FM-1 SID
Turns the FM-1 into a Commodore 64 SID synth with twelve instruments, a three-track step sequencer and stereo effects, and also plays C64 tunes by running their own 6502 code.
Brick risk. Flashing this carries a known, documented risk of damaging the device.
- Distribution
- Prebuilt image you flash yourself
- License notes
- The player firmware and effects are GPL-3.0-only because they build on Felucca's HAL and effects code, and they link reSID 0.16, which is GPL-2.0-or-later. The author's own SID model and synth driver are BSD-2-Clause. It also ships three Apache-2.0 files from JieLi's AC79 SDK. The rest of the fm1-emu repository is MIT.
- Source
- github.com https://github.com/joakimeriksson/fm1-emu/tree/master/fm1-sid
- Homepage
- joakimeriksson.github.io https://joakimeriksson.github.io/fm1-emu/fm1-sid/
- synth-engine
- sequencer
- fx
- emulator
- research
Description
Built on Felucca's hardware layer, with the SID chip rendered by reSID 0.16 or by the author's own integer model and a driver that plays it the way C64 music does. In synth mode the note keys play twelve instruments, the knobs set cutoff, resonance, attack and release, and a three-track, 16-step sequencer and a chorus, delay and reverb sit on top. In player mode it runs PSID tunes on an emulated 6502 and draws the voices, sync, ring modulation and filter on the screen; RSID tunes are not supported. Tunes are appended after the firmware image as a pack. The same code runs as a web page that plays tunes from the HVSC archive, and the FM-1 emulator entry names it as one of the firmwares it runs. The README says it has run in the emulator only and has not been tried on a real FM-1.
Install notes
The repository carries a ready-made update package, fm1-sid/web/sidplayer.fwsc, and build scripts that need JieLi's Linux toolchain and fetch their GPL dependencies on demand. The README gives no install procedure for a real unit and says it has not been run on one. It uses Felucca's update loader. Hold OCT- and OCT+ for three seconds to enter its USB update mode.
Version history
| Version | Date | Notes |
|---|---|---|
| master @ 687ce7d | 2026-10-13 | No tagged releases; this is the latest commit touching fm1-sid/. The emulator's firmware list labels the package 0.1. |