An alternative firmware for the M-VAVE FM-1, for electroacoustic experimentation, live ambient music and sound exploration.

Install via browser · Manual · Website · Changelog

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Warning

Installing Tonitor replaces the firmware M-VAVE ships with the FM-1. It is unofficial, is not made, endorsed or supported by M-VAVE, and installing it may void any warranty that applies to your device. You install it at your own risk; read the disclaimer first.

What it is

Tonitor turns the FM-1, a small FM groovebox, into an instrument for acousmatic and electroacoustic music — sound heard for itself, its texture, its grain and its movement — and for live ambient music, dark ambient above all.

It is not a groovebox. There is no tempo, no step sequencer, no pattern, no drum kit. Instead there are six tracks of sound objects: each track has its own engine, its own sound, voices drawn from a shared pool as it needs them, and its own free loop recorder, and every sound is drawn by algorithms that aim for surprise rather than for a preset that sounds nice. You play textures, drones, gestures and their slow transformations, layer them, loop them freely out of time with each other, and shape them while they play.

The screen is made for low vision: very few words, in very large type, with high contrast, and each track in its own colour.

Highlights

• Eight sound engines, chosen per track:
  • FM — six-operator, DX7-style FM, generating sound objects: bells and gongs, spectral drones, noise, impacts, iterations, glissandi, beating spectra, sub-bass, creaks.
  • ANIMA — a lo-fi synthesizer played by a simulated hand (oscillators, FM, grains, noise, filters, folding, a phaser and a resonator), all moved by the hand's gestures.
  • CALIGULA — a restless eight-oscillator organism after the architecture of the LYRA-8, with cross-modulation, a hyper-LFO, bursts and surges, and a simulated hand on its plates.
  • RUSSOLO — noise, logic and broken buffers: sample-and-hold and dusty noise, oscillators combined bit by bit, generated buffers read with their address bits bent, chance-driven tones; crushed and sample-held like a small DAC.
  • DRUID — strings and resonant bodies after Mutable Instruments Rings: a Karplus-Strong string with dispersion, sympathetic strings, and a modal resonator, plucked, struck, bowed or rattled.
  • BAYAREA — a West Coast voice: a morphing oscillator with two FM modulators, a wavefolder, and a low-pass gate or a sustaining envelope over resonant low-passes.
  • HIVE — a swarm of seven oscillators per voice, detuned, stacked or on inharmonic partials, moved by slow LFOs and noise, through a 4-pole filter with its own envelope and a drive; melodic kinds and textural ones.
  • OBRADOR — an analog polysynth after the Oberheim SEM: two oscillators and a second voice card, the SEM's filter morphing from low-pass through notch to high-pass, analog envelopes and drift.
• Generative paths — lean each track's new sounds towards AMBIENT (ethereal, melodic, dark) or EXPERIMENTAL (edgier, gnarlier, more textured), or leave it OPEN.
• Performance effects: hold a key and the filters, granulators, crush, distortion, sends, delay and reverb jump to values drawn at random, following each track's path; let go and they return.
• Play along: other tracks improvise with the one you play (REACT), shadow it (SHADOW) or arpeggiate its chords (ARPEGGIO).
• Six free loopers, one per track, with up to ten overdubs each, every loop with its own length.
• Envelope: attack, decay, sustain and release per track, on the ENVELOPE page, drawn on the screen.
• Latching: hold notes, press SHIFT, and they sustain as drones while you play on top.
• Per track: DJ resonant filter, granulator (dark ↔ scatter), bit/rate crush, distortion, level, pan and a send to a lush master reverb (Dattorro plate).
• Scales on the white keys (23: the seven modes, minors, pentatonics, blues, whole tone, octatonic, Hungarian minor, double harmonic, enigmatic, Prometheus, Japanese and Balinese scales), any root.
• 64 session slots in the FM-1's flash: every track, sound, loop and setting.

Installing

The easiest way is the browser installer: connect the FM-1 with a USB data cable, open the page in a desktop Chrome, Edge or Opera (they support Web MIDI with SysEx), and follow it. It finds the FM-1, checks what it runs, writes Tonitor and checks the result. Nothing is uploaded anywhere: the page talks to the FM-1 directly.

It installs over whatever the FM-1 runs now — M-VAVE's own firmware, another alternative firmware or an earlier Tonitor. It runs on FM-1 units with either flash chip: the P25Q80 of earlier units and the UC25HQ80 of units sold from autumn 2026 (from build 72; not yet tested on a unit with the UC25HQ80). Do not unplug the FM-1 while it writes.

To build and install from source instead, see Building from source.

If something goes wrong: hold OCT− while switching on for the USB rescue mode (the screen says RESCUE), then install again. Two failed starts in a row also enter it. Holding OCT− and OCT+ for five seconds enters the chip's own updater (UBOOT). If the FM-1 no longer starts at all, recovery needs FM-1-transporter.

Going back: the installer and ./install.sh install any FM-1 package; to return to M-VAVE's firmware, use M-VAVE's own updater. Apart from the update itself, Tonitor writes to the FM-1's flash only when you save a session — into a user data area that other firmwares may also use, so saving Tonitor sessions overwrites any projects another firmware left there.

Manual

Playing it

Control	What it does
FX SEL ENV LFO EDIT GLO (top row)	choose track 1–6 (lit: chosen; glowing: sounding). From any page, back to playing. Held (0.8 s): copy the track, or paste the copy onto it (Copying a track).
PRESETS knob	the chosen track's engine: FM, ANIMA, CALIGULA, RUSSOLO, DRUID, BAYAREA, HIVE, OBRADOR. Each track keeps one sound per engine. At start, and in an empty session, tracks 1–6 are on FM, ANIMA, CALIGULA, HIVE, DRUID and BAYAREA.
SHIFT + PRESETS	a new sound of the previous or next family.
HOME	a new sound for the chosen track.
SHIFT + HOME	a new sound of the same family.
OCT− / OCT+	the chosen track's octave, −3 to +3.
SHIFT + OCT− / OCT+	every loop of every track one step of the scale down or up (Loopers).
SHIFT + a track's button held + OCT− / OCT+	that track's loops only.
the white keys	play the chosen track in the scale; the first white key is the root, and the root's keys glow dimly. A held note keeps sounding when you choose another track. The tracks share twelve voices.
the rightmost black key	SHIFT. Hold white keys and press SHIFT to latch them; SHIFT + a lit key releases it (Latched keys).
black key 1	the chosen track's generative path: pressed, AMBIENT; held (0.6 s), EXPERIMENTAL; the same again: OPEN (Generative paths). Lit on AMBIENT, blinking on EXPERIMENTAL.
black key 2	held: the effects at random, until you let go (Performance effects).
SHIFT + black key 2	the PERF FX page.
SHIFT + black key 1	a new scale and root, drawn at random; the SCALE page shows them for 1.5 s (Scales).
black key 3	chord mode: held (0.6 s), on or off; pressed, the next chord form (Chords).
black keys 4, 5, 6	the chosen track's loops REVERSE, PENDULUM, RANDOM; pressed again, forwards (Direction and speed). Only while its loops play.
black keys 7, 8	the loops at HALF SPEED or DOUBLE SPEED; pressed again, normal speed. Only while the loops play.
black key 9 (3rd from the right)	the ENVELOPE page (Envelope). SHIFT +: BRICKLAYER on or off; held (0.6 s) while it is on: its page (BRICKLAYER).
black key 10 (left of SHIFT)	EDIT: KNOB 1–4 become four macros (Macros). SHIFT +: BALLSY on or off; held (0.6 s) while it is on: its page (BALLSY).
ARP	the SCALE page: SELECT sets the root, ALGORITHM the scale (Scales).
SHIFT + ARP	the engine's PRESETS page (Presets).
REC	press to arm; the first note starts the loop; REC again ends it and it plays. REC while it plays: overdub. Up to 10 loops a track.
SHIFT + REC	VARY on or off: the loops play with random changes of level, length, timing, notes and pace, always in the scale.
REC held (1 s)	empty the chosen track's loops.
PLAY	stop or restart the chosen track's loops. Held: bring loops in or out on the white keys. On BALLSY's or BRICKLAYER's page: start or stop that sequencer.
SHIFT + PLAY	stop everything, or, if nothing plays, start every loop and sequencer.
SELECT knob	the chosen track's level, OFF to +4.5 dB.
ALGORITHM knob	the chosen track's pan.
KNOB 1	the chosen track's filter: off in the middle, low-pass to the left, high-pass to the right.
KNOB 2	the chosen track's granulator: off in the middle, dark to the left, scattered to the right (Granulator).
KNOB 3	the chosen track's crush: off in the middle, fewer bits to the left, a lower sample rate to the right.
KNOB 4	the chosen track's reverb send.
SHIFT + KNOB 3	the chosen track's distortion (Distortion).
SHIFT + KNOB 4	the chosen track's delay send.
SAVE	the SNAPSHOTS page; SAVE again leaves it (Snapshots).
SAVE held (0.8 s)	save the session. With none loaded, it offers the first empty slot; on the SESSIONS page, it saves into the slot shown and asks before overwriting; on the SNAPSHOTS page, it stores the current state in the framed snapshot.
SHIFT + SAVE	the SESSIONS page: PRESETS chooses a slot, SAVE loads it; on an empty slot, SAVE starts a new, blank session there. SHIFT + SAVE again leaves it (Sessions).
SHIFT + SAVE held (0.8 s)	GLOBAL SETUP: the MIDI, AUDIO and SETTINGS settings (Global setup and MIDI).
SHIFT + black key 7 held	the CPU page while held: the load and the heaviest processes (CPU load).
SHIFT + black key 8	the screen reader on or off, from any page (Screen reader).
SEQ	the DELAY, REVERB, MOD and PLAY ALONG pages in turn, then back (Delay, Reverb, Modulation, Play along).
SHIFT + SEQ	a new random modulation for the chosen track.
MASTER	the output level.
MIDI in (USB and TRS)	notes and CCs for each track (Global setup and MIDI).

Generative paths

Each track has a path that steers the sounds HOME draws next on it; sounds already playing do not change. Every track starts on OPEN, and sessions keep each track's path.

Path	Key	Leans towards
AMBIENT	black key 1 pressed (lit)	ambient and dark ambient: soft attacks, long tails, darker, often melodic
EXPERIMENTAL	black key 1 held 0.6 s (blinking)	electroacoustic and acousmatic: noisier, brighter, more bent, crushed and driven
OPEN	the same again (dark)	every family alike

Macros

Press EDIT (black key 10) and KNOB 1–4 become four macros that reshape the chosen track's sound. The middle is the sound as HOME drew it; turn either way. The screen shows the macro's name and position. Press EDIT again to get the knobs back. Each sound keeps its macros, and sessions and presets store them.

	KNOB 1	KNOB 2	KNOB 3	KNOB 4
FM	BRIGHTNESS	DETUNE (INHARMONIC on metallic and noisy families)	SATURATION	MOTION
ANIMA	TONE	GRAINS, NOISE, FM, FORMANT or DRIVE, by kind	RESONATOR	MOTION
CALIGULA	WAVEFORM	MOD DEPTH	FEEDBACK (DELAY on SPORE, VEIL, LITANY, MOTH)	TOUCHES (GATE RATE on HIVE, MOTH, WIRE)
DRUID	STRUCTURE	BRIGHTNESS	DAMPING	POSITION
BAYAREA	SHAPE	FOLDS	FM	DECAY
HIVE	DETUNE	MOVEMENT	MIX (NOISE on GROUND, AIR)	CUTOFF
OBRADOR	CUTOFF (four octaves either way)	MORPH (the filter: low-pass, notch, high-pass)	RESONANCE	DETUNE (none to three times as wide)
RUSSOLO	the kind's first parameter	the kind's second parameter	CRUSH	RANDOMNESS

Envelope

Black key 9 opens the ENVELOPE page with the chosen track's amplitude envelope (AS DRAWN until you change it). KNOB 1–4 set ATTACK (1 ms – 10 s), DECAY (5 ms – 10 s), SUSTAIN (0–100 %) and RELEASE (5 ms – 20 s). A change applies from the next note, and after that to the notes sounding too. HOME or loading a preset brings back the sound's own envelope. Sessions store the envelopes; presets do not.

PLAY, sequencers and looper

A track runs one sequencer at a time: with BALLSY on, BRICKLAYER shows NOT ALLOWED, and the other way round. A sequencer waits for PLAY on its own page. On every other page PLAY is the looper's, so you can record loops over a running sequencer. The looper records only the keys, never the sequencer.

BALLSY

SHIFT + EDIT turns on BALLSY, a sequencer of bouncing balls, for the chosen track and shows its page (EDIT blinks while it is on). PLAY starts and pauses the balls. Hold EDIT (0.6 s) to hide or show the page; the balls keep playing.

Each time a ball hits a wall it plays a note in the scale, of random length and level, with chord mode and the loops' transposition. The pitch rises clockwise, one octave per wall:

Wall	Octave (at the start)	Pitch rises
bottom	−1	right to left
left	0	upwards
top	+1	left to right
right	+2	downwards

Knob
KNOB 1	the number of balls, 1–8
KNOB 2	speed
KNOB 3	the walls' octaves, moved together
KNOB 4	instability: the balls speed up, slow down and turn at random; at 0, steady and straight

BRICKLAYER

SHIFT + black key 9 turns on BRICKLAYER, a step sequencer built a note at a time, for the chosen track and shows its page (the key blinks while it is on). PLAY starts and stops it. Hold black key 9 (0.6 s) to hide or show the page; it keeps playing.

On its page, REC is the entry, not the looper:

Gesture
REC	entry on or off
a white key, entry on	add its note at the end
SHIFT + a white key, entry on	take that note out
SHIFT + REC	take the last note out
REC held 1 s	empty the sequence

The notes are spread evenly over the length (3 notes in 8 steps fall on steps 1, 4 and 7) and follow the scale, the root, the loops' transposition and chord mode.

Knob
KNOB 1	LENGTH: from the number of notes up to 32 steps
KNOB 2	RATE: 0.5–16 steps a second
KNOB 3	HARMONY: how often a note becomes a two- or three-note chord
KNOB 4	VARIATION: random level, length and pace, stutters, repeats, echoes and ghost notes; at 0, steady

On its page, black keys 4–8 set BRICKLAYER's own direction and speed.

Latched keys

Hold white keys and press SHIFT: they latch and stay lit. SHIFT + a lit key releases it. Latches belong to the track they were made on; on another track the same keys play as usual, so a drone can sound on one track while you play another. Loading a session releases every latch.

Chords

With chord mode on (black key 3 held 0.6 s; CHO on the screen), each white key plays three notes of the scale. Press black key 3 to step through the forms (in steps of the scale from the key's note):

Form	Steps
TRIAD	0, 2, 4	root, third, fifth
INV 1	2, 4, 7	first inversion
INV 2	−3, 0, 2	second inversion
SUS2	0, 1, 4	the second instead of the third
SUS4	0, 3, 4	the fourth instead of the third
OPEN	0, 4, 9	root, fifth, the third an octave up
FOURTHS	0, 3, 6	stacked fourths

One chord sounds at a time on a track. Chords latch, loop and are saved like single notes.

Direction and speed

Black keys 4–8 set how the chosen track's loops play. They work only while that track has loops and they are playing (PLAY lit): then they glow dimly, and the setting in use is lit. With no loops, or the loops stopped, they are dark and do nothing. They have no effect on the sound itself:

Key	Setting
black key 4	REVERSE: backwards
black key 5	PENDULUM: forwards, then backwards, in turn
black key 6	RANDOM: at each note, a jump to a note of the loop drawn at random
black key 7	HALF SPEED (the pitch does not change; held with SHIFT: the CPU page)
black key 8	DOUBLE SPEED (with SHIFT: the screen reader on or off)

The three direction keys exclude each other, as do the two speed keys; a direction and a speed combine. Press the lit key again to go back to forwards or normal speed. Emptying the loops (REC held) resets both.

Copying a track

Hold a track's button until the screen shows COPIED / TRACK n (the button blinks). Choose another track and hold its button until PASTED / TRACK n. The track pasted onto gets everything of the copied one, its sounds, settings and loops, except its own level and pan; its latched notes are released.

Loopers

Each track has a looper of up to ten loops, and they run free: no tempo, no grid. Each overdub is as long as you played it, so the loops drift against each other. A note held from the loop's first moment to its last (still down when REC ends it) is tied over its end: while it still sounds (a drone, a pad) it goes on, one unbroken note; once it has died away (a pluck, a bell) it is struck again at the start of each round. Other notes still held when REC ends the loop are let go at its end, their release ringing on into the next round. Loops share the twelve voices with the keys and the other tracks.

Bringing loops in and out. Hold PLAY: the chosen track's loops appear on the white keys, the first loop on the leftmost, lit while they play. Press a key to take its loop out, or to bring it back in from its start. With the loops stopped, this chooses which loops the next PLAY starts.

Where each loop begins. Each loop keeps the moment its first note was played, counted from the first loop's start, and keeps its own length. Where every loop is follows from those two, so the loops always stand against each other as they did when you played them, round after round. When PLAY starts the loops again, they go on from the start of the first loop's round in which the newest loop was recorded: the first loop from its start, the newest silent until the place of its first note, and every other loop where it was at that moment. A loop brought back in (PLAY held) comes in where it would be had it played on. A loop recorded with the loops stopped begins with the first. Sessions and snapshots keep where each loop began.

Moving the loops along the scale. SHIFT + OCT+ / OCT− moves every loop of every track one step of the scale (TRANSP +1), up to two octaves either way; the white keys and latched notes move with them, and an overdub recorded meanwhile plays back as you played it. SHIFT + a track's button held + OCT+ / OCT− moves that track's loops only (TRANSP T3 +2). Emptying a track's loops resets its own move.

Screen

From the top: the track number in the track's colour, with the octave, VAR (while the loops VARY) and the battery at the top right; the engine; the sound's family, or a short message; ARMED or REC while the looper records; the track's level meter, with a mark at its SELECT level; and its pan. KNOB 1–4 show a full-screen dial while they turn.

Track colours: 1 yellow, 2 cyan, 3 pink, 4 green, 5 orange, 6 lilac.

Scales

One scale and root for all the tracks, saved with the session. At start, and in an empty session, both are drawn at random (ARP shows which); SHIFT + black key 1 draws them again, and the loops follow the new scale. The root is the first white key (C3 to B3, moved by each track's OCT), and the scale climbs across the 16 white keys.

Scale	Steps
MAJOR	0 2 4 5 7 9 11
MINOR NATURAL	0 2 3 5 7 8 10
MINOR HARMONIC	0 2 3 5 7 8 11
MINOR MELODIC	0 2 3 5 7 9 11
DORIAN	0 2 3 5 7 9 10
MINOR PENTA	0 3 5 7 10
WHOLE TONE	0 2 4 6 8 10
ENIGMATIC	0 1 4 6 8 10 11
JAPANESE IN	0 1 5 7 8
PHRYGIAN	0 1 3 5 7 8 10
LYDIAN	0 2 4 6 7 9 11
MIXOLYDIAN	0 2 4 5 7 9 10
LOCRIAN	0 1 3 5 6 8 10
MAJOR PENTA	0 2 4 7 9
BLUES	0 3 5 6 7 10
HUNGARIAN MINOR	0 2 3 6 7 8 11
DOUBLE HARMONIC	0 1 4 5 7 8 11
PHRYGIAN DOMINANT	0 1 4 5 7 8 10
JAPANESE HIRAJOSHI	0 2 3 7 8
JAPANESE IWATO	0 1 5 6 10
PELOG	0 1 3 7 8
OCTATONIC	0 1 3 4 6 7 9 10
PROMETHEUS	0 2 4 6 9 10

MIDI notes are not quantised to the scale.

Global setup and MIDI

SHIFT + SAVE held (0.8 s) opens GLOBAL SETUP, the FM-1's own settings (MIDI, AUDIO and SETTINGS), kept apart from the sessions. PRESETS moves through the entries; SAVE opens one, or selects a value and sets it; SHIFT + SAVE cancels or goes back a level. A track button leaves; changes are kept.

AUDIO has one setting, USB: what the FM-1 sends to a computer as USB audio (USB audio). STEREO (at the start): the master, as the headphones hear it. TRACKS: the six tracks, each on its own mono channel. Changed, the FM-1 leaves the USB for a moment and comes back as the new device; the sound on the headphones goes on.

SETTINGS has two: SCREEN READER (ON / OFF, OFF at the start) and SPEECH RATE (1 to 5, 2 at the start) (Screen reader).

MIDI's parts:

Part	Settings	At the start
IN CHAN	TRACK 1 to 6: the channel each track listens to (OFF, 1–16); AUTO: the channel that plays the chosen track	1 to 6; AUTO 16
OUT CHAN	TRACK 1 to 6: the channel each track sends on (OFF, 1–16)	1 to 6
RECEIVE	NOTES, CC (ON / OFF)	ON, ON
SEND	NOTES, CC (ON / OFF)	OFF, OFF
PORTS	USB IN, TRS IN (the 3.5 mm MIDI IN jack, Type A)	ON, ON

A note plays every track whose IN channel it arrives on (and the chosen track on AUTO). Each track answers to, and with SEND CC on sends, these CCs on its channel:

CC		CC
7	level	74	filter (64 off; below, low-pass; above, high-pass)
10	pan	91	reverb send
16–19	the four macros	92	delay send

With SEND NOTES on, each track sends the notes it plays (keys, loops, sequencers, MIDI) on its OUT channel over USB. There is no MIDI clock, transport or program change.

Screen reader

The FM-1 can speak what its screen shows, for players who cannot see it. The voice is made on the FM-1 itself and comes out of its own output, so no computer or internet connection is needed.

SHIFT + black key 8 (the 4th black key from the right) turns it on or off from any page; the key is not lit. It says "screen reader on" and reads the screen, or "screen reader off" and goes quiet. The same setting is in GLOBAL SETUP > SETTINGS > SCREEN READER. It is off at the start, and is kept, like the other GLOBAL SETUP settings.

When something on the screen changes, it is read once the screen settles (while a knob turns, at least every 0.7 s): the track number, its engine and sound; a knob's parameter and value; messages. On a list, it reads the page's title and the chosen row. Abbreviations are said in full (CHO: "chord"); acronyms (FM, LFO, USB) and words it does not know are spelled out; numbers are read with their signs and units ("−28.5DB": "minus twenty eight point five decibels").

The music drops 6 dB while it speaks. The voice follows MASTER and is not sent over USB audio. SPEECH RATE (GLOBAL SETUP > SETTINGS) sets its speed, 1 (slowest) to 5 (fastest), 2 at the start; while you set it, the reader already speaks at the new rate. When the reader is off, the audio does no work for it beyond one check.

CPU load

How much the FM-1 can play at once depends on the engines and effects in use: ANIMA, HIVE, DRUID and CALIGULA cost more than FM, and the effects add to it. Hold SHIFT + black key 7 (the 5th black key from the right) to see the CPU page for as long as the key is held.

• CPU and a percentage: the audio load now, the time the FM-1 takes to make each piece of sound against the time it has. Green below 60 %, yellow below 85 %, red above.
• The bar: the load, with a white mark at the highest load of the last 2 seconds (PEAK) and a red mark at 85 %. Above it, the FM-1 lets the quietest tails go, and then notes, to keep the sound going without gaps.
• HEAVIEST: the four processes using the most, the heaviest first, each as a share of one core's time: a track's engine (T3 CALIGULA: its voices together), a track's effects (T1 EFFECTS: its envelope, filter, granulator, crush, distortion and sends) or the master DELAY REVERB. The voices are spread over the FM-1's two cores, so the shares can add up to more than the load.

When the load nears the red mark, the top of the list shows what to change: fewer notes on that track, a lighter engine, or less of its effects.

Modulation

Each track has two LFOs and four modulation slots. Press SEQ three times for the MOD page: PRESETS chooses the entry, KNOB 1–4 set its rows.

Entry	KNOB 1	KNOB 2	KNOB 3	KNOB 4
LFO 1, LFO 2	SHAPE: SINE, TRI, SAW UP, SAW DN, SQUARE, STEPS, DRIFT	RATE: 0.01–20 Hz	MODE: FREE, NOTE (restarts at each note), ONCE (one cycle from each note)	FADE: in over up to 10 s
MOD A – MOD D	FROM: OFF, LFO 1, LFO 2, VELOCITY, KEY, RANDOM	TO: the four macros, FILTER, GRAINS, CRUSH, DRIVE, REVERB, DELAY, LEVEL, PAN, LFO 1 RATE, LFO 2 RATE	AMOUNT: −100 to +100	NOW: what the slot does at the moment

SHIFT + SEQ draws a random modulation for the chosen track; press again for another. HOME also draws one with some sounds, mostly slow FM, HIVE, BAYAREA and DRUID sounds. Sessions keep each track's modulation.

Play along

Other tracks play along with the one you play. The chosen track is the guide. The tracks you take in listen to everything the guide sounds (its keys, latches, chords, MIDI in, loops, BALLSY and BRICKLAYER) and play their own sounds in answer, in the scale. Three modes: REACT, SHADOW and ARPEGGIO. After the SMK-37 Pro port of Tonitor.

To turn it on:

1. Press the track button of the track you will play: it becomes the guide.
2. Press SEQ four times: the PLAY ALONG page.
3. Turn PRESETS to choose the mode: REACT, SHADOW or ARPEGGIO.
4. Press the track buttons of the tracks that should play along (2 IN, 3 IN ...). At first no track is in, and with none in, nothing plays along.
5. Press PLAY: the mode is on, its name in its colour (grey while off).
6. Press SEQ to go back to playing, and play the guide.

To turn it off, open the page again and press PLAY (REACT OFF ...). While it is on, PLAY flashes with each note the guide plays, and SEQ blinks slowly off the page.

On the page:

• PRESETS: the mode. Changing it lets go of the notes the tracks are playing.
• PLAY: the mode on or off.
• The track buttons: tracks in or out (2 IN, 2 OUT). The guide's button stays lit; a track taken in glows dimly; a track out is dark. The guide's own button says GUIDE TRACK (a track cannot follow itself).
• KNOB 1–4: the mode's values, 0–100; ARPEGGIO has two more, on SELECT and ALGORITHM. In REACT and SHADOW, SELECT and ALGORITHM stay the guide's level and pan. The page shows the knob turned last, its value large, and a bar for each.
• SEQ: back to playing; the mode goes on running. Choosing another track there makes it the guide.

The tracks taken in play their notes as a sequencer's: the looper does not record them, and they never play on the guide. When the guide stops, they stop. Sessions and snapshots keep PLAY ALONG: on or off, the mode, the tracks taken in and the values.

REACT improvises from a memory of everything the guide plays: its last 128 events (notes or chords), with their levels, lengths and the gaps before them. Each track taken in goes on as the guide once went on, or jumps to another place where the guide played the same intervals, so its lines are the guide's own, recombined, in the guide's rhythm. Its notes fit the harmony the guide holds. At each of the guide's phrases the tracks regroup, each taking a way to play: FOLLOWS (with the guide), CONTRASTS (slow under a busy guide, moving under long chords), ECHOES (the guide's line a few events behind, a third, sixth or octave away), ANSWERS (in the guide's rests), or RESTS. After François Pachet's Continuator, IRCAM's OMax and Somax, and George Lewis's Voyager.

Knob
KNOB 1	DENSITY	how much they play, how long they wait, how many sit out
KNOB 2	COMPLEXITY	low: single notes in plain rhythms; high: harmonised notes, steps split, notes off the beat
KNOB 3	CONTINUITY	low: they jump about the guide's memory; high: they keep to its phrases as played
KNOB 4	SPREAD	how far from the guide's register: low, around its hands; high, from deep bass to high air

SHADOW: each track taken in shadows what the guide sounds, from its own distance behind, at its own pace; now and then backwards or to and fro, resting and coming in again, moved along the scale.

Knob
KNOB 1	DELAY	how far behind: from right behind to 15 s
KNOB 2	DRIFT	how far each one's pace strays from the guide's: a little loose, to half or twice
KNOB 3	VARIATION	how often each changes its way: backwards, to and fro, resting, notes late or left out
KNOB 4	TRANSPOSE	how far it is moved: as played, or a third, fourth, fifth or sixth away

ARPEGGIO: the tracks taken in break the guide's chord (what it holds; a single note over its octaves) into arpeggios, each at its own pace, its own way and in its own octaves, and follow the chord as it changes, at their next step.

Knob
KNOB 1	RATE	a step every 2 s (0) to every 62 ms (100)
KNOB 2	RELATION	how the tracks' paces relate: all one, or twice, half, three in two ...
KNOB 3	MOTION	which way: all up, or each its own (down, up and down, as played, at random ...)
KNOB 4	MUTATE	how much a pattern changes as it repeats
SELECT	RANGE	how many octaves each spans, 1 to 4
ALGORITHM	CHANCE	steps left out and struck twice

Presets

Each engine has 64 presets. SHIFT + ARP opens the PRESETS page of the chosen track's engine; PRESETS chooses a slot. Each preset is named by its sound's family and numbered within it, in the order of the slots: BRASS 1, BRASS 2, STRINGS 1.

• ARP held (or SAVE held) saves the track's sound there, asking before overwriting.
• ARP (or SAVE) loads it and goes back to playing.

Saving silences the audio for a moment.

Snapshots

A snapshot is the state of the machine at one moment. Each session holds 16 of them.

SAVE opens the SNAPSHOTS page: 16 squares, one for each white key. A filled square holds a snapshot; the one last stored or recalled is white.

To	Do this
Recall a snapshot	press and release its white key
Store the current state	hold its white key 0.8 s, or choose it with PRESETS and hold SAVE
Empty a snapshot	hold SHIFT and hold its white key 0.8 s
Set the morph time (0 to 30 s)	KNOB 1
Leave the page	SAVE, or a track button

On this page the white keys do not play notes. Stored snapshots glow on the keys; the last one recalled is lit.

What a snapshot holds. The whole state of the machine. For each track: the engine it plays; the sound on every one of its eight engines, each with its macros and envelope; level, pan, reverb and delay sends, filter, granulator, crush, distortion, octave, the track's transposition, its path, chord mode and modulation; its latched notes and chords; BALLSY's and BRICKLAYER's settings, BRICKLAYER's notes, and whether each plays; and its loops: which loops there are, where each stood against the others, which are taken out, whether they play, and their direction, speed and VARY. For the machine: the reverb, the delay, the scale, the root, the loops' transposition and PLAY ALONG (on or off, its mode, the tracks taken in, the values on its pages). Not stored: the track chosen, EDIT and which page is up.

For example: record a loop and store snapshot 1; record an overdub and store snapshot 2. Snapshot 1 brings back the loop alone and snapshot 2 brings back both. Loops that are in both snapshots keep playing when you switch; a loop that comes back is placed where it stood against the others when it was stored.

A loop that a snapshot holds stays in the FM-1's memory even after you empty the looper (hold REC). It shares the looper's room with what you record: when the looper has no room left, REC says LOOPER FULL. Snapshots that share sounds, latched notes or loops store them once. If there is no room for a new snapshot, the screen says FULL; empty snapshots you no longer need (SHIFT + hold the key).

Morph. With a morph time of 0 (OFF), a recalled snapshot is applied at once. With a longer time, the machine moves to it over that time; the snapshot's square and key blink until it is reached:

• Levels, pans, sends, filter, granulator, crush, distortion, the macros and envelope of a sound that stays, the modulation amounts, LFO rates and fades, the reverb's DECAY, DAMP and MIX, the delay's REPEATS, DAMP and MIX, and the sequencers' speed, rate, harmony and instability change gradually.
• Everything that affects pitch changes at once, halfway through: scale, root, octaves and transpositions. So do the delay's TIME and the reverb's SIZE, the loops, the latched notes, chord mode, the sequencers and their notes, the modulation routings and LFO shapes, and PLAY ALONG.
• A track whose sound changes fades out from a quarter of the way, switches sound halfway and fades back in by three quarters.

Recalling another snapshot during a morph starts a new morph from the current state. The morph runs in the main loop and adds no load to the audio.

Snapshots are saved in the flash with the session (hold SAVE to save). A new session has none.

Sessions

There are 64 session slots; the FM-1 starts with none loaded. SHIFT + SAVE opens the SESSIONS page. A session stores the whole machine: every track's sounds, settings, latched notes and loops, the scale, the delay, the reverb, PLAY ALONG and the 16 snapshots with the loops they hold. Sessions saved under an older Tonitor load with the same sounds after an update. Saving silences the audio for a moment.

Sessions are kept in the FM-1's flash: saving overwrites any projects, presets or samples another firmware left there.

Backing up. The backup page (desktop Chrome, Edge or Opera, over USB MIDI; Tonitor build 47 or later) copies every session and preset to a file on the computer and writes them back. Use it before trying another firmware and after reinstalling Tonitor.

Granulator

Each track's granulator plays grains from the last half second of the track's sound (KNOB 2). Off in the middle; to the left, long, overlapping, drifting grains, sometimes frozen; to the right, short grains, scattered, reversed and stuttered. Each track's granulator has a character of its own, drawn anew at power-on and when a session is loaded. Grains ring on for about two seconds after the notes end.

Distortion

SHIFT + KNOB 3, 0–100 (0 is off): a two-stage drive after the track's filter, granulator and crush, before its sends, so the delay and the reverb receive the distorted sound. Its output is matched to the dry level, so the amount changes the tone, not the loudness.

Delay

A master delay, before the reverb, fed by each track's delay send (SHIFT + KNOB 4); half its echoes also go into the reverb. The repeats are slightly dark and grainy. SEQ once opens its page:

Parameter
TIME	0.02 to 2.0 seconds (shown without the unit); turning it bends the repeats' pitch
REPEATS	the feedback: from one repeat to nearly endless
DAMP	each repeat darker than the one before
MIX	the level of the echoes

Reverb

A plate reverb (after Jon Dattorro), fed by each track's reverb send (KNOB 4). SEQ twice opens its page:

		At the start
SIZE	the room	70
DECAY	0.4 s to about 25 s	65 (about 3.5 s)
DAMP	how fast the highs die	40
MIX	the reverb's level	50

Performance effects

Hold black key 2 and the effects move to values drawn at random; let go and they return to your settings. Each press draws new values. They glide in and out over 50 ms. Black key 2 is lit while it plays.

What moves:

• each track's filter, granulator, crush, distortion, reverb send and delay send
• the master reverb (SIZE, DECAY, DAMP, MIX) and delay (TIME, REPEATS, DAMP, MIX)

Each value is drawn or left as it is by chance, so not everything moves at once. The draws follow the track's generative path: AMBIENT leans to low-pass filters, long dark grains, little crush or drive and more reverb; EXPERIMENTAL to crush, drive, scattered grains and short, bending echoes; OPEN to anything. The master's draws follow the chosen track's path.

Your settings do not change: the knobs, snapshots and sessions keep them. A knob turned while the key is held changes your setting, heard mixed with the random value until you let go.

SHIFT + black key 2 opens the PERF FX page; SHIFT + black key 2 again, SEQ or a track's button leaves it.

		At the start
MIX (KNOB 1)	how far each value moves from your setting towards its random value: 0 none, 100 all the way	50
TRACKS (KNOB 2)	CUR: the current track; ALL: every track	CUR
TRACK (KNOB 3)	the tracks' effects move: ON or OFF	ON
MASTER (KNOB 4)	the master delay and reverb move: ON or OFF	ON

Sessions keep the page's values.

USB audio

Connected to a computer, phone or tablet, the FM-1 is also a class-compliant USB audio input ("FM-1 Tonitor"), 16-bit, at 48 or 44.1 kHz (44.1 kHz is the FM-1's own rate: nothing is converted). GLOBAL SETUP > AUDIO > USB chooses what it sends:

USB	Channels
STEREO	2: the master output, with the delay and reverb (what the headphones hear)
TRACKS	6: tracks 1–6, each mono, after its filter, granulator, crush, distortion and level; before its pan and the master delay and reverb

Both are taken before MASTER, which sets only the headphones' level. No driver is needed, and MIDI works over the same cable. To hear the FM-1 while a computer records it, use its headphone output: a program's own monitoring (Audacity's software playthrough) adds a delay and may break up.

Engines

FM — six operators, DX7 style

Six-operator FM after the DX7 (msfa, the core of Dexed). HOME draws a patch from one of these families and levels it to one loudness:

Family
METAL	bells and gongs, inharmonic
DRONE	spectral drones, slowly beating
BRUIT	noises
IMPACT	struck bodies: thuds, knocks, metal hits, drum skins, debris
ITERATIF	a sound pulsed by its own LFO
SPECTRE	a spectral arpeggio: harmonics lifted one after another by beating
ABYSS	sub-bass rumble, breathing slowly
FRICTION	creaking
CHOIR	vowels
BOWED	a bowed string
HOLLOW	odd harmonics only: a dark pipe
BLOOM	a tone opening over seconds
TIDE	three stacks crossfading under a slow tide
SHARDS	a tone broken by random pitch steps and chopped
STATIC	ring-modulated bands
WIND	breath and gusts over a soft drone
PLUCK	plucked strings
MALLET	struck bars: marimba, vibraphone, kalimba
WARP	anything: odd ratios, long glides, bouncing pitch
GLITCH	broken, mechanical sounds
SHAPER	a tone rolling between odd and even harmonics a few times a second
LADDER	partials entering or dying one by one
REVERSE	a sound swelling while the key is held: tape run backwards
CREEP	a held note slowly leaving its pitch
CLANG	DX7-style bells

GLISSE and RUBBER, families of older builds, are now part of WARP; sounds saved with them load as they were.

ANIMA — a lo-fi synthesizer played by a simulated hand

A port of the anima opcode from Vascular, at half the sample rate. While a key is held, a simulated finger drags figures across a virtual surface; where it is, how hard it presses and how fast it moves change the timbre, never the pitch. HOME draws one of twenty-two kinds: HAZE, VOYAGE, GLASS, BELLS, GOLDEN, BREATH, GRIT, SWARM, TIDE, CHOIR, SHARDS, BOWL, DUST, MACHINE, PLUCK, REED, FOG, ORGAN, BITS, DRIFT, MURMUR and HOWL.

CALIGULA — an organism

After SOMA's LYRA-8, as Mike Moreno's LIRA-8 emulates it (BSD licence): eight cross-modulating oscillators in four pairs, a total feedback, gating LFOs and a short modulated delay, played by a simulated hand that touches the plates while a key is held. It is silent until a key is down and is tuned around the note played; a second key moves it to the new note, and letting go of the last key lets it ring out. It is one organism per track, outside the twelve voices. HOME draws one of ten species:

Species
SPORE	slow swells, held drones, breathing; low
THORN	sharp, deep FM, driven, bursting often
HIVE	quick gates: irregular rhythms, bursts
CARRION	the depths, heavy feedback, a warped delay, surges
VEIL	mostly triangles, light modulation: the calmest
RUST	driven, cross-modulated, surging, sometimes rhythmic
LITANY	a slow choir of unisons and octaves
UNDERTOW	deep, heavy feedback, slow surges
WIRE	high and sharp, clusters, a quick hand tapping
MOTH	soft triangles fluttering through the gates, on a pulse

RUSSOLO — noise, logic and broken buffers

The techniques of Robert Heel's Noisferatu (GPL-3.0), at a low sample rate and bit depth. Like CALIGULA it is silent until a key is down, one organism per track, and a key sets its pitch. HOME draws one of seventeen kinds; the first two macros are the kind's own parameters, the others CRUSH and RANDOMNESS.

Kind
HOLD	sample-and-hold noise
DUST	random clicks through a low-pass
GATES	noise opened and closed by two triangles
CRACKLE	sparse clicks ringing over hiss
NOR, XOR	two oscillators combined bit by bit
RING	two oscillators multiplied
CASCADE	squares modulating squares
CLANG	two triangles at an inharmonic ratio, XOR'd
CHUNKS	a buffer of noise, saw and silence, read at the key's speed
JUMP	the buffer read with random jumps
WANDER	a window wandering through the buffer
BEND	the buffer's addresses bent on a clock
QUAD	four such bendings, switched by chance
BLIPS	decaying triangles on the key's harmonics
WALK	a random walk over a scale from the key
CHORD	triangles on a chord, slowly beating

DRUID — strings and resonant bodies

A port of the resonators of Mutable Instruments Rings by Émilie Gillet (MIT licence): strings, sympathetic strings and modal bodies, plucked, struck, bowed or rattled. Letting go of a key damps the sound by an amount set per sound.

Kind	Resonator	Exciter
PLUCK	string	pluck
BOWED	string	bow
STRUCK	string, stretched partials	strike
SITAR	string, buzzing bridge	pluck
RATTLE	string	dust
HARP	sympathetic strings	pluck
DRONE	sympathetic strings	bow
BELL	modal	strike
BOWL	modal	bow
PLATE	modal	dust

BAYAREA — a West Coast voice

A port of the bayarea opcode of Vascular: an oscillator from sine to saw, frequency-modulated by two sines, a wavefolder, then a low-pass gate (struck) or a sustaining envelope over resonant low-passes, a drive and a bank of resonators, all moved by an LFO.

Kind	Envelope
BONGO	gate	low, short decay
PLUCK	gate	brighter, short to medium decay
CHIME	gate	long decay, resonators
FOLDED	gate	heavy folding
SWELL	sustain	slow attack, long release
DRONE	sustain	slower attack, long release

HIVE — a swarm of oscillators

A port of DigiRust's SWARMER, extended: seven oscillators per voice, each at its own place around the note (an octave, a fifth, a cluster step or an inharmonic partial), each moved by slow LFOs, through a filter with its own envelope.

Kind
SUB	the main oscillator one or two octaves down
LEAD	bright, short attack, resonant
STAB	short, a strong filter sweep
PAD	slow attack, wide detune, long release
DRONE	slower attack, full sustain, long release
WASH	the slowest attack and release, noise, a moving filter
CLUSTER	quarter-tone and semitone steps, slowly beating
METAL	inharmonic partials, struck
SPECTRA	inharmonic partials turning slowly
GROUND	two octaves down, a dense cluster with noise: rumble
AIR	filtered noise and high whistles: wind
TIDES	oscillators gliding apart and back

CLUSTER, METAL, SPECTRA, GROUND, AIR and TIDES are for textures rather than melodies.

OBRADOR — an analog polysynth

An analog polysynth voice after the Oberheim SEM and the two-voice Oberheims, written for Tonitor with OberVave (an Oberheim-style firmware for the FM-1, by zvenson) as its frame of reference. Per voice: two oscillators (saw, pulse or both, band-limited), the second detuned or an interval away, hard-synced or cross-modulating now and then; in the lush kinds a second voice card, detuned against the first; a drive into the SEM's 12 dB filter, its output morphing from low-pass through notch to high-pass, its resonance soft-limited; a second low-pass stage for 24 dB, or the band-pass; filter and amplifier envelopes on analog curves; an LFO that comes in after a delay; and each card's own small offsets of tune and cutoff with a slow drift.

Kind
STRINGS	two cards of saws, a slow attack, a delayed vibrato: the string pad
BRASS	the envelope opening the 24 dB low-pass
PWM PAD	two pulses, their widths moving slowly
BASS	the second oscillator an octave down, the 24 dB low-pass, a plucked envelope
SYNC	the second oscillator synced, its pitch swept by the envelope
NOTCH	the filter near its notch, the LFO moving it: a phasing sweep
METAL	cross-modulation at an odd interval through the band-pass: bells, clangs
DRONE	two cards a fifth or an octave apart, the cutoff and the morph moving slowly
KEYS	a struck filter, no sustain
SWELL	the filter opening slowly under a held chord

Voices and load

The six tracks share two limits: twelve voices, and the time the chip has to compute each block of audio. With a few tracks of light sounds neither is reached. With chords on the heavier engines the processing time runs out first, usually well before the twelfth voice.

Voices

FM, ANIMA, DRUID, BAYAREA, HIVE and OBRADOR take one voice per note from the pool of twelve. A note that is released keeps its voice until its release has faded. When a note finds no free voice, it takes, in this order:

1. the quietest released note still fading, on any track;
2. the oldest held note on its own track;
3. the oldest held note on any track that is not latched;
4. the oldest held note of all.

The voice taken is faded out over about 9 ms. CALIGULA and RUSSOLO take no voices from the pool: each is one organism per track, which costs the same however many notes it plays.

Processing time

Each note costs a share of the audio block, here called points: 100 points is one block's full time on one of the chip's two cores. The chart shows each engine's cost per note, from its lightest family to its heaviest, measured on the FM-1 with Tonitor build 71. CALIGULA and RUSSOLO are charged per track.

Engine	Points per note	Lighter families	Heavier families	Notes held on one track before notes are shed
RUSSOLO	2–3 per track	all alike		any number
FM	1–6	IMPACT, MALLET, METAL, PLUCK, CLANG (1–4)	ABYSS, CHOIR, BOWED, BLOOM, TIDE, STATIC (5.6)	12 (all the voices)
OBRADOR	7–13	METAL, KEYS, NOTCH, SYNC (7), BASS (8)	PWM PAD, BRASS, DRONE (12–13)	8 (PWM PAD)
ANIMA	8–13	PLUCK, BELLS, BITS (8–9)	FOG, BREATH, GOLDEN (12–13)	9 (FOG)
BAYAREA	9–11	PLUCK, BONGO (9)	SWELL (11)	8 (SWELL)
DRUID	9–16	BELL, PLATE (9)	PLUCK (16); HARP and DRONE (26–28)	3 (HARP)
HIVE	15–21	SUB, METAL, SPECTRA, AIR, TIDES (15–16)	CLUSTER, WASH, PAD (20–21)	5 (CLUSTER)
CALIGULA	18–23 per track	SPORE, LITANY (18–19)	RUST, HIVE, MOTH (22–23)	any number

The last column was measured with twelve notes held on one track, the delay and reverb on. A note costs the same while its release fades as while it is held. Decaying families (BAYAREA's PLUCK, BONGO, CHIME and FOLDED, DRUID's SITAR, FM's IMPACT, PLUCK and MALLET) cost their full amount only while they ring.

Add up the points of everything sounding at once. Up to about 100 the audio keeps up; with all six tracks playing, up to about 80, because each track's mixing and effects take their share too. Some sums, measured:

What plays	Points	Result
FM ABYSS, 12 notes on one track	67	clean, load 75 %
six tracks, one note each on FM, ANIMA, CALIGULA, HIVE, DRUID, BAYAREA	about 80	clean, load 86 % (peaks 96 %)
DRUID HARP, 4 notes	111	at the limit: an occasional late block
six tracks, two notes each on the same six engines	about 135	overloaded: six notes shed
ANIMA FOG, 12 notes	about 150	overloaded: three notes shed

The load here is the share of each block's time the audio takes on the first core, with the second core taking part of the voices. The rest of the time goes to the keys, the screen and USB.

When the load is too high

Before each block, Tonitor estimates its cost. If it will not fit, released notes still fading are let go first, the quietest first, then a CALIGULA's ring-out with no key held, each over about 6 ms. A held note is never let go at this stage.

If the audio is late anyway, two half-buffers in a row above 85 %, the same order applies, and then the oldest held note that has sounded for at least 1.5 s is faded out. A latched note and a note just played are never let go. Until enough notes have gone, the output can crackle.

Planning the tracks

• Play chords and dense parts on FM, CALIGULA or RUSSOLO. Twelve FM notes cost less than four DRUID HARP notes. CALIGULA and RUSSOLO cost the same with one note or ten.
• Keep HIVE, DRUID's HARP and DRONE, and the heavy ANIMA and OBRADOR families to single notes or two-note intervals, especially when other tracks are playing. One DRUID HARP or DRONE note costs as much as five FM notes.
• Choose the lighter family when it serves the part. Within ANIMA, OBRADOR and HIVE the heaviest family costs 40 % to 100 % more than the lightest (the table above).
• Shorten the release on heavy tracks. A fading note costs as much as a held one, so a long release on a HIVE pad keeps paying for every note played. The ENVELOPE page's RELEASE sets it per track.
• Latch only what must stay. Latched notes are never shed, so under load the other tracks' notes go first.
• Count the loopers. Loop notes use the same voices and the same time as played notes, and several loops on one track sound at once.
• The reverb costs about 7 points while any track sends to it, once for all tracks; the delay costs under 1. A track's filter, granulator, crush and distortion each cost a few points at most.
• If the sound crackles, let go of notes first, then move the densest part to a lighter engine or family, or silence a track you are not listening to.

Building from source

Once:

./setup.sh

It makes a Python environment in .venv (Pillow, mido, python-rtmidi), downloads JieLi's Linux toolchain to ~/.jieli/toolchain, and fetches the three files of the JieLi AC79 SDK the package needs into ~/fw-AC79_AIoT_SDK. On macOS the toolchain runs in Docker, so Docker Desktop must be running to build. ./setup.sh --font also fetches Atkinson Hyperlegible (the Braille Institute's typeface for low vision), for smoother large type than the default Terminus.

Then, with the FM-1 connected by USB and switched on:

./install.sh

It builds build/tonitor.fwsc and installs it over USB-MIDI. ./install.sh --info tells what the connected FM-1 runs; ./build.sh only builds.

Testing without the FM-1

tests/run_tests.sh

needs only clang, Python and (for the browser installer) Node. It checks the firmware for anything the chip cannot run (it has no FPU and no compiler runtime), then runs the real DSP, sound generators, mixer, loopers, sessions and screen code on the computer, and the browser installer against a simulated FM-1:

• build/sounds/ — WAVs of every engine, family and path, and mix.wav, the six tracks entering one after another;
• build/screens/ — the screen in its states, as PNGs.

How it is built

firmware/src/tonitor.c is the single compilation unit: fm.c (FM, around msfa's fm6_core.c), anima.c (ANIMA), cal.c (CALIGULA), russolo.c (RUSSOLO), druid.c (DRUID), bayarea.c (BAYAREA), hive.c (HIVE), gran.c (the granulator), reverb.c, layers.c (the six tracks, the loopers, the mix; each block the voices, the organisms and the master effects are dealt to the FM-1's two cores, audio_worker.h and hal/fm1_multicore.h), ui.c (panel and screen), sessions.c, gfx.c, dsp.h (fixed-point helpers), main.c (boot, interrupts). Based on Felucca and earlier open FM-1 firmware work: firmware/hal/, firmware/loader/, usb.c, ota.c, recovery.c, lcd.c, libc.c, the build checks and the installer. The website and the browser installer are in docs/ (served by GitHub Pages); tools/make_site.py builds its pages from site/ (home, install), this README (the manual) and CHANGELOG.md and publishes build/tonitor.fwsc for the installer.

Licence

• The firmware is free software under the GNU General Public License, version 3 only (GPL-3.0-only, LICENSE): it is a work based on GPL-3.0 code (see LICENSING.md). The browser installer (docs/js/fm1ota.js), a port of Felucca's installer, is GPL-3.0 too.
• The website, the logo and the documentation written for Tonitor (docs/ except docs/js/fm1ota.js and the firmware package, and this README's text) are under the MIT licence (LICENSES/MIT.txt).
• Third-party parts keep their own licences: msfa (Apache-2.0), the LIRA-8 architecture (BSD 3-clause), Noisferatu's techniques (GPL-3.0), Rings (MIT), the fonts (SIL OFL 1.1), the JieLi SDK files placed in the package (Apache-2.0).

LICENSING.md lists every file and its licence.

Credits

Tonitor is by Nuno Zimas. It stands on the work of others:

• Felucca by Leo Kuroshita / Hügelton Instruments — the hardware track, USB stack, update loader, rescue mode and installer that made an FM-1 firmware possible at all.
• msfa by Google Inc. and Pascal Gauthier (Apache-2.0), from Dexed, in Felucca's integer port — the FM.
• ANIMA is ported from the anima opcode of Vascular.
• CALIGULA follows the architecture of LIRA-8 by Miguel Moreno (BSD), an emulation of SOMA Laboratory's LYRA-8.
• RUSSOLO re-makes, in fixed point, the techniques of Noisferatu by Robert Heel (GPL-3.0).
• BAYAREA is ported from the bayarea opcode of Vascular.
• HIVE is ported from the SWARMER machine of DigiRust.
• DRUID is a fixed-point port of the resonators of Mutable Instruments Rings by Émilie Gillet (MIT).
• Atkinson Hyperlegible by the Braille Institute (SIL OFL 1.1) and Terminus (SIL OFL 1.1).

M-VAVE and FM-1 are trademarks of their owner, used here only to say which device Tonitor runs on.

Disclaimer

Tonitor is an unofficial firmware. It is not made, endorsed, approved or supported by M-VAVE or by the maker of the FM-1, and it is not affiliated with them.

Installing it replaces the device's original firmware and may void any warranty that applies to your FM-1, if any applies at all; check the terms of your warranty before installing. Installing any firmware carries a risk: an interrupted or failed update can leave the device unable to start until it is recovered (see Installing), and saving sessions overwrites data that other firmwares may keep in the same flash area.

The software is provided "as is", without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and non-infringement. In no event shall the authors or contributors be liable for any claim, damages or other liability — including damage to your device, loss of data, or loss of the use of the device — arising from, out of or in connection with the software, its installation or its use. You install and use it entirely at your own risk. See also sections 15 and 16 of the GPL.