TastyWaves

A wavetable synthesizer firmware for the M-VAVE FM-1. · tastysynth.com

TastyWaves turns the FM-1 into a 12-voice wavetable synth with two oscillators per voice, a resonant filter, two envelopes, an LFO, a four-slot effects chain, an arpeggiator and two step sequencers that can play chords and counterpoint on one clock. Patches are saved on the device, and a browser tool manages them and loads your own wavetables in four common wavetable formats. The philosophy of TastyWaves is to do one thing well and in depth, focusing on intuitive performance and usability, and to provide a rich nuanced sound engine equally useful for creating pattern-based music and evolving soundscapes. We aim to be the definitive wavetable synth on the FM-1.

Version 1.0.1. Tested on the FM-1 against docs/DEVICE-TEST-PLAN.md. It is free software (GPL-3.0), built on Dinghy, which is built on Felucca and SLOOP. See Credits.

Contents

• Features
• Install
• Playing it
• The pages
• Arpeggiator and sequencers
• Patches
• The web tool: your own wavetables, patch library
• MIDI and USB audio
• Compatibility
• Build from source
• Credits and licence

Features

Install

In your browser (easiest). Open tastysynth.com/tool in Chrome or Edge, plug the FM-1 in by USB, switch it on and press Install on the FM-1. It takes about a minute; keep the page open and the cable in. Updating TastyWaves keeps your saved patches and wavetables.

Or download the firmware: tastywaves-1.0.1.fwsc (all versions on the Releases page), for any FM-1 installer that takes a .fwsc file, or the manual install below.

If something goes wrong: hold OCT- while switching the FM-1 on. It starts in the USB rescue (no sound, only the updater), and either install works from there. A firmware that crashes twice at boot lands there by itself.

Going back: the FM-1 Firmware Hub installs the official firmware, or any other, over the same USB update path. Another firmware erases TastyWaves' patches and user wavetables: back them up with the web tool first (Backup all, and Save on each table slot), and restore them after you come back.

Manual install

You need a computer with Python 3.

1. Download tastywaves-1.0.1.fwsc (above).

2. Get the installer (this repository) and its two Python packages:

   git clone https://github.com/marksweiss/tastywaves.git
   cd tastywaves
   python3 -m venv .venv && .venv/bin/pip install mido python-rtmidi
   

3. Plug in the FM-1, switch it on, and install:

   tools/install_fw.sh ~/Downloads/tastywaves-1.0.1.fwsc
   

   It shows what runs on the FM-1, asks before it writes, and checks the result after the FM-1 restarts. tools/install_fw.sh --info shows what is installed.

Playing it

The four knobs under the screen always set the four values shown at the top of the page you're on. A page button opens its page; pressing it again steps through the page's tabs.

The line above the patch name shows the page and tab, the voices in use (V 3/12, an L when LATCH is on) and the CPU load.

The pages

	EDIT: OSC1 and OSC2 (position, semitone, fine, level; the wave drawn as it plays, BEND included), MIX (sub, noise, BEND and where it goes, the levels), FILTER (cutoff, resonance, mode, key tracking, with the response curve)
	MIX: the four levels and BEND on a sine, with the oscillators it acts on
	ENV: AMP and MOD envelopes, drawn; MOD> sets what the MOD envelope moves (cutoff, position, BEND) and the curve
	LFO: shape and rate, to position and pitch (set 1) or cutoff and amplitude (set 2)
	FX: four slots in series, each a TYPE with two values and a MIX. Delay and reverb take one slot each
	SEL: VOICE (mode, glide, bend range, quality), CONTROL (mod wheel, aftertouch, velocity routes), OUTPUT (volume, drive, velocity to cutoff)
	GLO: SETUP picks the HOME look (waterfall, spectrum, minimal); INFO shows the version, the highest CPU load and any audio drops

Arpeggiator and sequencers

The arpeggiator. Hold ARP to switch it on (HOLD ARP: ON), then hold notes. Press PLAY for LATCH and let go: the arpeggio keeps playing while you turn knobs. Press ARP to set MODE, RATE, OCT, GATE (set 1) and SWING, TEMPO (set 2).

Recording a sequence.

1. Press SEQ to open its page (SEQ1, SEQ2 and LANE tabs; press SEQ again to step through them).
2. On the SEQ1 or SEQ2 tab, press REC. Each key you play is a step; PLAY enters a rest, SEQ ties the step before. Press REC again to finish (or stop at 32 steps).
3. Hold SEQ to switch the sequencer on, then press PLAY. The status row on every SEQ tab shows HOLD SEQ: ON / OFF and PLAY: PLAYING / STOPPED.
4. Hold a key to transpose: the pattern moves by that key minus C4. LATCH a key to keep it transposed.

Two sequences. SEQ1 and SEQ2 share the tempo and PLAY, and start together. Each has its own RATE, GATE and SWING (set 1) and CHORD, ARP, OCT and LEVEL (set 2), so SEQ2 can run at 1/8 against SEQ1's 1/16, or arpeggiate chords under a plain melody. LEVEL balances them; the mix is soft-clipped, so thick textures stay clean.

Chords. CHORD makes every step play a chord on its note: a fixed shape (MAJ, MIN, 7, MAJ7, MIN7, SUS4) or HELD, the shape of the keys you hold (the lowest one is the root). The chord tab draws it on a keyboard, the root in amber. With the pattern's ARP on, each step lasts a beat and the arpeggiator plays its chord at RATE.

The modulation lane. The LANE tab holds one value per step of SEQ1. TARGET picks what it moves (position, cutoff, BEND, drive), DEPTH how far, GLIDE whether it slides between steps. SELECT picks the step and the fourth knob sets its value.

With external MIDI clock the arpeggiator and both sequences follow it; MIDI Start restarts them on the beat.

Patches

Loading. Turn PRESETS: the 8 factory patches come first, then your saved ones (U01 to U32).

Saving. The SAVE button lights when the sound differs from the patch it came from.

• Press SAVE: a user patch is saved over itself; a factory patch goes to the first free number.
• Hold SAVE and turn PRESETS to pick another number (a number in use asks first: press SAVE again).
• Hold SAVE for 2 seconds on a user patch to delete it (press SAVE again to confirm).

A patch holds every sound setting, the arpeggiator settings, both sequences with their settings, and the modulation lane. ARP, SEQ and the bypass are performance switches: changing patches doesn't stop a running sequence. The patch store holds about 32 patches without sequences and fewer with long ones; SAVE says STORE FULL when it is.

The web tool: your own wavetables, patch library

A page in your browser that talks to the FM-1 over USB-MIDI: tastysynth.com/tool (or tools/web_tool.sh in this repository, at http://localhost:8000). Everything runs in the page; nothing is uploaded anywhere. Use Chrome or Edge (Safari has no Web MIDI), press Connect to MIDI and allow SysEx.

• Install: puts the TastyWaves release bundled with the page on the FM-1 (see Install).

• Wavetables: drop a wavetable WAV (Serum, WaveEdit, Ableton) or a Surge .wt file, check the preview and send it to one of the 8 user slots. ALGORITHM lists it after the factory tables. Save a slot to a .vwt file to keep it.

• Patches: one list in PRESETS order. Rename, reorder, delete, and back up all your patches to a JSON file (both sequences included); restore puts them back.

tools/web/README.md has the details, and tools/fm1_wavetable.py does the same conversion on the command line.

MIDI and USB audio

• In: notes with velocity, pitch bend, channel aftertouch, mod wheel (CC 1), MIDI clock and Start, and a CC map for most sound parameters (firmware/src/patch.h, patch_cc). All Notes Off and All Sound Off release everything, latched notes included.
• Out: the notes you play on the keys.
• USB audio: the FM-1 appears as a stereo audio input; record it in any DAW without a cable.

Compatibility

TastyWaves reads only its own patches and wavetables. It does not read projects, patches or samples saved by other FM-1 firmwares, the official one included: save or back up what you keep in another firmware before switching. The other way round, installing another firmware erases TastyWaves' patches and user wavetables: back them up with the web tool first, and restore them when you come back. Its FM-1 identity is FM-1_937.

Build from source

You need Linux on x86-64, or macOS or Windows with Docker (the build runs the chip's toolchain in a linux/amd64 container by itself), plus Python 3 and uv.

tools/install.sh        # once: a venv, JieLi's toolchain, three files of the JieLi AC79 SDK; then a build and a host test
./build.sh              # -> build/tastywaves.fwsc
./build.sh --release 1.0.1    # -> build/tastywaves-1.0.1.fwsc
tools/web_release.sh 1.0.1    # bundle it with the web tool (its Install button, GitHub Pages)
tools/install_fw.sh     # install build/tastywaves.fwsc on the connected FM-1

The release process, step by step, and what every script does: tools/README.md.

The build refuses what would break the FM-1: a 64-bit division, a call into the chip ROM, too much RAM, a hardware register touched outside firmware/hal/.

Host mode runs the same firmware on your computer, with no FM-1: a script presses keys and turns knobs; out come the sound as a WAV and the screen as images. Every screenshot here was made that way.

tests/run_host.sh       # -> build/host/tastywaves.wav and screen PNGs
tests/run_panel.sh      # the panel; tests/run_*.sh are the test suites

Where to read next: docs/CODEMAP.md (the code), docs/RULES.md (the chip's rules: integers only, the audio interrupt's budget), docs/API.md (the platform), and the design notes: WAVETABLE_DESIGN, SYNTH-DESIGN, ARP-SEQ-DESIGN, EFFECTS-DESIGN, PATCH-STORAGE-DESIGN, UI-DESIGN, UPLOAD-DESIGN.

Credits and licence

TastyWaves is by Mark Weiss (@marksweiss), written with Claude (Anthropic). It stands on:

• Dinghy by zvenson: the smallest FM-1 firmware to build on, with host mode and the build checks. TastyWaves started as a copy of it.
• Felucca by Leo Kuroshita (Hügelton Instruments): the platform, the update loader, USB, the installer.
• SLOOP by isod89: Felucca's platform as Dinghy carries it.
• The Spleen fonts by Frederic Cambus (BSD 2-Clause).

GPL-3.0-only: see LICENSE, and LICENSING.md for who made which part. "M-VAVE" and "FM-1" belong to their owners; TastyWaves is not made or endorsed by them.