Crepuscular Homunculus
A dark, standalone synth and four-track groovebox for the M-VAVE FM-1.
Created by TERKINSTEIN · Free and open source
Turn your FM-1 into an instrument for atmospheric pads, heavy bass, metallic textures, synthesized drums and six-operator FM. Play, build patterns and save complete songs on the FM-1 itself.
Download 0.26.19 · Try the virtual FM-1 · Visit terkinstein.com
Learn with the illustrated tutorial — follow each button press, hold and resulting screen.
What you can do
- Explore 64 factory sounds, then shape them with the FM-1's controls.
- Build a song on four tracks: DRUM, MELODY, ATMOS and BASS, each with its own captured sound.
- Create variations with four A–D banks per track and up to 64 steps per bank.
- Edit notes directly with step entry, live recording and the native piano roll.
- Add swing, use the arpeggiator, or play from a MIDI keyboard with pedal support.
- Choose your HOME display: the reactive Homunculus or Thorn Rift, following the creator startup logo.
Get started
- Download the
.fwscfirmware from the 0.26.19 release. - Protect your music. Stop playback, release keys and pedals, press SAVE and wait for SAVED. Keep a separate backup and your previous firmware.
- Install from a computer using the installation guide.
- Start playing with the illustrated tutorial, or use the shorter quick start.
The release also includes matching source code, checksums and licensing information. After installation, the instrument works without a computer.
Find the right guide
| I want to… | Read this |
|---|---|
| Follow button presses and holds with screen pictures | Illustrated tutorial |
| Play a sound and make a pattern | Quick start |
| Learn the buttons and knobs | Panel controls |
| Edit individual notes and chords | Piano roll |
| Explore the sound collection | Sound guide |
| Install, switch back or recover | Installation and recovery |
| Understand older-song compatibility | Saved songs and sound revisions |
| See what changed in this release | Release notes |
A few useful limits
Eight voices are shared across the four tracks, LIVE playing and release tails; at most four voices can use FM. Large chords and overlapping tails share that budget. The FX button bypasses corrosion/BITE rather than every sound control.
Supported older Homunculus songs migrate explicitly. Projects, sounds and samples from unrelated firmware are not imported automatically. See performance limits and validation for the details.
Source and credits
This repository contains only Crepuscular Homunculus firmware, artwork, platform and update code, build tools, tests and documentation for this instrument.
Developers can start with the build guide and architecture. The complete source for this release is at tag v0.26.19.
Licensed under GPL-3.0-only. Derived from Dinghy, with Felucca/SLOOP platform work; see licensing and credits. M-VAVE and FM-1 are trademarks of their owners. This is an independent project.
The HOME picture is a native host render, not a hardware photograph.