C1ZZL3

Stable production firmware for the Cosmik C1ZZL3 Music Thing Modular Workshop Computer card.

C1ZZL3 is a dual phase-distortion synthesiser with custom Web MIDI envelopes, USB MIDI device/host support, optional Turing MIDI output, and a Turing machine mode with CV and pulse outputs.

For the user-facing card guide, see:

CARD_README.md

Stable Build

Current stable UF2:

uf2/C1ZZL3.uf2

Checksum:

12c356ad75d6d25fccab5060dbb057f1e3ed86169c2429a798c66f835825ed61

This is hardware-tested production release 1.1, promoted on 2026-07-06.

Release 1.1 works with Envelope Lab and C1ZZL3 Import Lab and includes Web MIDI PD, detune, eight waveform families, card-to-editor envelope readback, and browser CZ patch import handoff.

Current Stable Feature Set

• Phase-distortion synth voice.
• Factory envelopes plus eight protected custom envelope slots.
• Web MIDI envelope editor.
• Hosted CZ patch import workflow.
• USB MIDI device mode for DAW/browser use.
• USB MIDI host mode for class-compliant controllers.
• MIDI notes with envelope triggering.
• MIDI CC control with knob pickup handoff.
• Turing machine audio, CV, pulse, and optional MIDI note output.
• Turing CV and pulse outputs continue running in synth mode.
• Settings readback from the card into the Web MIDI editor.
• Ring, noise, MIDI channel, Turing range, and Turing MIDI settings persist.

Controls

Switch middle: synth mode.

• Main: pitch
• X: phase distortion
• Y: waveform
• CV In 1: phase-distortion modulation
• CV In 2: waveform modulation
• Pulse In 2: envelope trigger and oscillator sync

Switch down from middle: performance edit and save.

• Main: oscillator 2 detune
• X: ring modulation
• Y: noise/grit

Switch up: Turing mode.

• Main: mutation/lock
• X: sequence length, 2 to 16 steps
• Y: internal clock speed
• Pulse In 1: external clock
• CV Out 1: stepped Turing CV
• CV Out 2: smoothed Turing CV
• Pulse Out 1/2: Turing pulses

MIDI

MIDI CC controls on the selected input channel:

• CC1: phase distortion
• CC20: oscillator 2 detune
• CC21: ring modulation
• CC22: noise amount
• CC23: waveform
• CC24: Turing CV octave range, from 1 to 8 octaves

The physical knobs and MIDI CC controls share the same control values. After a CC change, the related knob must be swept through the current value before it takes over again.

Envelope Lab

Hosted editor:

https://tomwhitwell.github.io/Workshop_Computer/programs/84-cosmikc1zzl3/web/index.html

Local editor from this release folder:

python3 -m http.server 5173 --directory web

Open:

http://localhost:5173

Use Chrome or another browser with Web MIDI and SysEx support.

C1ZZL3 Import Lab

Hosted import lab:

https://tomwhitwell.github.io/Workshop_Computer/programs/84-cosmikc1zzl3/web/import/index.html

The Import Lab is included at web/import/index.html. It decodes Casio CZ .syx patches into C1ZZL3 drafts, then hands the result to Envelope Lab for final editing and sending. The navigation buttons at the top of both pages switch between the two labs.

Current Import Lab features:

• Light and dark mode toggle matching the Envelope Lab palette.
• Larger C1ZZL3 Import Lab header and a clearer guided import workflow.
• Drag-and-drop or file-picker import for Casio CZ .syx files.
• Browser-side validation, patch summary, decoded data, and draft mapping.
• Draft handoff into Envelope Lab in a new tab for final editing and card send.
• Separate import page so CZ translation and envelope editing stay distinct.

Import Lab flow:

1. Open C1ZZL3 Import Lab.
2. Drop in or choose a Casio CZ patch file.
3. Review the validation, decoded summary, warnings, and mapped draft.
4. Use Open In Envelope Lab to carry the draft into the main editor.
5. In Envelope Lab, review the result, adjust if needed, and send or save it.

How To Use The Editor

1. Pick a preset on the left, or add a custom one.
2. Choose Amplitude or Phase Distortion to focus on one lane at a time.
3. Drag points on the graph to change both level and timing.
4. Watch the point numbers. Matching numbers mean the stages are stacked at the same spot.
5. Use the tables below the graph for exact values when you want precise edits.
6. Use the action buttons on the right when you want to send, save, read, or reset.

Button quick reference:

• Load RAM: send the envelope to the card until reset.
• Load Envelope + Settings: temporarily load the selected envelope and send all current settings in one action.
• Save Envelope: store the selected custom envelope in flash.
• Delete Envelope Slot: clear the selected custom slot from card flash.
• Read Envelopes from Card: load occupied card slots into the editor without overwriting changed local drafts.
• Read Settings from Card: pull the current performance settings into the editor.
• Send Settings: send the current performance settings to the card.
• Reset Preset: restore the selected preset to its factory value.

Load RAM, Load Envelope + Settings, and Send Settings are temporary. Use Save Envelope to retain an envelope in flash. To make the current performance settings the startup baseline, move the hardware switch from middle to down and hold it until the card confirms the save.

The card can save up to eight custom envelopes. The browser can retain additional local drafts. Factory presets are not overwritten. Custom presets are labelled Local only, Saved - slot N, or Changed - slot N. Envelope readback confirms which custom slots are occupied and verifies saves and deletions when supported by the firmware.

Play loops a browser preview of the envelope. Stop stops the browser preview only. It does not send a stop command to the hardware. Bounce is the reset preset because it shows the envelope shape clearly.

Mobile Web MIDI Notes

• Mobile browser support is less consistent than desktop support.
• If MIDI connects but no output appears, open Developer tools in the editor and check MIDI Ports Seen By Browser.
• Some mobile browsers report MIDI access but expose ports in a non-standard way. The editor tries several detection paths, but browser/device support can still vary.
• If ports still do not appear, reconnect the device, reload the page, and try another USB adapter, hub, or browser.

Build

cmake -S . -B build
cmake --build build

The built UF2 will be:

build/C1ZZL3.uf2

The production source build currently reports:

FLASH: 138160 B
RAM: 146500 B

Stability Notes

This build is close to the practical processing limit of this RP2040 card format, so future changes should be tested carefully at maximum settings.

The stable version includes the lookup-table oscillator optimisation, 192 MHz clock, Turing MIDI output, settings readback, and full CC/knob pickup handoff. Tap tempo remains removed; Y is the Turing internal clock control.

Possible future optimisation notes are kept in:

FUTURE_NOTES.md