Les

FM-1 firmware · v1.1.1

fm1-sidj

A Commodore 64 music deck that plays the High Voltage SID Collection and lets you remix every voice live from the panel.

Made by
thomasj
Released
October 30, 2026
Install
On GitHub
Scan
Scanned, nothing harmful found · Oct 31 What we checked
Last checked
October 31, 2026

What fm1-sidj does

  • SiDJ turns the FM-1 into a player and live remixer for Commodore 64 music on a cycle-exact emulated C64.
  • It plays tunes from the High Voltage SID Collection through an emulated 6581 or 8580 chip, chosen per song.
  • Every one of the three voices can be transposed, muted, soloed, given a new waveform, sync or ring modulation.
  • The keys and a MIDI keyboard play a voice directly, either holding a note or shifting the tune's melody.
  • Knob pages cover pulse width, tuning, envelopes, cutoff and resonance, a per-voice LFO, tempo and a vinyl fader.
  • Everything you change turns gold on screen, and OCT- with OCT+ puts the whole tune back as written.
  • SAVE keeps your chip, output and USB audio choices along with the song that loads at power-on.
  • Sound reaches the audio jack, a computer over driverless USB audio as mix or separate voice stems, and real SID hardware over ASID.

Its modes

SONGS
Browse the tunes stored on the FM-1, grouped by composer, and pick the chip, output and USB audio layout before playing.
PLAYER
Watch each voice's scope, note, waveform, envelope and pulse width while the tune plays, and remix it live.
FX (OSC)
Turn the knobs for the selected voice's pulse width, octave and fine tune.
ENV
Shape the selected voice's attack, decay, sustain and release.
SEL (FLT)
Set the filter cutoff and resonance.
LFO
Set the voice's LFO rate, depth, target and shape.
GLO
Ride the tempo from 25 to 150 per cent and the vinyl fader.

What Les checked

fm1-sidj v1.2.0Scanned October 31, 2026

What we checked for

  • The file is exactly the one its author published
  • It opens cleanly as an FM-1 firmware, nothing damaged
  • It doesn't show up on your computer as a keyboard, mouse or other input device
  • It doesn't show up as a USB drive or network adapter
  • Its text mentions no computer command tools, like PowerShell, Terminal or a download command

What we found

  • MIDI and audio, as expected

StatusScanned, nothing harmful found

Les scans every firmware here whose file is public, and shows what it checked and what it found. A scan lowers the risk; it can't rule it out. This firmware is made by its author, not by Les or M-VAVE. Back up first, and install at your own risk. How Les scans firmware

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