Les

FM-1 firmware · v0.4.0-rc1

bongo-cat-studio

A little band of four cats: you play and loop the melody while keys, bass and drum cats follow your chords.

Made by
Impossible Knot
Released
October 23, 2026
Install
On GitHub
Scan
Scanned, nothing harmful found · Oct 31 What we checked
Last checked
October 31, 2026

What bongo-cat-studio does

  • Four parts, your cat plus keys, bass and drums, can each use any of thirteen synthesis engines.
  • Engines cover analog, phase, lo-fi, samples, voice, trio, wheel, granular, physical modelling, drums, noise, FM6 and slice.
  • Press REC while stopped for a one-bar visual lead-in, then record a 1, 2 or 4 bar phrase.
  • OVERDUB adds notes at the next phrase start, REPLACE clears the old take, and LFO undoes one step.
  • The panel keyboard plays the selected cat, with key assist snapping notes into your chosen major or minor key.
  • Harmony keeps the band in key with HOLD, COZY, DREAM and JAZZ progressions, one chord per bar.
  • LIVE gives each cat a PLAY, MUTE and SOLO knob, with ENV as tap tempo that yields to external MIDI clock.
  • SAVE and the CRC-checked autosave keep the phrase, sounds, mixer, harmony, tempo, coat, hat and room for next boot.

Its modes

Studio
Set tempo, swing, band energy and room reverb while the band plays.
Harmony
Choose the key, major or minor, the chord progression and key assist.
Looper
Set phrase length of 1, 2 or 4 bars, replace or overdub, timing feel and the metronome.
Mixer
Balance the levels of your cat, keys, bass and drums.
Dress up
Pick the coat, hat, room colour and calm or lively animation.
Help
Switch the metronome between off, record and on with knob 1.
Sounds
Choose the part, its engine, its factory preset and its level.
Tone / Colour
Adjust the eight engine controls, whose labels follow the chosen sound.
Envelope
Shape the selected part's attack, decay, sustain and release.
Effects
Set drive, chorus, delay and reverb for the selected part.

What Les checked

bongo-cat-studio v0.4.0-rc1Scanned October 31, 2026

What we checked for

  • The file is exactly the one its author published
  • It's the same file we saw when this release first came out
  • 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
  • A serial port, which many FM-1 firmwares keep for debugging. It can't type into your computer.

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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