The M-VAVE FM-1 is a ~$70 pocket FM synthesizer whose six-operator engine is, underneath, Dexed running on a JieLi SoC. Its updates travel over USB-MIDI SysEx with no cryptographic signature — just checksums. In six weeks the community turned that detail into a full alternative-firmware scene: grooveboxes, SP-1200-style samplers, a Prophet-5, kalimbas, and even Doom.
This is the catalog: every firmware we found, with its author, license, which classic synths it emulates, its status, and what it’s a fork of. Closed-source and paid ones are here too, labeled as such — the community hub only lists GPL; we list everything. Data as of October 9, 2026 — the scene ships releases daily, so treat this as a snapshot, not a mirror.
The same mechanism takes you back to the official V15 firmware whenever you want. The community’s golden rule: flash custom-over-custom only after returning to stock, and back up with each firmware’s editor before switching.
What if it bricks? It can — I documented it with my own corpse. Hold OCT− at power-on (USB rescue); the other two rescue ladders are in the ecosystem page.
Screenshots in each entry come from each project’s repository or site (GPL unless noted), with their source linked.
The FM-1's first custom firmware: patches the stock, fixes 4 factory bugs, adds a supersaw VA. Closed and free.
The base firmware: 13 engines, a deep sequencer, browser editor and emulator. Almost everything else forks this.
The free-take groovebox: record without a click, close the loop on the '1', zero factory patterns.
SLOOP with a DX7 inside: a Dexed engine verified sample by sample, and FM drums you program yourself.
A pocket SP-1200: 12 bits at 26 kHz, zero interpolation. The aliasing is the sound.
A 909, an 808, two 303s and breaks, all at once in stereo: a pocket ReBirth with TB-3PO.
The FM-1 as an Omnichord: strum plate, chord buttons, OM-84 rhythms with automatic bass.
Prophet-5 Rev 4, DX7 and Casio CZ-1 with real .syx, unquantized recording and 70 scales.
SLOOP stretched to 8 tracks: a looper per track, on-device slicer, chords named on screen.
Felucca with a dark-industrial-Brazilian aesthetic: breathing drones, a Moog ladder, the MANGUE maracatu kit.
Dungeon synth on your FM-1: hurdy-gurdy, bagpipes, chanting monks and a 12-second cathedral of reverb.
A pocket Orchid: roots in one hand, chords in the other, a semantic looper and three audio outputs.
The FM-1 as a physically modeled kalimba: six materials, gourd body, mbira buzzers, plate reverb.
An 8-track drum machine: modeled 808/909, Mutable Plaits/Grids/Streams, and a PERFORM mode.
![Screenshot of Felucca [Salt] running on the M-VAVE FM-1](/firmwares/felucca-salt/captura.jpg)
Browser Studio for Felucca 0.9: play the full synth without owning an FM-1.
Felucca 1.0.5.2 turned into a live rig with an Arturia MiniLab 3: 12-song setlist and autosave.
SLOOP with a visual 4-operator FM engine: the oscilloscope draws each operator's ADSR.
SLOOP 2.4 with up to 12 DX7 banks on board, managed from the web editor. Test builds.
The only paid firmware ($29 USD): a mod over stock V15, supersaw VA, and boots stock with OCT−+OCT+.
Playable Doom on the FM-1's screen, installed from the browser, and your sloopDX projects survive.
The other Doom: a Doomgeneric port whose current screenshots are desktop renders, unconfirmed on hardware.
The SLOOP core dressed up as an RPG: your tracks are heroes and your loops are boss fights.
A 'dark fractured lo-fi' groovebox whose only public existence is an installer on chatgpt.site.
The most ambitious project in the scene — and it has never written a single byte to a real FM-1.
Not a firmware: a factory. Compile your own, picking engines and FX to your flash budget.
Late-90s-style chop sampler — it won't be flashed until recovery is proven.
Experimental SLOOP fork with 16 engines piled on — Karplus-Strong included — nothing verified on hardware.
Polyphonic sequencer in strict C99, no malloc — the no-Felucca route. Dormant since day 2.
Felucca 1.0.2 piloted from an NI Kontrol S49 MK3. No release: compile it yourself.
The minimal mod: four bytes patched onto stock V15 — and in the public domain.