tools/windows/install.bat in one folder, rename the firmware arcturus-s6.fwsc and double-click install.bat (it needs Python 3).

If it won't start: hold OCT− while switching on. That's the USB rescue: no sound, only the updater, so you can install it again or install another firmware from the hub. Installing firmware is at your own risk.

Status

Tested on one FM-1. It's an experimental instrument written by machine (Claude, by Anthropic) with human guidance: expect rough edges, and tell us about them in the issues.

Build it yourself

Arcturus S6 is built on Dinghy, so it builds the same way: Linux on x86-64 (or Docker), Python 3 with Pillow, the JieLi toolchain and three files of the JieLi AC79 SDK.

pip3 install Pillow mido python-rtmidi
tools/get_toolchain.sh
git clone --depth 1 --branch AC79NN_SDK_V1.2.1_2023-12-13 \
    https://gitee.com/Jieli-Tech/fw-AC79_AIoT_SDK.git ~/fw-AC79_AIoT_SDK
./build.sh                                     # -> build/arcturus-s6.fwsc
tests/run_host.sh tests/scripts/demo.txt       # the firmware on your computer: build/host/*.wav and screen PNGs

GitHub builds every push to main, and a tag vX.Y builds, tests and publishes a release with a build attestation. The firmware itself is firmware/src/dinghy.c and firmware/src/verb.h (the effects); the wavetables and lookup tables come from tools/gen_tables.py. Dinghy's own docs, for the platform under it: docs/API.md, docs/RULES.md, docs/MAKE-IT-YOURS.md.

Credits and licence

GPL-3.0-only: you may change and share it, and whoever gets your firmware gets its source. Details in LICENSING.md.