C1ZZL3 Gnarly

C1ZZL3 Gnarly is a dual-oscillator phase-distortion synth card for the Music Thing Modular Workshop Computer.

Gnarly is the most complexVersion of C1ZZL3. It keeps the Web MIDI sound-preset workflow from the advanced C1ZZL3 experiments, but removes the Turing machine panel mode so the hardware controls can focus on oscillator editing, recipe wave banks, ring modulation, and noise/grit.

For the user-facing card guide, see:

CARD_README.md

Status

This folder contains the stable Gnarly card 101 build.

release: 101 / Gnarly protocol v11 stable
draft: false

Core C1ZZL3 remains card 84. Gnarly is prepared here as a separate card identity because its hardware behaviour is substantially different.

Firmware Builds

The standard Gnarly firmware is:

uf2/C1ZZL3_GNARLY_V11.uf2

The alternative firmware for use with an 8mu v2 controller is:

uf2/Gnarly_C1ZZL3_8mu.uf2

Flash one of these UF2 files, not both. Their SHA-256 checksums are in uf2/SHA256SUMS.txt.

What It Does

• Runs two phase-distortion oscillator lanes.
• Uses separate Amp1/Amp2, PD1/PD2, and Pitch1/Pitch2 envelopes.
• Supports named sound presets saved on the card.
• Saves either envelope-only data or full sound presets with performance settings.
• Uses four recipe wave banks for simple and CZ-like oscillator pairings.
• Reads and writes settings through the Gnarly Web MIDI Lab.
• Imports Casio CZ .syx patches through the shared C1ZZL3 Import Lab.
• Removes Turing CV, Turing pulse, and generated Turing MIDI behaviour.

Hardware Controls

Switch middle: oscillator 1 page.

• Main: shared pitch
• X: oscillator 1 phase distortion
• Y: oscillator 1 recipe slot in the selected bank

Switch up: oscillator 2 page.

• Main: oscillator 2 base interval/spread, centred at unison
• X: oscillator 2 phase distortion
• Y: oscillator 2 recipe slot in the selected bank

Switch down hold: performance and bank page.

• Main: recipe bank
• X: ring modulation
• Y: noise/grit

Recipe Banks

Bank	Sound character
1	Simple single-wave families.
2	Warmer compound pairings with double-sine support.
3	Brighter resonant/windowed pairings.
4	Odd/import-faithful CZ-style pairings for translated patches.

Each oscillator recipe slot selects one entry from the current bank. Bank 1 contains the eight plain C1ZZL3 wave families; Banks 2–4 use fixed compound recipes.

Slot	Bank 1: simple waves	Bank 2: warm compounds	Bank 3: resonant compounds	Bank 4: CZ-style pairings
1	Saw	Double sine + Saw	Resonant saw window + Saw	Saw pulse + Double sine
2	Square	Double sine + Square	Resonant triangle window + Square	Resonant triangle window + Double sine
3	Narrow pulse	Saw + Double sine	Resonant trapezoid window + Narrow pulse	Saw pulse + Narrow pulse
4	Double sine	Square + Double sine	Resonant saw window + Saw pulse	Resonant trapezoid window + Double sine
5	Saw pulse	Narrow pulse + Double sine	Resonant triangle window + Saw pulse	Resonant saw window + Saw pulse
6	Resonant saw window	Saw pulse + Double sine	Resonant trapezoid window + Saw pulse	Narrow pulse + Resonant trapezoid window
7	Resonant triangle window	Resonant triangle window + Double sine	Resonant saw window + Narrow pulse	Square + Resonant saw window
8	Resonant trapezoid window	Resonant trapezoid window + Double sine	Resonant trapezoid window + Square	Resonant triangle window + Narrow pulse

These are not equal 50/50 blends. Each recipe leans toward its first waveform, with the second waveform mixed in at a fixed amount chosen in the firmware. That is why some pairings feel like a coloured version of one family rather than a completely even hybrid.

On the switch-down page, LEDs 1 and 2 show the selected recipe bank:

• Bank 1: LEDs 1 and 2 off.
• Bank 2: LED 1 on.
• Bank 3: LED 2 on.
• Bank 4: LEDs 1 and 2 on.

MIDI

Gnarly uses CC20 to CC27 as an eight-knob performance block. CC1 is also kept as oscillator 1 phase distortion so a mod wheel remains useful.

• CC1: oscillator 1 phase distortion, mod-wheel friendly.
• CC20: oscillator 1 recipe slot.
• CC21: oscillator 2 recipe slot.
• CC22: ring modulation amount.
• CC23: recipe bank.
• CC24: oscillator 2 interval/spread.
• CC25: oscillator 2 phase distortion.
• CC26: noise/grit amount.
• CC27: oscillator 1 phase distortion, for eight-knob controllers.

The C1ZZL3 Envelope Lab has a hidden Developer-mode MIDI CC Test Suite for checking these messages without a hardware controller. It sends individual CC values, a neutral reset, and sweep tests through the selected Web MIDI output.

If You Have An 8mu

Gnarly_C1ZZL3_8mu.uf2 is an alternative Gnarly firmware that exposes the envelope lanes on a Music Thing 8mu v2. It retains the same Gnarly sound engine and Web MIDI editor, but receives its controls from the 8mu instead of using only the editor.

The alternative source is self-contained in 8mu/, so it can be developed without changing the standard Gnarly source in this folder. The 8mu bank files are in 8mu_banks/; import them one at a time with the 16n Faderbank editor. See 8mu_banks/README.md for the exact import and control guide.

• Bank 1 controls the regular Gnarly performance parameters. Its A--D buttons send unused CCs 124--127 and therefore do not play notes.
• Banks 2--7 edit stages 1--8 of Amp1, Amp2, PD1, PD2, Pitch1, and Pitch2.
• Bank 8 selects the editable custom envelope slot and sets the six lane depths plus master depth.
• In a lane bank, Buttons A/B select level/time, C saves, and D reverts.

Only saved custom sound-preset slots are editable; factory envelopes remain read-only. Gesture mappings are intentionally disabled. The 8mu control path, save/revert, persistence, and factory-envelope protection have been hardware validated.

Web MIDI Editor

Hosted editor path after Workshop deployment:

https://computer.musicthing.co.uk/programs/101-gnarly-c1zzl3/web/index.html

Local editor from this release folder:

python3 -m http.server 5177 --directory web

Open:

http://localhost:5177

Use Chrome or another browser with Web MIDI and SysEx support. When Web MIDI connects, the editor automatically checks card settings and saved envelope slots so the detected firmware type is shown without requiring a manual read first.

C1ZZL3 Import Lab

Hosted import lab path after Workshop deployment:

https://computer.musicthing.co.uk/programs/101-gnarly-c1zzl3/web/import/index.html

Local import lab from this release folder:

python3 -m http.server 5178 --directory web/import

Open:

http://localhost:5178

Use this page to decode Casio CZ .syx patches into C1ZZL3 drafts with separate oscillator envelopes, pitch lanes, oscillator wave choices, performance values, and recipe-bank-compatible settings.

Build

cmake -S . -B build -DPICO_NO_PICOTOOL=1
cmake --build build -j2

The build creates:

build/C1ZZL3_GNARLY_V11.uf2

To build the alternative 8mu firmware:

cmake -S 8mu -B build-8mu -DPICO_NO_PICOTOOL=1
cmake --build build-8mu -j2

This creates build-8mu/Gnarly_C1ZZL3_8mu.uf2.

License Notes

This project is released under the MIT License. The included computercard.h hardware helper is ComputerCard by Chris Johnson and is also MIT licensed; keep its MIT notice present when copying firmware files into releases or experiments.

USB MIDI host support includes the MIT-licensed rppicomidi files, copyright 2023 rppicomidi. Their copyright and licence notices are retained in the corresponding source files.

Firmware distribution notices

See THIRD_PARTY_NOTICES.md for dependency copyright and license texts. Keep the accompanying NOTICE.txt with each UF2 when redistributing it.