# Melodee licensing Melodee is a modified version of Felucca by Leo Kuroshita (@kurogedelic), Hügelton Instruments (), and keeps Felucca's licensing. Melodee is free software, licensed under the GNU General Public License, version 3 only (`GPL-3.0-only`, full text in `LICENSE`). That covers the code and its own assets. A few bundled or ported parts keep their own licences; they are listed below, and their licence texts are in `LICENSES/`. Copyright (C) 2026 Leo Kuroshita (@kurogedelic), Hügelton Instruments\ Modifications Copyright (C) 2026 Kerem Kilic (Ellic Studio) ## What is GPL-3.0-only Every file in this tree that carries an `SPDX-License-Identifier: GPL-3.0-only` header: - the firmware: `firmware/` (app, HAL, update loader) - the build script and tools: `build.sh`, `tools/` - the web pages (installer, editor) and their tests: `web/` (not the Fukiai font, below) - the host tests: `tests/` Three source files are ports and keep the licence of their originals: `firmware/src/phys_dsp.c` (DaisySP, MIT), `firmware/src/phys_symp.c` (Rings, MIT), and `firmware/src/cz_native.c` (MAME uPD933, BSD-3-Clause). `firmware/src/fm6_core.c` and `firmware/src/eng_fm6.c` restate MSFA (Apache-2.0) and Dexed (GPL-3.0-or-later) in fixed-point C (below). The firmware built with them is GPL-3.0-only as a whole. You may use, study, change and share Melodee under the GPL. If you distribute Melodee, or firmware derived from it, you must also give your recipients its complete corresponding source under the same licence. That includes devices that ship with modified Melodee inside. ## Hügelton Instruments' own work All by Hügelton Instruments (Leo Kuroshita), in this tree: | What | Licence | Where | | --- | --- | --- | | Felucca: firmware, tools, web pages, tests | GPL-3.0-only | `LICENSE` | | The PHASE engine's waveforms: a C port of the oscillator of CrispyZebra () | GPL-3.0 | `firmware/src/eng_phase.c` | | The synthesized 808 drum kit (TR-808 circuit models) | GPL-3.0-only | `firmware/src/drum_808.c`, `firmware/src/eng_drum.c` | | The panel picture | GPL-3.0-only | `docs/panel.jpg` | | The Fukiai icon font (): the firmware's icons (rasterised at build time by `tools/gen_aa_icons.py`) and the web editor's | MIT | `web/fukiai.ttf`, `LICENSES/MIT-Fukiai.txt`, `web/FUKIAI-LICENSE.txt` | ## Third-party material | What | Licence | Where | | --- | --- | --- | | Inter Tight font by The Inter Project Authors: the UI text, rasterised into the firmware at build time (`tools/gen_aa_font.py`; the generated tables are not offered as a font, and the font declares no Reserved Font Name) | SIL OFL 1.1 | `assets/fonts/InterTight[wght].ttf`, `LICENSES/OFL-InterTight.txt` (also `assets/fonts/OFL.txt`) | | DaisySP by Electrosmith, Corp and Emilie Gillet (): the PHYS engine's modal and string models and the resonator, ported to fixed point | MIT | `firmware/src/phys_dsp.c`, `LICENSES/MIT-DaisySP.txt` | | Rings by Emilie Gillet (): the PHYS engine's sympathetic strings, ported to fixed point | MIT | `firmware/src/phys_symp.c`, `LICENSES/MIT-Rings.txt` | | MSFA (Music Synthesizer for Android, Copyright 2012 Google Inc.) and Dexed (Copyright 2013-2025 Pascal Gauthier, ; portamento rates by Jean Pierre Cimalando): the FM6 engine restates their synthesis in fixed-point C so that it renders the samples Dexed renders (MSFA's envelopes, pitch envelope, LFO, operator kernels and Dx7Note, Apache-2.0; Dexed's MARK I and OPL engines and its voice handling, GPL-3.0-or-later); their DX7 measurement tables and the tables Dexed computes at start (sine, 2^x, frequency, log-sine / exponent, OPL ROM, detune, LFO, portamento) are used as data. `tests/dexed_ref.cc` builds Dexed's own sources (from a checkout, not in this tree) to compare against. The FM6 factory patches are Felucca's own (F1..F8) and Melodee's own (F9..F24) | Apache-2.0, GPL-3.0-or-later | `firmware/src/fm6_core.c`, `firmware/src/eng_fm6.c`, `tools/gen_tables.py`, `tests/dexed_ref.cc`, `LICENSES/Apache-2.0-msfa.txt` | | MAME uPD933 device model by Devin Acker: native CZ phase functions, envelope rate law and logarithmic amplitude adapted to fixed-point C | BSD-3-Clause | `firmware/src/cz_native.c`, `LICENSES/BSD-3-Clause-uPD933.txt` | | Casio CZ-1 preset tones A-1..H-8 (Casio Computer Co., Ltd., 1986): the 64 factory sounds as native tone data, combined from the "64 original CZ-1 patches" SysEx (GeoCities CZ-101 page, archived 2009) and Oli Larkin's VirtualCZ conversions of the same presets (LCD names, line levels, velocity). Included as sound data for CZ-1 compatibility; the rights stay with Casio. See `assets/cz1-factory/README.md` | Casio's (no licence granted) | `assets/cz1-factory/cz1-factory.syx`, `tools/make_cz1_factory.py`, `tools/gen_cz1_factory.py` | | Sequential Prophet-5/10 factory programs v1.03 (Sequential, 2025; ): the 200 programs of `P5_Factory_Programs_USER_v1.03.syx`, unchanged native data, as PROPHET's factory presets and its default native user collection. Included as sound data for Prophet-5 compatibility; the rights stay with Sequential. See `assets/prophet5-factory/README.md` | Sequential's (no licence granted) | `assets/prophet5-factory/prophet5-v1.03.syx`, `tools/gen_prophet_factory.py` | | klattsch by Tony Gies (): design reference for the VOICE engine; no code copied. Formant data from Klatt (1980) / Hillenbrand et al. (1995) | MIT (klattsch) | credit only | | JieLi AC79 SDK by JieLi Technology: three of its files go into every `.fwsc` package (below); none are in this tree | Apache-2.0 | `LICENSES/Apache-2.0.txt` | On the device, HOME held > ABOUT opens the information screen; turning PRESETS scrolls on into CREDITS, a short list of these authors, licences and source URLs. ## JieLi SDK files in the packages (Apache-2.0) A `.fwsc` package made by `tools/build.py` (with `tools/fm1pkg_make.py`; this is the package the web installer installs) holds three unmodified files from the JieLi AC79 SDK (, `cpu/wl82/tools/`). They are read from your SDK checkout at build time (see BUILDING.md); no SDK files are in this tree. | File in the package | What it is | | --- | --- | | `uboot.boot` | the first-stage boot loader (SPL) | | `cfg_tool.bin` | the chip configuration block | | `eq_cfg_hw.bin` | the default hardware EQ table | They are licensed under the Apache License, Version 2.0 (`LICENSES/Apache-2.0.txt`), not under the GPL, and their copyright stays with JieLi Technology. The SDK has no NOTICE file. Apache-2.0 files may be distributed together with GPL-3.0 code; Melodee itself stays GPL-3.0-only. Every distribution of a package carries the licence texts with it: the release folder (`tools/build.py --release`) and the site (`web/make_site.py`, next to the package in `firmware/` and linked from the installer page). ## No vendor material No M-VAVE material is part of Melodee. The firmware links no vendor code and contains no vendor data, and the packages hold only Melodee and the three SDK files above. The installer's "Return to official V15" holds only the official file's size and SHA-256: you select the official firmware file you downloaded yourself, and it is checked and installed in your browser, never uploaded or redistributed. ## Contributions Contributions are welcome under GPL-3.0-only. ## Trademarks "Felucca" and "Hügelton Instruments" are names of Hügelton Instruments. "M-VAVE" and "FM-1" are trademarks of their respective owners. Melodee is independent firmware that runs on FM-1 hardware. It is not affiliated with, endorsed by or supported by those owners, nor by Hügelton Instruments. ## Radio Melodee never enables the Bluetooth / Wi-Fi radio of the hardware. ## The installer's m-bootloader step `web/m-bootloader/fm1-uboot-1.2.fwsc` is m-bootloader 1.2 by Julius Vitkauskas (MIT, `web/m-bootloader/LICENSE`), from github.com/jvitkauskas/m-bootloader. The site publishes it next to the firmware with its licence (`firmware/m-bootloader-LICENSE.txt`). The installer's m-bootloader step, its check for M-VAVE's Open firmware and its port names in `web/fm1ota.js` follow fm1-base's installer by Charles Vestal (MPL-2.0, github.com/charlesvestal/fm1-base), which credits Chris Farrell's fm-static for the Open firmware's identities. MPL-2.0 lets that code sit in this GPL-3.0 project (MPL-2.0, section 3.3).