ChooChooTracker User Manual

ChooChooTracker is an 8-track music tracker for handheld consoles.

It follows the classic LSDj workflow and navigation system, with several sound design options:

• AY chip emulation
• Mutable Instruments Braids, Plaits and Plaits-Alt oscillators, with a multimode filter
• PCM samples, single-cycle waveforms and wavetable oscillators, with a multimode filter
• aChChid, a versatile acid synth based on Open303
• Bogie, a native 12-model drum synthesiser with a multimode filter
• MonkSynth, a vocal synthesiser with ten-voice unison and stereo delay
• MME, a two-oscillator multi-modulation synthesiser with a multimode filter
• Sintered, a native six-model experimental digital drum synthesiser

1. Installation and files

ArkOS / PortMaster

Install choochootracker.zip through PortMaster, or copy the extracted package to the console’s ports directory. Start ChooChooTracker from the Ports menu. On the RG353V with ArkOS, use the console’s + / - buttons to adjust output volume during playback.

Miyoo Mini / Mini Plus (Onion OS)

Extract the MiyooPorts archive at the root of the SD card so that its Roms/PORTS/ folders merge with Onion’s existing folders. Start ChooChooTracker from the Ports menu after refreshing the collection. Back up the app’s projects/ folder before replacing an existing installation.

The same MiyooPorts build scales the tracker interface to the detected screen size on the original Mini, Mini Plus, Mini V4 and Mini Flip. The screen size is detected at each launch, including after moving an SD card between models. If a Mini V4 still shows wide borders, update Onion OS so it can switch the display to its higher resolution when launching the port.

Project loading time can vary with the instrument types used in a song. If startup or project loading seems unusually slow, report how long each takes, along with the console model and Onion OS version.

Raspberry Pi OS 64-bit

Extract the Raspberry Pi AArch64 archive, install the SDL2 runtime (sudo apt install libsdl2-2.0-0), then run ./chipnomad.sh from the extracted directory. Keep the packaged instruments and other assets beside the executable.

Windows

Run choochootracker.exe with SDL2.dll and libwinpthread-1.dll in the same directory. Press ALT + ENTER to toggle fullscreen. The window is resizable; the image scales while keeping its original aspect ratio.

Web

The browser version refreshes its display at about 30 FPS and uses a fixed 1024-frame audio buffer to give audio more time between callbacks. Older saved buffer settings are adjusted automatically; projects and other settings are preserved. Input polling and app timers keep their usual cadence.

Directory configuration

The current project is autosaved every minute and on exit as autosave.cct next to the app. If the autosave cannot be loaded at startup, the title screen says so and the demo project opens instead. The unreadable file is kept as autosave.cct.unreadable (then -2, -3, …) so later autosaves never overwrite it, and the work in it can still be recovered.

Project saves and autosaves include loaded or recorded sample audio.

If a manual save or autosave fails while the app is open, an error appears on screen. Keep the project open and retry after checking the working folder and free storage.

2. Controls

ChooChooTracker works best with a gamepad that has a D-pad, 2 analogue sticks and 7 buttons.

Mappings can be changed in Settings > Controls > Key mapping, including on Android with an external gamepad. On PortMaster, save a remap with Done, then release the button before continuing in Settings. Desktop layout defaults use QWERTZ only for QWERTZ regions; Polish keyboards keep the standard QWERTY defaults.

Windows, web, and Android users can also use a game controller. On Android, touch controls appear automatically when no gamepad is connected: in portrait they sit below the tracker, with a square D-pad, A/EDIT, B/OPT, START/PLAY and SELECT/SHIFT controls, then a separate Live/Motion section with two modulation sticks and momentary REC/DEL controls. Landscape keeps the D-pad on the left and the action buttons on the right. Android can keep projects and samples in private app storage or a folder chosen in Settings > Working folder. The direct APK starts with a shared folder on Android 11 and later, but you can change it from that setting; on Android 10 it asks you to choose a folder. Use the Android file picker to import .cct projects and .wav samples, and to choose where WAV exports are saved. If an Android import or export fails, a message appears with the storage checks to try.

Navigation

• Use [UP/DOWN/LEFT/RIGHT] to move the cursor. It underlines the current field; with Settings → Graphics → Cursor set to Brackets it frames the field with four corner brackets instead, which briefly dim when the cursor lands somewhere new so it is easy to find after moving or switching screens.
• Hold SELECT + [DIRECTION] to move between screens.
• SELECT + [LEFT/RIGHT] also exits branch pages to the neighbouring MSCPIT screen, like Instrument Pool: Project/Settings (including Settings submenus) lead to Mixer/Chain; Groove to Chain/Instrument; Modulation/Insert FX to Phrase/Table; AY Wavetable to Instrument/Table. At the left edge, Reverb/Delay return to Mixer with SELECT + LEFT. Existing vertical navigation remains.
• Hold OPT + [DIRECTION] for screen-specific navigation.
• On a value, use EDIT + [LEFT/RIGHT] for fine changes or EDIT + [UP/DOWN] for coarse changes.
• On a Modulation Destination, LEFT/RIGHT cycles the available destinations directly; tap EDIT to open its grouped menu.
• Tap EDIT to enter a value or activate a command.
• Double-tap EDIT to create a new chain, phrase or instrument where supported.
• Holding a direction repeats after the delay configured in Settings.

Selection and clipboard

• SELECT + OPT enters selection mode and cycles through useful selection ranges.
• Use [DIRECTION] to extend the range.
• OPT copies the selection.
• OPT + EDIT cuts it.
• SELECT + EDIT pastes it.
• EDIT + [DIRECTION] edits the selected cells together.

On the Phrase screen, with a selection active, the note column can be filled with rhythm patterns:

• OPT + LEFT fills the selection’s note cells with a fixed 16-step pattern and advances to the next pattern on every press. After the last pattern the notes are erased and the cycle starts over. Patterns are aligned to absolute phrase rows, so a partial selection only receives the steps that fall inside it.
• OPT + RIGHT fills the selection’s note cells with a randomized pattern of 3-8 notes (7 and 8 are less likely), cycling indefinitely while OPT is held.
• OPT + UP mutates the notes already placed in the selection: every press picks 1-3 of them and shifts each by a random amount within an octave (small shifts are more likely than extreme ones). With Note Lock active the shifted notes are snapped back into the scale; Sampler instruments with Slice on stay chromatic. Nothing is erased: the 8th press restores the notes the selection held when the cycle started, then the cycle starts over.
• OPT + UP on a selection covering the volume column only (no note, instrument or FX cells) randomizes velocities instead of mutating: the first press applies the Minimal pattern (each volume shifts by up to +-20), the second Medium (up to +-50), the third Random (completely random values), and the fourth restores the volumes the selection held when the cycle started. Releasing OPT resets the cycle to Minimal. Rows without a volume are left untouched.
• OPT + DOWN spreads the placed notes of sliced Sampler instruments in the selection into a chromatic run: each instrument’s first note (highest in the sequencer) keeps its value and every following note of that instrument rises one semitone above the previous one, turning a stack of identical notes into consecutive slice triggers. Several sliced instruments spread independently from their own first notes, notes on instruments without slicing are left untouched, and the result is never snapped to the project scale. The last note the spread writes becomes the last note used in note input, so continuing the run manually picks up the next slice. A selection holding only sliced instruments spreads on every press; when non-sliced notes are present too, the spread runs on the first press and the random arp takes over those notes from the second press on.
• OPT + DOWN on a selection without sliced-instrument notes is a random arpeggiator for the notes already placed there. A chord is picked from the CRD palette - 3-note chords for selections of 1-2 notes, 3+ note chords for 3, any chord for 4 or more - with its root on a random note of the project scale inside the selection’s register (any chromatic note when the scale is off or the track is excluded from it), and its tones are quantized into the scale like playback does for CRD. Every press re-spreads the chord across the placed notes: randomized, lowest-to-highest, highest-to-lowest, then up-and-down; the 5th press restores the original notes and the next press picks a fresh chord. The chord name shows in the status bar while the arp is active, no notes are added or removed, and releasing OPT resets the whole process.
• Every fill press erases the selection’s notes before writing, and placed notes carry the last used instrument; releasing OPT resets the cycles to their first step.
• While a selection is active and no other message is showing, the status bar rotates a reminder of these combos every 2 seconds: EDIT + DIR = batch note edit, Double-tap EDIT: resample selection, OPT + LEFT = pattern fill, OPT + RIGHT = random fill, OPT + UP = mutate/randomize velocity and OPT + DOWN = random arp/slice spread. Entering or leaving selection mode restarts the rotation; any action message replaces the hint until it expires.

Playback

• PLAY starts from the cursor. Press it again to stop.
• You can edit notes, instruments and chains while playing; changes are heard at the next sequencer tick.
• SELECT + PLAY starts all tracks when used outside the Song screen.
• EDIT + PLAY previews an instrument from the Instrument Pool.

3. Song structure and screen map

Hold SELECT + [DIRECTION] to move between screens.

The main navigation row is:

R P   G M
M S C P I T
D S     P W

Central row:

• M: Mixer (branches to Reverb, Delay)
• S: Song (branches to Project, Settings)
• C: Chain
• P: Phrase (branches to Groove)
• I: Instrument (branches to Modulation and Instrument Pool)
• T: Table (branches to the AY Wavetable editor)

Top row:

• R: Reverb
• P: Project
• G: Groove
• M: Modulation

Bottom row:

• D: Delay
• S: Settings
• P: Instrument Pool
• W: AY Wavetable editor

A ChooChooTracker song follows this hierarchy:

Song -> Chain -> Phrase row -> Note + Instrument + FX

A song has 8 tracks. Each track contains a sequence of chains, and each chain contains a sequence of phrases. Phrases are 16-step sequences of notes. A note contains a pitch, an instrument, a velocity and up to 3 track FX. An instrument is the thing that makes the sound.

Optional 16x24 fonts and NostromoAmberDa2

Settings → Load font → fonts/Pixel16x24 contains TechMonoAudit (converted from Share Tech Mono), Departure Mono, Spleen and Cozette. Each supplies the complete printable ASCII set in 16×24 cells for a 640×480 display. Pixel-built fonts keep their native pixels or integer scaling with padding; Cozette remains smaller because doubling its 13-pixel ink height would exceed the cell. The NostromoAmberDa2 theme is available through Settings → Edit color theme → Load. It retains the Nostromo amber background and informational text, with red primary text, darker orange values and a teal cursor. Loading the assets does not change your selected font or theme. See the accompanying README.txt for attribution and licenses.

The themes folder also includes Bb22200, Eclair, Greydark and Reddeep. NostromoAmberDa2 is in the IDEColorThemes subfolder.

Project page spacing

The Project page puts the application version on its own line and separates Load, Save, New, Export and Manage from the project metadata with blank rows. Cursor positions and touch targets follow the displayed fields; project settings and file operations are unchanged.

Audio display telemetry

Audio readouts use a UI-owned snapshot of the final mix and individual track contributions. Track samples and stereo peaks are captured after track level and tilt, before shared effect returns and master gain. Monitoring does not change the audio signal. The audio callback publishes fixed-size snapshots without locks or allocation; display history spans about 21 ms.

Persistent waveform

Graphics → Persistent waveform is OFF by default. Tap EDIT to toggle it, or use EDIT + direction; the choice is saved as an app preference. OFF restores full-height pages and the existing instrument waveform previews. When enabled, a two-row waveform above editing pages shows the final mix summed to mono. Instrument and Modulation pages show the output of a track using the selected instrument; the selected Song track wins if several tracks use it. Project, Settings, wavetable and popups keep their full-height content. Lists scroll within the remaining rows. Instrument footers retain ADSR/sample previews, and Modulation fields are compacted to keep all controls accessible. Its touch targets follow the displayed fields in both waveform modes.

Playback piano

A code-drawn pixel piano below the eight right-side track rows lights sounding pitch classes, folded into one octave. It includes chord notes and respects muted/stopped tracks. The outline uses the theme value color and all active keys use the waveform color; idle keys have dark fills and subtle shadows. Its grid uses integer scaling and fixed-width borders. The piano is a playback indicator, not a note-entry control. Popups and the wavetable editor keep their own content in this area.

Mixer meters

The Mixer shows adjacent L/R peak bars for each track after its PAN and tilt, before shared effects and master gain. The meter spans -48 to 0 dBFS and decays between updates. Its lower and middle bands use theme colors, while the top band is bright red near full scale.

4. Song, Chain and Phrase

Song

The Song screen contains 8 columns, 1 per audio track. Each cell refers to a chain. A song can contain up to 256 rows (00-FF).

Tracks run from left to right, while their chains run vertically. Each track is independent, and chains can contain from 1 to 16 phrases, so tracks can drift out of sync. Design your chains to stay together, or let them wander if that is what the track needs.

It is common to reserve 1 chain for empty phrases, usually 00 or FE.

You can keep multiple sub-songs in a project by creating “islands”: sections separated by empty rows.

Live Mode

Double-tap OPT to enter or leave Live Mode; LIVE replaces the Song title. The switch happens a moment after the second tap, so tapping OPT 3 times adds a highlight without entering or leaving Live Mode. In Live Mode, PLAY starts the selected chain on its own track when that track is stopped. On a playing track, it queues the selected chain for the next chain boundary; press PLAY twice for an urgent change at the next phrase boundary. A selected empty Song cell queues a quantised stop instead. + marks a queued chain, ! an urgent chain and - a queued stop.

Select one Song row across several columns to queue or stop those tracks together. Multi-row selections are deliberately rejected. Live queues are cleared while a Song range loop is active. Live is a performance mode and is not saved in the project.

Controls

• OPT + [UP/DOWN]: jump 16 positions up or down
• Select a range, then use SHIFT + EDIT: shallow-clone the chains while keeping their original phrases
• Select a range, then double-tap SHIFT + EDIT: deep-clone both the chains and their phrases
• Select a range, then use EDIT + [UP/DOWN]: move the selection up or down
• Tap OPT 3 times: add or remove a highlight for visual organisation
• OPT + SHIFT: mute the current track or selected columns (release OPT first to keep the mute active)
• OPT + PLAY: solo the current track or selected columns (release OPT first to keep the solo active)
• OPT + [LEFT/RIGHT]: solo every track to the left or right of the current track
• Select a range, then double-tap EDIT: open the BOUNCE TO SAMPLE screen (see Bounce below)

Stopping playback and changing mute or solo use a short 3 ms output correction to reduce clicks. This also covers unmuting and clearing solos during playback.

Bounce

Select a range of Song rows and columns, then double-tap EDIT to open the BOUNCE TO SAMPLE screen. The bounce includes every selected track: tracks whose first chain starts later in the selection wait silently and join at their first chain, so the file contains all selected tracks’ chains.

The screen offers:

• File name: edit with the character keyboard. When the screen opens, the next free sequence number (001, 002, …) is proposed here: the first number whose .wav file does not exist yet in the export folder. Edit it freely — the name is used as-is. If a file with that name already exists, a _001, _002, … suffix is added so existing files are never overwritten. The counter resets when you load or create a project.
• Sample rate and Bit depth: the same options as the export screen
• Include in a sample name: three checkboxes that prepend context tags to the file name when Start is pressed (all off by default):
  • [BPM] — the project’s current tempo, e.g. [120]
  • [Key] — the project’s root note and scale, e.g. [Cmaj], [F#min Pent]
  • [Bars:Beats:16ths] — the rendered length of the bounce: one phrase equals one bar (16 sixteenths), a beat is 4 sixteenths. Full phrases show only bars, e.g. [2]; partial phrases show [0:2] (two beats) or [0:1:3] (one beat plus three sixteenths). For multi-track bounces the longest track decides. A selection ending mid-beat counts one sixteenth less: the last selected row is the cut point, so its note-off lands at the end of the previous sixteenth.
  • Tags are applied in the order [BPM][Key][Length] before the file name.
• Start: render the selection to a WAV file in the export folder (see Export location under Project screen)
• Cancel: return without bouncing

While the bounce renders, OPT cancels it. When the bounce completes or is cancelled, the screen you bounced from returns.

On desktop, key jazz also brings direct hex-index typing plus Phrase-style Shift+arrows selection, Delete/Backspace/Insert and Ctrl+C/X/V here — see Key jazz.

Chain

A chain is an ordered list of 16-step phrases with optional transposition. It can contain up to 16 phrases, and the same phrase can appear more than once. The 2nd column sets the transposition in semitones.

An asterisk (*) appears next to a chain that is reused in the project. You can clone chains from the Song screen.

Controls

• OPT + [LEFT/RIGHT]: move between tracks
• OPT + [UP/DOWN]: move between chains in the current track
• Select a range, then use SHIFT + EDIT: clone phrases
• Select a range, then double-tap EDIT: open the BOUNCE TO SAMPLE screen for the selected chain rows of the current track (see Bounce under Song)

On desktop, key jazz also brings direct hex-index typing here — see Key jazz.

Phrase

A phrase is the track pattern in a traditional step sequencer.

A phrase is 16 steps long, with 1 row per step. Each row contains a note, an instrument, a volume from 00 to 7F, and FX columns. Notes use tracker notation such as C-4 (note and octave).

To stop a note, insert NOTE OFF, use the kill-note FX, or play another note with no instrument set.

When a chain contains several phrases, the Phrase screen works like a continuous pattern editor. Moving below row F or above row 0 opens the next or previous phrase in the chain.

An asterisk (*) appears next to a phrase that is reused in the project. You can clone phrases from the Chain screen.

The FX selector shows common commands plus those supported by the instrument on that row. This avoids a long global list of engine-specific commands. ChooChooTracker supports more FX than ChipNomad.

Controls

• OPT + EDIT on an empty note: insert NOTE OFF
• EDIT + [UP/DOWN] on an FX name column: open the FX selection screen
• OPT + [LEFT/RIGHT]: move between tracks
• OPT + [UP/DOWN]: move between phrases in the current chain
• Select a range in the instrument column, then use SHIFT + EDIT: clone instruments
• Select a range, then use EDIT + [UP/DOWN]: rotate the phrase rows
• Select a range, then double-tap EDIT: open the BOUNCE TO SAMPLE screen for the selected phrase rows of the current track (see Bounce under Song)

Key jazz (desktop only)

Press Esc on the Phrase screen to toggle key jazz, a QWERTY piano-style note entry mode (like m8c):

• Z S X D C V G B H N J M and Q 2 W 3 E R 5 T 6 Y 7 U I 9 O 0 P type notes chromatically across two-plus octaves, using each key’s physical position so the layout is the same on AZERTY, QWERTY and QWERTZ keyboards.
• Each keypress writes the note on the current row and moves to the next row.
• [ / ] shift the octave.
• Shift + arrows select a range of rows and columns; a plain arrow afterwards clears the selection.
• Ctrl+C / Ctrl+X copy or cut the selected columns, or the current row’s note/instrument/volume if nothing is selected; Ctrl+V pastes at the cursor.
• Delete removes the whole row(s) (every column) and shifts the rest of the phrase up to fill the gap; the cursor stays on the same row.
• Backspace removes the element under the cursor in the current column only (or the selection’s columns, if one is active), shifts whatever is below it up to fill the gap, and steps the cursor back one row, like a text editor.
• Insert inserts a blank row, pushing the rest of the phrase down.
• Ctrl+S saves the project. Outside key jazz, Ctrl+S does nothing.
• Esc again turns key jazz off.

While key jazz is on, it takes over the note keys entirely on the Phrase screen, including Edit/Opt/Motion shortcuts that share those keys — turn it off with Esc to use them again.

Key jazz also works, independently toggled with Esc, on:

• Song and Chain: type a chain’s or phrase’s hex index directly (0-9, A-F) instead of incrementing with Up/Down. The first digit typed on a cell replaces its value; further digits typed without moving shift into it (typing “3” then “F” sets 3F). On Song, Shift+arrows select a range, Delete removes whole row(s) and shifts the rest up, Backspace removes the current/selected column(s) and shifts what’s below them up, Insert inserts a blank row, and Ctrl+C/Ctrl+X/Ctrl+V copy/cut/paste the selected rows (or the current row if nothing is selected) - the same structure-editing shortcuts as the Phrase screen. This takes over Shift, so Shift+Right/Up no longer jump to Chain/Project while key jazz is active here - Esc to get those shortcuts back.
• Every screen with a text field: type directly on the keyboard instead of using the on-screen virtual keyboard. This covers the Project file name, title and author, the instrument name, the color theme name, the pitch table name, the bounce file name, and the name dialogs (enter name, create folder). Backspace works like a normal text field; Shift types uppercase letters. Esc toggles it on all of these screens at once, and the virtual keyboard still opens normally when key jazz is off.

5. Instruments

All instruments have a few common parameters:

• Instrument type
• Name, up to 15 characters
• Default table speed, in ticks per table row
• Transpose on or off
• EQ bank (see EQ below)

Each instrument has a default table with the same number in the 00-7F range. You can use these as auxiliary tables, but keeping auxiliary tables in the 80-FE range avoids conflicts and confusion. Tables are among the main sound design tools in ChooChooTracker.

Controls

• OPT + [LEFT/RIGHT]: move between instruments
• EDIT + PLAY: preview the instrument
• SHIFT + OPT: copy the instrument
• SHIFT + EDIT: paste the instrument

EQ

A project has 128 three-band EQs, numbered 00-7F, and every instrument except MIDI Out can use one of them. The EQ value under PAN and VOL at the top of the Instrument screen is the instrument’s EQ number, or -- for none:

• EDIT or EDIT + d-pad on -- picks the first EQ that no instrument uses yet. The instrument uses it straight away; every EQ starts flat.
• EDIT + [LEFT/RIGHT] changes the number by 1, EDIT + [UP/DOWN] by 16, and EDIT + OPT sets it back to --, so the instrument has no EQ.
• A short press of EDIT on a number opens that EQ. OPT or SHIFT + LEFT returns to the instrument.

Several instruments can share an EQ: changing it changes all of them. The top of the EQ screen shows which instruments use it.

The EQ screen draws the combined frequency response from 20 Hz to 20 kHz, with grid lines every 6 dB. Each band has a coloured dot, and the selected band’s own shape is shaded. Below the graph are the settings of the three bands:

• Band: hold EDIT and use the d-pad to move the band’s dot. LEFT/RIGHT changes the frequency; UP/DOWN changes the gain, or the resonance of a cut.
• Shape: Off, Lo cut, Lo shelf, Bell, Hi shelf or Hi cut. Cuts fall at 12 dB per octave. Off skips the band.
• Freq: 20 Hz to 20 kHz in quarter-tone steps; EDIT + UP/DOWN moves half an octave.
• Gain: -15 to +15 dB in 0.5 dB steps; EDIT + UP/DOWN moves 3 dB. Cuts have no gain.
• Q: the width of a bell or shelf (higher is narrower), or the resonance of a cut. 0.71 is a gentle shape with no peak.

EDIT + OPT returns a setting to its default; on Band it resets the whole band. EDIT + PLAY previews the instrument and PLAY plays the phrase, so you can adjust the EQ while listening.

The EQ works on the track the instrument plays on, before the track’s insert effects and sends. If a track changes to another instrument, that instrument’s EQ takes over. An instrument keeps its EQ number when you change its type. Saving an instrument as a .cni file includes its EQ settings; loading it puts them in an unused EQ of the project, or in an EQ that already has the same settings.

AY Classic, AY Plus and AY Sample

These are the original ChipNomad AY/YM engines. AY Classic exposes hardware-style tone, noise and envelope controls. AY Plus adds software oscillators and richer modulation. AY Sample reproduces a sample through AY-style volume levels and is distinct from the Sampler engine.

AY Classic

This is a legacy instrument type from ChipNomad v1.0.0. The newer AY Plus instrument offers more features.

AY Classic instruments have these parameters:

• Mixer: tone on or off, noise on or off, envelope shape (0-F)
• Volume: software-generated ADSR envelope
• Automatic envelope period: on or off, with a rate from 1:1 to F:F

AY Quality in Settings affects only AY/YM rendering. It does not change Braids, Plaits or Sampler quality. Sample dithering applies to AY Sample quantisation.

See the ChipNomad AY-3-8910 documentation for chip details.

AY Plus

AY Plus applies classic synthesiser concepts to AY-3-8910/YM2149F sound design. You can think of AY as a synthesiser with 5 oscillators:

• 3 square wave tone oscillators
• 1 noise oscillator
• 1 amplitude envelope generator which can be used as an oscillator

Under this model, each instrument has 3 hardware oscillators: tone, noise and envelope. AY Plus adds a 4th, software oscillator. Updating AY registers faster than the project tick rate opens up more sound design options. Because of the way AY works, the oscillators are mixed using ring modulation. Try different pitch offsets, detuning and oscillator combinations to see what falls out.

Each tonal oscillator can be tuned independently with pitch and fine tune offsets.

Software oscillator types and their parameters:

• Pulse - square wave with controllable pulse width
  • FM Depth - simple FM depth
  • Pulse width - the full range is 00-FF, while the number of steps is set on the Project screen
  • Pulse low - controls the low value in a repeating pair whose high value is always 15
• Sync Tone - hard-sync effect for the tone oscillator
  • FM Depth - simple FM depth
• Sync Env - hard-sync effect for the envelope oscillator
  • FM Depth - simple FM depth
  • Pulse width - duration ratio between the 2 shapes in the envelope pair
  • Envelope Pair - 2 envelope shapes to switch between
• Wavetable - 32-step wavetables, edited on the Wavetable screen
  • FM Depth - simple FM depth
  • Wavetable index
• Tone FM - simple FM-like effect for the tone oscillator
  • FM Depth - tone FM depth
• Env FM - simple FM-like effect for the envelope oscillator
  • FM Depth - envelope FM depth

Pulse and Wavetable software oscillators cannot be used with the Envelope oscillator. The Envelope oscillator switches off automatically.

Simple FM switches quickly between 2 period values, 1 lower and 1 higher. This is similar to using a square wave as an FM modulator. Pulse, Sync Tone, Sync Env and Wavetable use a 1:1 ratio between the FM carrier and modulator. Tone FM and Env FM can imitate other ratios through software oscillator pitch offsets.

AY Sample

You can load mono or stereo WAV files at 8-bit, 16-bit, 24-bit or 32-bit. They are converted to 8-bit and truncated to 16 KB. This limit matches the RAM page size of the ZX Spectrum.

AY plays samples through fast writes to the volume register. Its output is unipolar, so samples need to be “lifted to zero” for cleaner playback. This removes end-of-sample clicks and improves quiet tails.

AY has 4-bit DAC resolution with a non-linear volume scale, so 8-bit samples are converted to 4-bit during playback. The Sample dithering option in Settings can improve the perceived bit depth. Dithering is not practical on retro platforms such as the ZX Spectrum and Atari ST, so leave it off when writing for real hardware or chasing a crunchy lo-fi sound.

Samples behave like another AY Plus software oscillator, but their extra parameters make them easier to handle as a separate instrument type.

Sample parameters:

• Sample rate - playing a sample at its native rate produces a C-4
• Sample start
• Sample length
• Sample loop start
• Sample pitch offset
• Sample fine pitch offset

The Tone and Noise oscillator sections match those of AY Plus. Because of the way AY works, all oscillators are mixed using ring modulation.

Braids

Braids provides 47 synthesis models. Its main controls are:

• Model: oscillator or synthesis algorithm
• Timbre and Color: model-dependent macro parameters
• Filter: additional LP/BP/HP filter, 12 or 24 dB slope, cutoff and resonance
• ADSR: attack, decay, sustain and release

Tap Model to choose from categorised model lists.

Parameters

Timbre and Color depend on the selected model. Refer to the original Braids manual from Mutable Instruments for the full model list and details, or just play by ear.

VCF and VCA

Braids feeds the standard ChooChooTracker multimode filter and ADSR envelope.

Settings

Global Braids settings are available in the app settings:

• BITS: reduces output resolution
• DRFT: adds oscillator pitch instability
• SIGN: reproduces the original Braids waveform-imperfection algorithm

aChChid

aChChid is a monophonic acid bass engine based on Open303. Square and Saw use its native TB-303 oscillator, filter, envelope and accent behaviour. Braids and SID replace only the oscillator, then continue through the same 303 filter and amplifier path. Braids offers Model, Timbre, Color and Shaper. SID offers Shape (triangle, saw, pulse, noise or the four SID waveform combinations), Width (pulse width) and Shaper. Width affects only forms containing a pulse. Shaper progresses from soft saturation into wavefolding. SID does not use the SID chip’s filter or envelope. aChChid does not use ChooChooTracker’s unified post-filter or ADSR.

Cutoff and Decay use logarithmic editing: EDIT + LEFT/RIGHT moves by one musical control step, while EDIT + UP/DOWN moves by sixteen steps. Cutoff covers 200 Hz to 20 kHz; Decay covers 200 ms to 2 s.

An F in the note volume column triggers an accent. Normal notes use a half-step gate (3 ticks in the default 6-tick groove). ASL slides to that note from the previous pitch without retriggering the 303 envelope; it automatically holds the preceding gate, and ASL 00 gives a 60 ms glide. ATY keeps its note open for the whole current step. Notes without ASL always retrigger. Modulation destinations include Decay and Accent, plus Timbre and Color in Braids wave mode.

Bogie

Bogie is a native one-shot drum synthesiser. Tracker notes set pitch and the tracker/instrument volume sets level; each trigger has its own internal decay, so it has no ADSR page. It has 12 models: Kick, Snare, Hat, Clap, Tom, Rim, FM, Noise, Cowbell, Cymbal, Shaker and Clave.

Its six macros are Decay, Tone, Sweep, Noise, FM and Drive. Their labels adapt where useful (for example, Kick’s Noise is Click, and Cowbell’s FM is metallic cross-modulation). Every macro is active on every model, but its musical role changes with the model: Sweep can alter pitch, burst spacing or metallic spread; FM can add cross-modulation, a metallic layer or a ring-like overtone. The lower half of each range is intended for conventional drum sounds; the upper half deliberately opens wider timbral morphs and more synthetic results.

Every model can use the shared LP/BP/HP multimode filter, with Clean, Classic, Aggro, Acid, Roar or Snarl character, cutoff and resonance. Clean, Classic, Aggro and Acid expose 12/24 dB slope; Roar and Snarl expose Color instead. Bogie supports all of its active macros plus Volume, Pitch, Cutoff and Resonance as modulation and motion-recording destinations. Use short Decay with Cowbell for sharp phonk attacks; increase FM for a harder, more metallic bell.

On the Modulation screen, press EDIT on a source to choose a family (Envelopes, LFO or Sticks), then its source. Left and Right still cycle sources directly.

Sintered

Sintered is a native one-shot digital percussion synth. Notes set its fundamental pitch; its six models are Knot, Shard, Burst, Comb, Logic and Melt. Every model has Decay, Mod and Motion, plus three model-specific controls: Knot uses Ratio/Spread/Fold, Shard Ratio/Feedback/Bite, Burst Noise/Color/Feedback, Comb Time/Damping/Regen, Logic Rate/Pattern/Crush and Melt Ratio/Chaos/Drive. Mod is always the internal coupling depth.

Motion is an internal macro envelope, not pitch glide: values below 80 use an AD shape, 80 disables it, and values above 80 use a decay-only shape. Moving farther from the centre makes the envelope faster. Its destinations are fixed per model, so Sintered stays predictable in tracker patterns: Knot animates Mod/Fold; Shard Feedback/Bite; Burst Noise/Color/Feedback; Comb Damping/Regen; Logic Rate/Crush; Melt Chaos/Drive. All models reset their state on a note trigger and bound internal feedback for repeatable hits.

MonkSynth

MonkSynth is a vocal synthesiser. Shape its vowel, voice character, breath, glide, vibrato, unison and delay from the Instrument page. EDIT opens every control and the patch name.

Choose a bank and preset above the VOICE controls. ALL includes FACTORY and USER; EDIT+PLAY auditions the highlighted preset, while EDIT selects it. Save your own sounds under instruments/USER/monk/. Saved instruments and songs retain their MonkSynth settings.

Values use hexadecimal 00..FF, except Voices (01..0A, one to ten). Attack, decay and release span 0..5 seconds; detune spans 0..50 cents and voice spread 0..0.5. Volume, Pitch and the six main voice controls are available as modulation and motion-recording destinations.

All sixteen controls appear together under MonkSynth FX: MWV (vowel), MIN (voice), MAM (breath), MFL (glide), MFB (vibrato depth), MSH (vibrato rate), MUV (voices), MDT (detune), MVS (spread), MDM (delay mix), MDR (delay rate), MLV (level), and EAT/EDC/ESU/ERL (ADSR). These voice meanings apply when MONK is the active instrument; the existing MME command meanings remain unchanged. The shared Trigger FX group retains TDC/TCL without duplicate envelope entries.

MME

Choose SYNTH → MME from the Instrument Type menu.

MME (Multi Modulation Engine) is a two-oscillator synth dedicated to interactions between oscillators. Its models are Ring, Fold, Cross, VPM, Sync, Logic and Vocode. Both oscillators are internal and follow tracker notes; Interval sets their relationship.

The six macros are Waves, Interval, Amount, Flow, Feedback and Shaper. Waves selects musical A/B waveform pairs. Amount controls the model’s core interaction, Flow changes its direction or algorithm variant, and Feedback is bounded but becomes deliberately wild at the end of its range. Shaper is a shared final stage which moves from clean through saturation to wavefolding.

MME uses the shared LP/BP/HP multimode filter and ADSR. All six macros, Cutoff and Resonance are available to modulation and motion recording. Hold EDIT on Model to open the model popup.

Audio in

Choose External > Audio in to process a live stereo input on a track. On SOURCE, choose External or one of the eight internal tracks. An internal source taps that track after its inserts and reroutes it to Audio in, so the source is no longer sent directly to the mixer. The resulting sound follows Audio in’s notes, filter and envelope, then the destination track’s inserts and mixer settings. Select Device > [Open] to open the audio input settings and arm an external source; Back returns to the instrument. You can also reach these settings through Settings > Audio > Audio Input. Then enter notes in a phrase using this instrument. Any note opens the ADSR; note-off starts its release. The note pitch does not transpose the incoming audio. Without a note, the input stays silent on this track.

The Input level meter shows the selected source before Audio in’s envelope and filter, including while no note is playing. For an internal source, this includes the source track’s inserts. The track waveform shows Audio in’s signal during playback.

The stereo input passes through the instrument’s FILTER and ADSR, then the track’s inserts, volume, pan and effect sends. The filter and envelope controls work like those on the Sampler. Leave the Sampler’s dry input MON off if you only want to hear the processed signal.

The Sampler can record an input while Audio in processes it. Select the Audio in track as the Sampler’s track source to record its processed output, including its track inserts. Offline song export has no live input: record or bounce the performance into a sample first. Audio in uses the active capture device, shared by the armed inputs.

MIDI Out

MIDI Out (desktop only) drives an external MIDI device instead of synthesizing audio: triggering a note sends a real MIDI Note On on the instrument’s Channel (1-16) and, when the note ends, the matching Note Off. Volume becomes velocity, and a chord track’s voices each get their own Note On/Off. There is no audio to hear from ChooChooTracker itself - select the output device under Settings first. See MIDI for the full picture, including sound preview from a MIDI keyboard.

Program and Bank high/low (CC0/CC32) are optional - shown as -- when off, Clear toggles a field off and remembers its value. When set, they are sent once, right before the next note, whenever they differ from what that channel was last told (not before every note, which would retrigger the receiving device’s own envelopes/patch).

MC1 number-MC4 number pick which CC number (00-7F) each of the four MC1-MC4 row FX sends to - see MIDI Out FX. Also --/optional; a slot left unset makes its FX inert.

Subtractive engines

The engines in this category share a VCO to VCF to VCA architecture.

Several VCO types are available:

• Braids
• Plaits
• Plaits-Alt
• Sampler
• 2xSCWF
• BYOWTBL

Each instrument feeds its VCO into a multimode filter.

The filter can work as a low-pass (LP), band-pass (BP) or high-pass (HP) filter, with cutoff from 20 Hz to 20 kHz. Clean, Classic, Aggro and Acid have a 12 dB/24 dB slope switch. Roar and Snarl use Color instead and have an 18 dB LP/HP base slope; their BP upper slope is steeper than the lower slope. Snarl’s saturation can add harmonics above the cutoff.

Several filter characters are available:

• Clean: sterile and digital
• Classic: inspired by classic American analogue synths
• Aggro: gritty MS-20-style KORG-35 filter, with resonant LP, BP and HP
• Acid: Open303’s TB-303 low-pass in LP/24; its other modes and slopes are Open303-based adaptations. In LP mode, notes keep more bass as resonance rises. Acid reaches an effective maximum cutoff of 12 kHz (slightly lower below a 48 kHz output rate), even though the shared cutoff control reaches 20 kHz.
• Roar: inspired by Massive’s Scream filter; a saturated filter with a separate high-pass feedback path. Color increases its growl and drive.
• Snarl: inspired by Bitwig’s Rasp; a short saturated delay loop creates moving resonant teeth around the cutoff. Color changes their spacing and intensity.

For Roar and Snarl, Color runs from 00 (0%) through 80 (150%) to FF (300%). The upper half intensifies Roar’s saturation and Snarl’s moving peaks. Older projects that selected Prism play that character as Snarl, retaining its Color value.

Aggro, Acid and the creative characters can get strongly resonant. Start low and turn them up gently. Existing Aggro and Acid instruments use these new sounds when loaded.

The filter feeds a VCA controlled by an ADSR envelope. The envelope shape can morph between exponential, linear and logarithmic curves.

Plaits and Plaits-Alt

Plaits provides 24 engines, grouped in the selection popup as follows:

Plaits-Alt is a collection of alternative models for the original Plaits module. Most are stranger or more experimental than the average VCO.

The parameters follow Mutable’s design:

• Harmonic controls harmonic relationships, balance or model choice inside an engine.
• Timbre generally moves from dark/sparse to bright/dense spectra.
• Morph explores another timbral dimension.
• Main/Aux blends the main output with the engine’s alternate output.

Their precise meaning depends on the engine. For example, chord engines use them for chord type, inversion and waveform. Physical models use them for material, excitation and decay, while drum engines use them for tone, character and decay. Refer to the Plaits user manual for details.

For CHORD, DIATONIC CHORD and WT DIATONIC CHORD, Harmonic displays the selected chord name (MIN, MAJ, MIN7, MAJ7, and so on) rather than its raw control value. Braids WAVE PARA similarly names its Color voicings.

Tap Engine to choose from categorised engine lists.

Env Mode has 2 routings:

• TRIG reproduces the module with TRIG connected and LEVEL unpatched
• VCA holds LEVEL open and applies the tracker ADSR after the voice

Sampler

This clean Sample engine plays mono or stereo PCM samples loaded into RAM.

• Tap Sample to load an uncompressed 8-bit, 16-bit or 24-bit PCM WAV. Press PLAY in the browser to audition the highlighted file.
• When a sample is loaded, EDIT appears next to its name. Tap it to open the Sample Edit screen. OPT or SELECT + [LEFT] returns to the instrument.
• The Sample Edit screen shows the filename (with a * marker when the sample in RAM differs from the file on disk), a format readout (sample rate, channels), a tall waveform, and the Region, Select, Loop, Slice, Process and File fields.
• Processing edits start in RAM. Project saves and autosaves embed the current sample audio in the .cct; Save/Save As in Sample Edit writes the separate WAV. The * marker means the sample in RAM differs from that WAV. Loading another sample replaces the current audio in RAM and resets the Region to the full sample (Start 00, End FF).
• Region sets the playback Start/End markers, also available on the Sampler instrument screen. They set normalised playback boundaries (00-FF); if Start is after End, the sample plays in reverse. EDIT + [LEFT/RIGHT] fine-adjusts the marker in steps of one (01) and zooms the waveform around it while EDIT is held; EDIT + [UP/DOWN] coarse-adjusts (step 16) and returns the view to the full sample. EDIT + OPT resets the marker to its default (Start 00, End FF).
• The waveform view zooms to a fixed window of 5/7 of a second of audio (40% more magnification than a full second) around the edited marker and pans to keep it visible; samples that fit inside the window stay at the full 1:1 view. The zoom is transient: it lasts while EDIT is held, and releasing EDIT returns to the full 1:1 view, as do coarse steps. Entering the screen always resets the view to the full sample.
• Loop is a row with two cells: START (loop start) and SPD ALGO (speed algorithm). It sits between Select and Slice on screen.
• START shows the loop wrap point in hex and is always adjustable; when looping is off, the marker is ignored in playback. The red waveform marker appears only while looping is active and the value is nonzero. EDIT + [LEFT/RIGHT] fine-adjusts the marker in steps of one (01) and zooms the waveform around it while EDIT is held; EDIT + [UP/DOWN] coarse-adjusts (step 16) and returns the view to the full sample. EDIT + OPT snaps the marker to the Region Start. The wrap point is drawn as a red marker on the waveform and clamps to the Region: it can never sit before the Region Start or at/after the Region End. Editing the Region markers moves the wrap point back to the Region Start whenever it would fall outside the new Region. Projects saved before this feature load with the wrap point at the Region Start (no audible change).
• SPD ALGO picks the time-stretch algorithm used when Speed differs from 100%: Granular (default) or Stretch. The box shows - when the mode is OFF.
• Select sets a processing selection in absolute frames, independent of the playback Start/End markers. EDIT + [LEFT/RIGHT] moves a handle fourteen frames and zooms onto it while EDIT is held; EDIT + [UP/DOWN] jumps by frameCount/64 (minimum 16) and returns to the full-sample view. EDIT (tap) on a handle copies the current Start or End marker position to it. EDIT + OPT on either handle empties the whole selection. When the selection is empty both handles show -; when the handles are inverted they swap automatically. The selection is session-only editor state: it is not saved with the project, and entering the screen seeds it with the playback Region span (the whole sample with the default markers).
• Slice is a single row with four value cells - Mode, Count, Slice and Frame - and is saved with the instrument. Off plays the Start/End window. Phrase notes select slices chromatically from C-0, and notes past the last slice wrap around to the beginning (note N plays slice N % count, so a run past the last slice cycles back to the first one). Sliced notes do not transpose pitch or use Scale quantization, but CRD keeps the selected slice and transposes its voices as a chord. Slice starts are marked on the waveform with short two-pixel-wide lines (dark orange; the current slice’s line is brighter), and the slice under the cursor gets a black background band on the waveform (the selection tint is not drawn over the band, so it stays fully black and clearly distinct from the rest of the preview).
  • Mode cycles OFF / EQUAL / AUTO / LAZY (EDIT + left/right or tap; EDIT + OPT turns slicing off). Switching modes initializes the slice points: EQUAL divides the Start/End window evenly into Count parts; AUTO runs a transient detection over the window and places a slice on every onset it finds (up to Count); LAZY starts with one slice covering the whole window. Switching to LAZY stashes the current EQUAL/AUTO setting (count and bounds), and switching back to EQUAL or AUTO restores it verbatim - no confirmation is asked and nothing is lost. Slice and Stretch are mutually exclusive: enabling one disables the other, and the Slice cells are dimmed while Stretch drives the duration.
  • Count shows the total number of slices (01..64). EDIT + [LEFT/RIGHT] steps it by one (minimum 1, maximum 64), EDIT + [UP/DOWN] cycles through the power-of-two counts 2 / 4 / 8 / 16 / 32 / 64 with wrap-around. Every change recalculates the division: EQUAL re-divides the window evenly, AUTO re-runs detection with the new target (the detection sensitivity is derived from the count - more slices mean a more sensitive threshold). The box shows - when the mode is OFF. In LAZY it stays bright (it counts the hand-placed slices) but is display-only: the cursor skips it — moving right from Mode or left from Slice lands on Slice, coming down from the Select row’s END marker lands there too, and touching the box does nothing (hand-placed slices have no division to recalculate). EDIT + OPT and a plain EDIT tap do nothing here: turning slicing off lives on Mode, deleting a slice lives on Slice.
  • Slice is the browser: it shows the 1-indexed current slice (01..count). EDIT + [LEFT/RIGHT] moves between slices one at a time, EDIT + [UP/DOWN] jumps four slices (both clamped, no wrap-around); the browsed slice is indicated on the waveform by its brighter marker and the black band, and the zoomed view recenters on the slice start. EDIT + OPT deletes the current slice (it merges into the previous one; the first slice cannot be deleted, and deleting the last remaining slice turns slicing off - bounds survive an OFF round-trip and come back when a mode is picked again). EDIT (tap) previews the currently selected slice as a one-shot playback (works in every slice mode; the preview stops when the key is released or when you leave the screen). The box shows - when the mode is OFF.
  • Frame shows the current slice’s start frame in hex. EDIT + [LEFT/RIGHT] nudges it by seven frames (zooming onto the marker while EDIT is held), EDIT + [UP/DOWN] nudges by one hundred and returns to the full view. A marker stays inside its own slice: it cannot cross the previous or next slice start. EDIT + OPT deletes the slice.
  • B exits to the instrument screen from the Slice row like everywhere else on this screen; SHIFT + LEFT exits from anywhere.
  • LAZY workflow: with LAZY selected, tap PLAY to start a one-shot full-sample playback - it plays once from the start and stops by itself at the sample’s original pitch and speed (a green two-pixel marker follows the position on the waveform); tapping PLAY again stops it early. While it plays, every EDIT click drops a slice at the playback position, no matter where the cursor is (slices closer than 50 ms to an existing one are rejected with Too close to slice). Playing the sample again keeps the existing chops and adds new ones at every tapped position, in order - the Count box refreshes with every dropped slice and the Slice browser follows the new one. The same browsing and editing rules as the other modes apply to hand-placed slices: EDIT + direction on Slice browses them, Frame adjusts the selected start, EDIT + OPT deletes the current slice. The Frame cell dims while the playback-drop is armed. SHIFT + PLAY is not intercepted in LAZY: it starts phrase playback like on every other screen. LAZY slices play back in the sequencer just like EQUAL and AUTO: phrase notes map chromatically from C-0 onto the hand-placed slices, wrapping around past the last one.
  • Combo hints: while the cursor rests on a Slice row cell and no other message is showing, the status bar shows that cell’s hint and keeps it up while the cursor rests there. On Mode the hint is bound to the active mode and shows only the description (the mode name is already in the cell): Divides sample in equal parts, Divides sample based on transients, Press Play and add slices with EDIT - switching modes swaps the text immediately, and OFF clears the bar. On Count it shows Adjust the number of slices, on Slice Browse slices, on Frame Adjust slice start. Any action message replaces the hint until it expires.
• Process selects a destructive editing operation: Crop, Normalize, Delete, Silence, Fade In, Fade Out or Reverse (EDIT + left/right cycles, tap cycles forward, EDIT + OPT sets none). GO (same row) runs the selected operation on the current selection, or on the whole sample when the selection is empty. Crop keeps only the selection; Normalize scales the selection so its peak reaches full scale (both channels share one gain so the stereo image is preserved); Delete removes the selection and joins the tails (deleting the whole sample is rejected); Silence zeroes it; Fade In/Fade Out ramp the selection linearly from/to silence; Reverse plays the selection backwards (frames are swapped in place, both channels of a frame move together, length and markers are unchanged). Crop and Delete require a selection — with an empty selection they show Select region first. Every operation pauses audio briefly, keeps a one-level undo, and marks the sample as changed in RAM: the file on disk is not touched until the Save flows (see below), and leaving the screen discards the undo slot.
• UNDO (next to GO) swaps the sample back with the state before the last operation. It is dimmed until an operation runs, toggles between the pre-op and post-op states on repeated presses, and is cleared when the screen is re-entered.
• File holds the save flows. The instrument stores the full path of the WAV it was loaded from; these flows write that file or point the instrument at a new one. They never touch the instrument name.
  • The File field cycles between Save and Save As (EDIT + left/right or tap); GO (same row) runs the shown action.
  • Save overwrites the WAV the sample was loaded from. For a sample without slices it asks Overwrite <name>? first. A sliced sample first opens the SAVE SLICES dialog asking where the slice points belong: SAVE TO SAMPLE writes them into the WAV as cue chunks (portable - DAWs show them as markers) and keeps them in the project too, SAVE TO PROJECT writes a plain WAV and keeps the points in the project only, CANCEL aborts. A Don't ask again in this project checkbox stores the picked destination with the project and skips the dialog from then on (the choice is saved as - Sample save choice: in the .cct and can only be changed by editing the project file). The dialog is skipped for samples without slices. Save is dimmed (and skipped in navigation) until a sample with a file path is loaded. A failed write keeps the dirty marker and shows the error.
  • Save As writes the current sample to a new file: enter a file name (pre-filled with the current name without extension), then pick a folder in the browser. The sample is written as <folder>/<name>.wav, the instrument points at the new file, and the folder is remembered as the default sample folder. It is dimmed (and skipped in navigation) until sample data is loaded, so a freshly loaded sample can be given a file path. Paths longer than 255 characters are rejected.
  • The * marker before the filename means the sample in RAM differs from the file on disk (any process operation sets it, Save and Save As clear it). The marker is session-only: it is not saved with the project and resets when the screen is re-entered. If several instruments reference the same WAV file, saving one overwrites the file for all of them.
• On the Sample instrument screen, use EDIT + [LEFT/RIGHT] to load the previous or next WAV in the same folder.
• Pitch transposes by semitones (-48 to +48).
• Loop selects Off, Loop, Ping-Pong, Loop X-Fade or Ping-Pong X-Fade. The X-Fade modes crossfade the loop wrap over the last 25% of the loop window instead of hard-cutting it.
• Speed controls time-stretching from 0% to 500% (100% is normal); the algorithm (Granular or Stretch) is picked on the Sample Edit screen’s SPD ALGO cell.

Unsupported WAV formats display an error. Convert unusual files to PCM8, PCM16 or PCM24 WAV before importing them.

Audio input

Open Settings → Audio → Audio Input before recording from a microphone or USB audio interface. The list shows the inputs currently available to the device. If an armed interface is disconnected, capture is interrupted and the audio handler restarts so the app can continue running. If you were recording, press STOP to finish the interrupted take. After reconnecting, select [Refresh] and check that the intended input is armed before recording again; reconnecting alone does not reliably re-arm it. [List] re-reads the current input list without restarting audio. To turn an input off, select its [x] box in that list and press EDIT. To turn all inputs off at once, press CLEAR on the Audio Input row in Settings → Audio.

Select an input’s ARM box to make it available to the Sampler recorder; its small meter shows the incoming level. Arm one interface at a time: this version opens only the first armed interface, even if several boxes are checked. Your selection is remembered by device name, so an unavailable interface stays unarmed rather than being replaced by another input. Press OPT to return to Audio settings.

Recording audio input

On the Sample instrument screen, REC (or EDIT/REC when a sample is loaded) opens the sample editor, which hosts recording and editing in one screen. Arm inputs on the Settings → Audio → Audio Input screen first (see Audio input). The editor’s top rows control recording:

• Input cycles the recording source: T1..T8 record the tracker’s own eight tracks, followed by the armed microphone or USB interface. For external recording, keep cycling past T8 until the device name appears. - means no source was chosen explicitly; REC then uses the first armed input and shows its name. Hold EDIT and press LEFT/RIGHT to step backwards/forwards, or EDIT+OPT to clear to -. Tapping Input cycles it directly.
• The level meter next to Input shows the armed input’s live level (external sources only). MON toggles input monitoring: the armed input is routed to the output at -6 dB to reduce feedback. The setting is saved in the settings file.
• REC starts recording. External sources record immediately; a track source shows ARMED and recording starts when playback starts (press PLAY). STOP finishes the recording: the WAV is written to the project’s export folder (recNNN.wav), loaded into the current Sampler instrument, and the Region resets to the full sample. Leaving the screen with OPT while a recording is in flight finalizes it the same way.
• PLAY (shown after a recording) auditions the take; it becomes STOP while the preview plays. CLEAR (next to it) deletes the WAV file and unloads the sample from the instrument; after clearing, REC takes its place again.
• The waveform shows the live input while recording and the full recorded waveform after the recording stops. The status line shows the file name while recording and the frame count after; an external take also shows drop 0 when no audio frames were lost. A recorded sample is fully editable: loop region, selection, slicing, processing and saving all work on it like on any loaded file.

Recordings are written at the selected audio sample rate as stereo 16-bit WAV files. Track sources capture what the track’s instruments render (post-FX); external sources capture the device input directly.

2xSCWF

2xSCWF is a dual single-cycle waveform oscillator. Load 1 mono WAV containing exactly 1 period into each oscillator. Both oscillators read forwards and wrap at the end of their cycle.

Mix crossfades A and B.

Detune is fine and exponential from unison through +200 ct, then moves in semitone steps from +3 st to +24 st.

2xSCWF treats each file as a 1-cycle table and reads it exactly once per oscillator cycle. This lets you blend and detune 2 single-cycle waves.

The factory waveforms/AKWF/ folder contains waveforms from the Adventure Kid library. Plenty more are available online if you want to expand the collection.

BYOWTBL

BYOWTBL is a dual wavetable oscillator compatible with Serum tables. Each oscillator loads a mono WAV containing consecutive single-cycle frames. Pos A and Pos B scan their tables independently from 00 to FF. The engine interpolates linearly within each frame and between adjacent frames. Mix crossfades the oscillators, and Detune offsets oscillator B.

6. Modulation and motion recording

Each instrument can have up to 4 modulation slots. Audio instruments can target Instrument Pan or Track Pan; both use 00 for left, 80 for centre and FF for right.

The available modulation types are:

• ADSR - classic attack-decay-sustain-release envelope
• AHD - attack-hold-decay envelope
• LFO - low-frequency oscillator with several shapes
• syncLFO (formerly SLFO) - LFO with a ticks-per-unit setting and period multiplier
• slowLFO - long cycles with an evenly proportional period control, starting just beyond the ordinary LFO range
• FLFO - audio-rate LFO that can reach the kHz range; FLFO can be heavy on the CPU
• SLIN - linear joystick control
• SRAT - rate-based joystick control
• Sequence - reads the tracker sequence as a modulation signal: PITCH is the final sequenced pitch, VOL is the final sequenced volume, and TRANCE GATE is an independent rhythmic modulator. Its Motif, Rate and Length select the gate pattern; Trigger chooses whether it is free-running, retriggered per note, or restarted at Phrase or Chain boundaries. Closed gates output zero, open gates output half level, and Accents distributes full-level gates euclidically across the active gates. It does not use or change a track insert.

The list of modulation destinations depends on the instrument type.

For a Cutoff destination, Amount is exponential with a quadratic response: 25% reaches 4.5 semitones, 50% reaches 18 semitones, 75% reaches 40.5 semitones, and 100% reaches six octaves. This keeps fine control at low amounts while still allowing deep sweeps.

When an ADSR or AHD envelope targets Volume, it becomes the instrument’s volume envelope. An LFO targeting Volume offsets the current output volume instead.

The modulation amount can be positive or negative. Its range depends on the destination. If the destination’s full range is 127 or less, as it is for most parameters, the amount defines an absolute range. Wider destinations such as pitch use a scaled amount.

PITCH and VOL Sequence sources have a Mode. Normal keeps the tracker value audible while also using it as modulation. Bypass makes it a source only: PITCH retriggers at the last pitch (or C-4 for the first note), and VOL keeps the last audible level. Trance Gate is already source-only. If any active Sequence slot bypasses PITCH or VOL, bypass wins. To prevent feedback, PITCH and VOL cannot target Pitch or Volume.

All duration parameters, including attack, hold, decay and period, are measured in ticks.

syncLFO is the former SLFO: set its ticks and multiplier for tempo-synced movement. Existing SLFO settings and songs keep the same timing.

Use slowLFO for sweeps longer than the ordinary LFO can make. Its Period control runs from 256 to 131,072 ticks. All tick-based LFOs follow song tempo and share the same shapes, wavetable selection and trigger modes. Choose Free for a sweep that continues across notes; Retrig, Phrase and Chain restart it at their respective boundaries.

LFO shapes:

• Tri - bipolar triangle wave
• Sin - bipolar sine wave
• UniTri - unipolar triangle wave
• UniSin - unipolar sine wave
• RampDn - linear ramp down (saw wave)
• RampUp - linear ramp up (saw wave)
• ExpDn - exponential ramp down (exponential saw wave)
• ExpUp - exponential ramp up (exponential saw wave)
• Square - square wave
• Random - sample-and-hold random wave
• Wavetable - reads one of the project’s 32-step AY wavetables. Values 00 to 0F map from -100% to +100% without interpolation.

LFO trigger types:

• Free - restarts the LFO only when the instrument changes
• Retrig - restarts the LFO on every note
• Phrase - restarts LFO, syncLFO and slowLFO when playback enters a new phrase
• Chain - restarts LFO, syncLFO and slowLFO when playback enters a new chain
• Hold - stops after 1 cycle and holds the last value
• Once - stops after 1 cycle and returns to zero

Motion recording

• STICK LIVE (L1 by default) applies stick modulation without changing the phrase. In Settings > Stick live mode, HOLD (the default) enables it while held; TOGGLE enables it on one press and disables it on the next; FREE leaves it permanently enabled. Releasing the button in TOGGLE leaves it enabled.
• During playback, hold MOTION RECORD (L2) to apply stick modulation and record changed destinations as absolute FX values.
• Hold MOTION ERASE (R2) to remove matching destination FX from the current row.

The bottom-right ~ indicates active Stick live. Record (*, or ! for overflow) and Erase (x) take indicator priority and remain momentary in both modes. Both enable live stick processing while held; releasing them leaves a separately enabled live toggle intact.

The mode is saved with application settings, but the live toggle always starts off on launch. Changing modes clears the toggle: HOLD follows any currently held Stick live button, TOGGLE waits for a fresh press, and FREE is active immediately.

Motion recording writes track FX into the phrase currently playing. It updates matching FX first, then uses empty slots from right to left. It never overwrites a different FX. If all 3 slots are full, that motion is not recorded on the step. A ! in the bottom-right corner means that more destinations changed than the 3 FX columns could hold.

Motion recording supports Braids, Plaits, Sampler, 2xSCWF, BYOWTBL and Bogie destinations, including active Bogie macros and filter controls where applicable.

7. Tables

Tables are a core sound design tool in trackers. In Vortex Tracker terms, they combine instruments and ornaments, but they can do much more. If you know LSDj or NerdSEQ, the idea should already feel familiar.

The Pitch column accepts relative (~) or absolute (=) pitch values in semitones. The Volume column is 00-7F, applies to every engine on top of its envelope, and can be used for a gate: alternate 7F and 00 then loop with HOP 00. The 4 FX lanes mostly match the lanes in a phrase, although a few FX behave differently in tables.

Putting a TIC FX on the last table row sets the speed of that column and overrides the instrument’s default table speed. Each FX column can run at a different tick speed. The Pitch and Volume columns follow the speed of the 1st FX column.

A 16-row table may look short next to a long Vortex Tracker instrument, but the HOP FX can create conditional loops such as “repeat these rows 5 times”, as well as nested loops. With loops and independent FX column speeds, those 16 rows can go a surprisingly long way.

Retrigger mode

The Retrig field at the top of the Table screen selects when an already active table restarts. Inst is the default and compatible mode: a phrase row containing an instrument selects that instrument’s default table and starts it at row 00. Phrase restarts an active table when playback enters a phrase, Chain when it enters a chain, and Free leaves it running until the track stops or an explicit command replaces it.

A structural mode never reaches backward in time. If a track has no active instrument table, the first phrase row that introduces an instrument activates its table at that exact row, even if it is row 4, 8 or F of a phrase. Later instrument numbers do not replace an active Phrase, Chain or Free table. This makes tables useful as LFO-like automation without silently simulating earlier phrase steps.

TBL, TBX and RET are always explicit actions: they select or restart immediately, whatever the mode. On a Phrase or Chain boundary, its restart happens before the new phrase row is read, so a TBL or TBX on that row has the final say. Table row 00 FX therefore run again normally; cumulative FX retain their usual accumulation.

Tables 00-7F are reserved for default instrument tables. Tables 80-FE are intended for auxiliary tables started by the TBX effect. The lower range also works for auxiliary tables, but using it that way can cause unexpected conflicts and confusion.

Copy FX between Phrase and Table

Select only FX name/value columns, then copy or cut them from a Phrase and paste them into any FX lane of a Table, or do the reverse. The copy keeps the exact selected cells, so a command-only or value-only selection remains partial. Pasting begins at the current FX cell and is clipped at row F and the destination’s final FX lane. Notes, instrument numbers, pitch and volume never cross between these two screens.

Controls

• EDIT + [UP/DOWN] on an FX name column: open the FX selection screen
• OPT + [DIRECTION]: move between tables

8. Other screens

Instrument Pool

The Instrument Pool shows every instrument in the project and lets you reorder them. During playback, it also shows which instruments are currently active.

Controls

• EDIT: edit the instrument and jump to the Instrument screen
• SHIFT + OPT: copy the instrument
• SHIFT + EDIT: paste the instrument
• EDIT + [UP/DOWN]: reorder instruments
• EDIT + PLAY: preview the instrument

AY Wavetable

Wavetable is an AY Plus software oscillator type. A project can contain up to 256 wavetables, each with 32 steps. All wavetable instruments share the same set of waves. This screen is where you edit them.

AY volume levels are non-linear, so the Standard view waveform is drawn to match the actual output levels. Double-tap OPT to switch between the Standard view and the persisted LFO view, using the same shortcut as Song/Live Mode: the LFO view draws the raw 0–15 steps linearly, with the centre line between 7 and 8 as the modulation zero point.

The screen has 2 logical rows. The top row contains the Load and Save buttons, while the 2nd contains the wavetable editor.

Controls

• OPT + [LEFT/RIGHT]: move through the wavetable list
• OPT + [UP/DOWN]: move through the list by 16 waves
• SHIFT + OPT: copy the wavetable
• SHIFT + EDIT: paste the wavetable
• OPT + PLAY: switch between Standard and LFO view

9. Tracker FX

Track FX force sequencer or sound-engine values on individual steps. Other grooveboxes often call these “parameter locks”. Each Phrase row has 3 FX slots.

Each FX has a 3-letter command and a hexadecimal value. The in-app help panel gives a short description of the selected command.

Scale automation

SCL XY changes the global playback scale and root without changing the notes stored in phrases. X selects a scale (0 Chromatic, 1 Major, 2 Minor, through C Custom); Y selects the root (0 C through B B). The command applies to phrase FX only, not tables. If several tracks issue SCL on the same tick, the lowest-numbered track wins.

SCL belongs to Quantizer mode. With Note Lock active the command is not offered in the FX list, and any SCL already written into phrases is ignored while the mode is on.

Chords

CRD XY turns the note on its own Phrase row into a chord. Y selects: 0 Major, 1 Minor, 2 Dim, 3 Aug, 4 Sus2, 5 Sus4, 6 Power, 7 Maj7, 8 Min7, 9 Dom7, A Min7b5, B Dim7, C Add9, D MinAdd9, E Maj9, or F Min9. X selects one of 16 voicings: 0-3 are a rising closed inversion cycle; 4-7 add drop-2; 8-B add drop-3; and C-F combine both drops. The cycle continues through an extra octave for triads and power chords, so every value is distinct; larger values become progressively wider and less conventional. For example, CRD 4Y is drop-2 root position and CRD DY is first inversion with both drops. At the bottom or top of the pitch table, voices are clamped to its range. The command is not persistent: write it on every chorded row. Each generated note is quantized independently when Scale is active, in both Quantizer and Note Lock modes. It is available to software engines only; AY instruments ignore it and remain monophonic.

Sequencer FX

Audio FX sends

Like a mixer send, RSN and DSN only change how much new sound goes into the effect. Sound that is already in the reverb or delay keeps ringing out after the next note, even when nothing else sends to the effect.

ADSR / Trigger FX

Conditions

Inspired by Swedish “trig conditions”, the tracker supports trigger probabilities and modulo conditions.

MOD counters are local to the track and phrase. Invalid combinations, such as A greater than B, do not trigger.

MOD34 triggers on the 3rd pass of every 4-pass cycle. MOD1F triggers on the 1st pass of every 16-pass cycle.

Playback speed

Like NerdSEQ, ChooChooTracker supports an independent playback speed for each track.

SPD reads its value as a signed byte. 00 is normal speed, positive values make the track faster, and negative values make it slower. The setting remains active until another SPD command changes it.

Older projects without signed SPD support keep their original 00-10 mapping, so they still play as saved.

Very high multipliers can exceed the resolution of the tracker tick scheduler and have not been hardware-tested.

Modulation FX

Phrase and table FX can change a modulation slot without editing the instrument:

The value is interpreted as a signed 8-bit relative change (01 adds 1, FF subtracts 1). Repeated commands accumulate. Effective values are clamped to their valid range.

P5 is not exposed as a phrase or table FX. It is available as the M1–M4 Wavetable modulation destination, so one modulator can scan the AYWavetable index of another.

Braids FX

aChChid FX

Bogie FX

Sintered FX

MIDI Out FX

Plaits FX

Sample FX

AY FX shared by AY instruments

AY Classic-only FX

AY Plus FX

AY Sample FX

AY Sample accepts the shared AY commands plus TNN, TNP, TNF, TRT, SFN, SFP and SFF as described above.

Engine parameter FX apply to their matching instrument type and are reset at the next note trigger unless stated otherwise. SPD is intentionally persistent.

The FX selector filters this reference to common commands plus the group supported by the active instrument. The contextual help panel provides value details while editing.

10. Mixer, Reverb and Delay

The Mixer is the leftmost main screen. It displays CPU load and clipping warnings. A red ! in the CLIP column marks the track whose dry signal pushed the mix beyond the safe range.

Use it to balance the 8 tracks, shape each track with Tilt EQ, and send audio to the reverb or delay:

The mixer is track-based, not instrument-based. If a track changes instruments, its level, PAN, Tilt and sends remain attached to the track. Instruments also have their own 00-FF Vol and Pan in the top row of the Instrument screen. Instrument PAN is applied first, then track PAN. Both preserve an existing stereo image at centre; they progressively attenuate the opposite side when moved left or right.

On the MASTER FX row, select LEVEL to adjust the overall output volume from 001% to 100%. This is the same Mix volume setting found in Settings > Mixer and is saved for the device, so it is useful on consoles without a physical volume control. Select EDIT to open the master effects.

During playback, the output limiter lowers sustained loud signals and isolated peaks, and removes DC offset. If a dense mix sounds quieter than expected, lower track levels or effect sends. Keep the console’s own volume moderate when testing new sounds.

Auto Mix

The Mixer contains an AUTO MIX button. It renders 6 seconds offline, balances track loudness, then checks 8 octave bands against a pink-noise profile and gently lowers tracks that crowd those bands. It proposes conservative level changes, leaves some peak headroom and starts a temporary preview. Apply keeps the proposed levels, while Cancel restores the previous 8 levels. It gives you a useful starting point, but you will probably still want to tweak the result.

Clouds Reverb

Use SELECT + [UP] from Mixer to open the reverb settings screen.

• Return: wet reverb level in the master mix.
• Time: decay/time control, 00-FF.
• Damping: high-frequency absorption, 00-FF.
• Filter: low-pass filter applied before the reverb.

This is the Clouds reverb section, not the complete Clouds granular processor.

Ping-pong Delay

Use SELECT + [DOWN] from Mixer to open Delay, then SELECT + [UP] to return. Reverb works in the opposite direction: SELECT + [UP] opens it and SELECT + [DOWN] returns to Mixer.

• Return: wet delay level.
• To Reverb: amount of the wet delay signal sent into the shared reverb, 0-100%.
• Ticks: delay time in tracker ticks (9 ticks = 1 beat by default).
• Feedback: cross-feedback amount, limited to 95%.
• Filter: low-pass filter in the delayed signal path.

The 1st repeat follows the stereo input. Later feedback crosses between the left and right channels.

11. Project screen

The Project screen provides Load, Save, New, Export, Manage, Pitch table and Scale commands, along with filename, title and author metadata.

Export location

Exports, stems and bounces are written to a per-project folder inside the app’s preexisting samples directory:

• Default: <app folder>/samples/Exports/<project name>/. While the project is unnamed, the folder is current-project.
• On the web build the default is /user/samples/Exports/<project name>/.
• On Android the samples folder is inside the active workspace (private, picked, or shared).

The Folder row on the EXPORT screen shows the active destination:

• Tap EDIT to pick a custom folder with the folder browser. The chosen folder is used exactly as selected (no project subfolder is added) and is remembered in settings.
• EDIT + OPT (clear) resets to the default location.

When a named project is saved under a new name, the default export folder is renamed to match, keeping previously exported files with the project. Renaming does not apply to a custom folder, and the folder is not renamed by autosave. If a folder with the target name already exists, both folders are kept. If the tracker lost track of the folder (for example after a restart), saving a named project renames the existing current-project folder instead. Instruments keep working after a rename: loaded sample paths that point into the renamed folder are updated automatically.

Load also accepts .mid/.midi files, imported as a new project: notes are grouped by MIDI channel (one channel per track, up to the track count), quantized to 4 rows per beat, and placed on a single default AY instrument - MIDI program numbers have no chiptune equivalent, so pick real instruments afterward. Only the file’s first tempo is used (one global tick rate, no per-section tempo changes). The Export screen’s MIDI row does the reverse: writes the current arrangement’s notes, volume and tempo/groove as a Standard MIDI File (one MIDI track per tracker track); MIDI Out instruments and other per-row FX beyond volume and the global groove have no MIDI equivalent and are not translated.

Load also accepts Dirtywave M8 songs (.m8s, firmware 2.x-4.x), imported as a new project: structure (song rows, chains with transpose, phrases), notes, velocities, instrument numbers, note-offs, tempo and name. Notes keep their real pitch (the M8’s C-6 is C-4 here). Each instrument used is imported under its M8 name: MACROSYN becomes Braids (same 47 models; timbre, color, filter, cutoff, resonance and pan carried over, cutoff curve approximate), SAMPLER becomes Sample (the .m8s only stores the WAV’s path on the M8 card: the file is searched under the .m8s folder, its parents and your sample folder; otherwise the instrument keeps the M8 path and stays silent; +24 semitones of Pitch, as the M8 plays two octaves lower), FMSYNTH becomes a Genesis FM (rough approximation), WAVSYNTH and HYPERSYNTH become aChChid, MIDI OUT becomes MIDI Out (channel, bank, program, first 4 CCs). Other types become a default AY instrument. FX and tables are ignored.

On desktop, the Export screen’s M8S row does the reverse, in a limited way: tap it and pick an existing .m8s as a template (remembered until you quit, EDIT + OPT forgets it). Its song, chains, phrases, tempo and title are replaced and everything else is kept, except that Braids instruments are written back as MacroSynth and Sample instruments as Sampler (path /Samples/<file name>: copy the WAV there on the M8 yourself), if the template has an instrument of that type to copy from. FX are not exported, and a song using phrase FF or above cannot be exported (the M8 has 255 phrases). The exported file has not been tested on a real M8 yet. See M8 songs for the details.

On desktop and Android, Load also accepts Furnace modules (.fur, tested with the demos of Furnace 0.5 to 0.6.8.3; the newer format 240 layout is read but untested), imported as a new project from the first subsong. At most 8 channels can be kept: by default the channels that have notes, those playing samples first and those of a chip the tracker has instruments for before the others. The notes, volumes (rescaled to 00-7F), note-offs, song order (one chain per order and channel, cut into 16-row phrases) and speed pattern (groove 0) are converted, with the effects 00xy (ARP), 04xy (PVB), 08xy (PAN), 0Fxx (GGR), ECxx (OFF) and EDxx (DEL). YM2612, YM2151, OPL2/OPL3 (2 and 4 operators) and SID instruments become the matching tracker instruments (SID instruments keep their volume, arpeggio, pulse width, waveform and cutoff macros; the filter mode and resonance macros keep only their first step, and relative or other macros are dropped; the SID effects 1E0y to 1E5y (attack, decay, sustain, release, ring modulation, sync) become one instrument variant per combination used, and macros follow the song tick rate), and Furnace samples are written as WAV files to <samples folder>/<module name>/ and loaded into Sample instruments. AY-3-8910 channels get a default AY instrument; SN76489 instruments become Sega PSG ones with their volume, arpeggio and noise-mode macros; Game Boy channels become Game Boy pulse and noise instruments with their envelope, duty and volume macros (the wave channel plays a pulse); NES channels become Game Boy pulse and noise instruments with their volume, arpeggio and duty macros (the triangle plays a 50% pulse, the DPCM channel gets a default noise instrument, and the noise pitch is approximate); SNES instruments become Sample instruments, from the sample (BRR samples are decoded) or, for waveform instruments, from one looped cycle of the waveform (its envelope, wave synthesizer and echo are not converted); other chips keep their notes with a default square instrument. Macros, wavetables, the other effects and the other chips’ patches are dropped, and a message tells how many conversion notes there are.

On desktop and Android, the Export screen’s FURNACE row writes the project as a Furnace module (.fur, format 157, readable by Furnace 0.6pre5 and 0.6.8.3), saved in the project folder (the folder the project was last loaded from or saved to) rather than the export folder, with a _001 style suffix when the name is taken. The export is lossy because the tracker picks the sound per instrument and Furnace per channel: each track goes to the chip that matches the instruments it plays most (YM2612, YM2151, OPL2, OPL3, SID, otherwise AY-3-8910), with a default patch where an instrument belongs to another engine. Notes, volumes, chain transposition, the groove 0 speeds and the effects ARP, PVB, PAN, OFF and DEL are kept; samples, the other engines (Braids, Plaits…), the other effects and the tables are not. Chains of different lengths are padded with empty rows. On OPL3, a 4-operator patch only sounds on the first channel of a Furnace channel pair, so the tracks that play one are placed on channels 1, 3, 5… and leave the next channel empty.

On desktop, key jazz lets you type the filename, title and author directly on the keyboard instead of using the on-screen virtual keyboard — see Key jazz.

Scale / Quantize

The Scale screen controls the global 12-TET scale engine. The Mode row selects between two modes:

• Quantizer (default): phrase entry remains chromatic; when enabled, notes are rounded downward immediately before reaching the sound engine, so changing root or scale reharmonizes a song without editing its phrases.
• Note Lock: notes typed into phrases are snapped to the nearest note of the scale as they are entered, so only scale notes can be written. Fresh entries and decreases snap down; EDIT + RIGHT / EDIT + UP raise the note to the next scale note above. Entry always follows the project scale on this screen: changing the root or scale immediately affects newly entered notes on the enabled tracks, while notes already stored stay untouched. SCL FX is unavailable in this mode and any SCL already written is ignored. Playback quantization of plain notes is bypassed (entry is already locked); chord quantization via CRD still applies.

With the cursor resting on Mode, the status bar shows a fixed description of the active mode: Quantizes notes on playback for Quantizer, Snaps sequencer to scale for Note Lock. Toggling the mode swaps the text immediately; any action message replaces it until it expires.

Both modes share the same root, scale, Custom note editing and track checkboxes. Each of the eight track checkboxes decides which tracks the mode applies to. The scale engine is bypassed for non-12-note pitch tables and for Sampler instruments whose Slice mode is EQUAL, AUTO or LAZY (their notes select slices chromatically from C-0); MIDI input is not part of this version.

• Linear pitch selects the pitch-table mode. Off is the default and the hardware-validated setting for correct AY, Braids and Plaits octave tracking.
• Sync selects Off (local tempo), MIDI (incoming MIDI clock and transport) or Link (shared network tempo). With MIDI selected, Tempo is read-only and shows the measured incoming tempo. With Link selected, Tempo remains editable: edits are shared with the other participants, and their edits update this field too. This setting applies to all projects.
• Sync out selects Off or MIDI. MIDI sends clock at the current tempo, including a shared Link tempo. Select the MIDI output device and optionally enable Send transport in Settings > MIDI. Output is suppressed while Sync is MIDI; the saved output preference is retained.
• Tempo sets the project tempo in whole BPM (3-500). Internally the tracker still stores its tick rate in Hz (tick rate = BPM x 0.4), so existing projects load and save unchanged; a project with a fractional tempo displays it rounded and snaps to a whole BPM on the first tempo edit. Coarse adjustment steps by 5 BPM, fine adjustment by 1 BPM; clearing resets to the default 125 BPM.
• ChooChooTracker saves projects as .cct. This format is not compatible with ChipNomad.

Use Save before changing instrument types or loading another project.

Ableton Link

Ableton Link shares tempo and beat phase between apps on the same local network (Wi-Fi or Ethernet). Two ChooChooTracker devices can connect directly without Ableton Live or a computer. Each participant can change the shared tempo; there is no fixed leader. Joining an existing session adopts its tempo.

1. In Project, select Sync: Link.
2. Press EDIT on [Connect]. The right-hand status shows Searching, then the number of peers. 0 peers means Link is enabled and waiting for another participant. The first device uses its current project tempo.
3. Edit Tempo on either device to update the shared session. Tempo stays visible at all times, within the tracker’s 3-500 BPM range.
4. Press PLAY in Song, Chain or Phrase to launch that playback mode on the session’s next four-beat boundary. Shift+PLAY launches the song on that boundary too; note and row previews remain immediate. When the first participant starts alone, its launch establishes the shared downbeat for later joiners. Transport: On also shares play/stop with participants that enable Link start/stop sync; Off keeps playback controls independent while retaining tempo and beat sync.
5. Press EDIT on [Disconnect], or choose another Sync mode, to leave.

Older CCT versions that receive Link tempo can follow tempo changes from this version. Their transport behavior remains the behavior implemented by that version.

For Link to MIDI, select Sync: Link, connect, and set Sync out: MIDI. Choose a MIDI Out device in Settings > MIDI and enable external MIDI sync on the receiving device. Enable Send transport there if the MIDI device should also start and stop with CCT. Clock is sent during sequencer playback.

During Link playback, CCT gently corrects its local tick rate once per four-beat bar to keep beat phase aligned without skipping tracker ticks. Grooves, SPD and DELAY remain relative to tempo. Song positions, patterns and mixer settings are not shared.

Platform availability: PortMaster (primary target), Windows, Linux, macOS and Android are supported. The Web build and Miyoo builds do not include Link.

Android note: a constant audible offset can remain on the built-in speaker even when tempo stays synchronized. The current output-latency estimate does not measure the complete Android audio path.

PortMaster note: on PortMaster devices the audio buffer is larger (512 frames at 48 kHz), so beat alignment is best-effort within roughly 10-15 ms rather than sample-accurate. Tempo sync itself is unaffected.

12. Settings

• Audio offers a Sample rate of 32 kHz, 44.1 kHz or 48 kHz (default), an adjustable Buffer size (32 to 2048 frames), and Audio Output. Select Default for the system output or choose a connected interface, such as a USB sound card; the sound switches immediately and the choice is saved. If the interface is unavailable when the app starts, sound uses the system output. If selecting it fails, the previous output is restored. Changing the sample rate stops playback and sample preview while the sound engines and any armed audio input reopen at the new rate. If a device rejects the new rate, the previous setting remains active. Choose 44.1 kHz when the sound card runs at 44.1 kHz, so that the system does not resample the output. A larger buffer gives the audio engine more time but increases latency (2048 frames is about 43 ms at 48 kHz); 32 kHz reduces processing work and limits the highest reproduced frequency to 16 kHz. The CPU load readout shows audio rendering cost.
• Repeat delay / speed tune held-button repeat.
• Stick live mode selects HOLD, TOGGLE, or FREE for the existing mapped Stick live button.
• MIDI opens the MIDI submenu: device selection and the MIDI In channel-to-instrument mapping.
• Synths contains AY Quality, Sample dithering, and global Braids BITS / DRFT / SIGN settings.
• Mixer contains Mix volume and the per-project 250-4000 Hz Tilt pivot (default 1 kHz) used by all Mixer Tilt controls.
• Graphics contains Edit color theme, Load font, Persistent waveform, Track visuals, Waveform FPS, Boot screen, Cursor, and the playback counter settings. Cursor draws the cursor as a Line under the field (the default) or as corner Brackets around it; the original RG35XX build always uses the line. In the color theme, Text Labels colors the names of settings, a little dimmer than their values; Named Values colors values that are words (Off, Classic, LFO) rather than numbers; and Value Bars colors the bars that show where a value sits in its range. Themes saved before these existed get Text Default dimmed towards the background for labels, Text Default for names and the cursor color for bars. Waveform FPS sets the refresh rate of the instrument scope and mixer visualizers from 01 to 60. Track visuals selects Detailed (the synth waveform and its overlays) or Audio waveform (the actual summed output of that track) independently for every track; audio waveform clears any prior ADSR overlay immediately when playback starts. ChipNomad fonts and themes should work.
• Key mapping customises the controls.
• Support report writes a small diagnostic text file with the app version, platform, audio settings and CPU load, playback/overflow state, and a compact project summary. It does not include sample data or project title/author text. On Android and Web it opens the normal export/download flow; desktop and handheld builds save support-report.txt in the app’s writable folder.
• Quit ChooChooTracker exits cleanly.

The playback counter sits above the track list on the right. Playback counter selects Bars (000:0 at the start, then bar count and quarters 1 to 4) or Time (00:00). Rows per bar defaults to 16 and Ticks per row to 6, so a bar is 96 elapsed playback ticks regardless of the project’s groove. Both values can be changed in Graphics. The count continues across song loops, keeps its last value after stopping, and resets when playback starts again. Time uses the audio clock, including changes in tempo.

13. Performance and troubleshooting

CPU

CPU cost depends on the active engines and effects. Plaits physical models and Clouds Reverb are heavier than basic AY voices. Check performance on the target console, especially with 8 Plaits voices and both sends active. A CPU reading near 100% can cause crackles or missed audio deadlines.

The CPU display is a smoothed measure of audio rendering time. It does not measure delays before the audio callback runs or in the device’s audio output, so crackles can occur even with a low reading.

On Android, audio output now prefers AAudio to avoid intermittent crackling observed with OpenSL ES on the Pixel 7a. This buffered output prioritises stable playback and can add some response latency. The tracker canvas keeps its full 4:3 layout on square and other unusual screen ratios; unused space is shown as borders rather than cropping columns. If crackling persists, report the song, phone model, Android version and whether you are using the speaker, headphones or Bluetooth.

If you run into pops, crashes or slowdowns, use Settings > Support report and attach the generated support-report.txt to the bug report. If a specific song triggers the problem, attach that .cct too.

No sound

Check the instrument number, track mute or solo state, track LVL, application Mix volume and instrument envelope. For samples, check that the original WAV still exists at its saved path. On ArkOS, press MENU + L3 to toggle the operating system mute. If that does not help, restart the hardware and reconnect your audio interface.

Input feels wrong

Adjust Repeat delay and Repeat speed in Settings. If a single press moves twice, check that only 1 physical control is mapped to that direction and report the exact screen and shortcut.

14. MIDI

Desktop and PortMaster. Settings > MIDI opens this submenu: MIDI In / MIDI Out pick a connected device, cycling through detected ports with OFF at either end; both directions need a device selected. The device selection is per session: it is not saved to settings.txt, since a port’s position in the list can change across reboots or when devices are plugged in a different order. The app’s PLAY control remains available from this screen and starts the song. On PortMaster, connect a USB MIDI device before launching; it must be exposed by the handheld’s OS through ALSA.

• Sound preview from a MIDI keyboard: with a MIDI In device selected, playing notes on the connected keyboard auditions an instrument on any screen, the same as the on-screen EDIT + PLAY shortcut on the Instrument screen. This is preview only - it does not enter notes into the song.
• Channel mapping: opens a list of the 16 MIDI channels; assign each one an instrument (OFF by default) so notes received on that channel preview that instrument regardless of which one is selected on the Instrument screen - e.g. channel 01 -> instrument 05. A channel left OFF falls back to the currently selected instrument, the original behavior. This mapping is saved to settings.txt.
• MIDI CC mapping: maps an incoming controller to an instrument parameter, including its Volume, or to global controls. Global rows show TRK 1-TRK 8 instead of an instrument and provide track Mute, Solo, Volume, Reverb send, and Delay send; Song play/stop has no target. A new mapping ignores the CC that learned/configured it and takes effect on the next physical movement, so setting up mappings during playback cannot reset a patch to zero. Mute and solo use 0-63 = off, 64-127 = on.
• Driving an external MIDI device: give a track the MIDI Out instrument type and set its Channel; triggering notes on that track sends real MIDI to the selected MIDI Out device instead of making sound in ChooChooTracker.
• Send clock / Send transport: in Settings > MIDI, select a MIDI Out device and enable either switch as needed. Both default to OFF and are remembered for this device. Send clock sends 24 pulses per quarter note during sequencer playback, following the internal tempo or the Ableton Link session. Send transport sends Start when playback begins and Stop when it ends; note and row previews do not start external gear. Each playback starts the receiver from its beginning; Continue and song-position pointers are not sent. Both outputs are suppressed while Sync is MIDI to prevent feedback; the switches retain their settings. Enable external MIDI sync on the receiving device.
• MIDI delay: delay the outgoing notes, controllers, clock and transport together by 0–200 ms to align an external synth with ChooChooTracker’s audio output. Start at 0 ms, then increase it if the external synth sounds early. Compare short attacks recorded together and fine-tune in 1 ms steps; larger edits move by 10 ms. The setting is saved. Switching between the console jack and a USB audio interface may require a different value.
• MIDI clock sync: with a MIDI In device selected, set the Project screen’s Sync to MIDI to follow an external sequencer. The tracker measures tempo from the incoming clock (24 pulses per quarter note) and shows it on the greyed-out Tempo row; Start, Continue and Stop messages control playback. The clock source is remembered in settings.txt.

15. Credits and licensing

ChooChooTracker is a fork of ChipNomad and retains its MIT licensing approach. Braids, Plaits, Plaits-Alt, Clouds DSP, Warps-derived MME DSP and stmlib code are derived from Mutable Instruments’ open-source releases under their applicable MIT notices. Plaits-Alt is sourced from the lylepmills/eurorack Plaits Lab fork; its retained source notices apply. The aChChid engine uses Open303 by Robin Schmidt, copyright 2009, under the MIT License. MonkSynth uses JonET’s native DSP under the MIT License; see LICENSE.monksynth.txt. Bogie and Sintered are original native implementations. MIDI I/O uses RtMidi by Gary P. Scavone, under its MIT-style license. See the packaged license files for exact attribution.

Track insert effects

Each of the eight tracks has two serial slots, TF1 → TF2. From Instrument, use the usual Shift+Up gesture to open MOD, then Shift+Up again for F: Insert FX. Shift+Down returns to MOD. OPT+Left/Right selects the track (1–8), without changing the instrument selector. The module header opens the existing chooser; bypass retains the module, configured values, and automation. Parameters are byte values: left column 1–4, right column 5–8. Context text shows full names and decoded values. Old projects load with both slots OFF.

The navigation display keeps the full F–M–I–P column visible throughout the instrument screens, including Insert FX and the instrument pool, and highlights the current screen.

Continuous controls use 00–FF, except FORMANT VOW (00–7F). Bipolar controls have an exact neutral at 80. Distortion modes are 00 Density, 01 Drive, 02 Spiral, 03 Mojo, 04 Dyno. Compressor ratios 00–07 are 1.5, 2, 3, 4, 6, 8, 16, 20:1. Compressor Detect 00–02 listens to its own stereo input, left, or right; 03–0A listens to tracks 1–8 instead. Detector filter 80 is neutral, below is low-pass, above is high-pass. A track source is taken after its volume, pan and Tilt EQ but before its inserts; a muted or absent source supplies silence. Either slot can contain any module; repeated modules are independent. Chorus, Flanger, Phaser and Rotary use gentle modulation defaults. Rotary Speed uses the full 00-FF range: 00 = 0.01 Hz (one rotation per 100 seconds), FF = 25 Hz (the former Chaos maximum). Exponential spacing gives finer control over slow LFO movement. New Rotary inserts default to 8F, about 0.8 Hz. This replaces the four discrete speed values; existing Rotary settings and F11/F21 speed automation need retuning to the new scale (old Slow/Fast/Hyper/ Chaos correspond approximately to 8F/CB/E7/FF). Other parameters are unchanged. Bitcrusher bit depth ranges from 4 to 16 bits and rate reduction from 1x to 32x. Destruction processes Crush and Rate first, then Fold, asymmetric Distort and hard-clip Saturate. The controls follow the audio chain: F11/F12 set Crush/Rate, so later stages reshape their digital grain. Each stage is off at 00. Values 00-7F cover the normal range and 80-FF extend it: Fold, Distort and Saturate reach about 8x drive at 7F and 32x at FF; Crush reaches 4 bits then 1 bit. Rate reduces the sample rate from 1x through 16x at 7F to 128x at FF, and can be used independently of Crush’s bit reduction. Input adds up to 12 dB at 7F and 36 dB at FF. Tone is a post-effect low-pass filter, bypassed at FF. A shared stereo auto-level stage smooths level changes and limits its correction to -36/+18 dB; very quiet or strongly cancelled signals can still change in perceived loudness. Existing projects retain their Destruction bytes without conversion. Its old parameters are reinterpreted, so an old project can sound different or dry until Mix and the stages are edited. Saturation and distortion include output level or mix controls for balancing them against the unprocessed signal.

Track level and tilt EQ precede the inserts, so both affect the signal entering compression and distortion. All voices/chord notes on the track feed one insert chain. Both reverb and delay sends receive its output. Shared effects, returns, master controls and mute/solo retain their existing behavior. Inserts do not process audio from external MIDI devices.

Insert commands use F11–F18 for TF1 and F21–F28 for TF2. The roll’s FX selection and Phrase/Table popup offer only parameters used by the selected track’s configured inserts. The popup groups them as TF1: effect name and TF2: effect name; OFF slots are hidden. Bypassed inserts remain editable. In the Phrase and Table FX popup, the description follows the selected track’s insert slot: it shows the module, parameter name, decoded range endpoints and saved base value. Existing song commands are preserved if a module change makes them unused; opening their picker starts at an available control. While editing a value, the bottom hint shows its decoded value and units. Any Phrase or Table FX column can address either slot; the Phrase grid keeps its three columns. These absolute runtime values persist across notes, instruments, phrases, chains and ordinary loops. Fresh playback/hard stop resets them. Editing a base value on the F page clears only that parameter’s override. MOD acts on the effective base/automation value without saving its offsets. Selecting a new module restores defaults and clears that slot’s overrides. Bypass retains existing automation while suspending processing after a short fade.

Addresses refer to track slots/parameter positions, not named effects. A Phrase reused on another track uses that track’s modules. Changing modules can change a command’s meaning; commands are not rewritten. OFF/unused addresses are safe no-ops and remain intact in saved Phrase/Table data.

The instrument MOD chooser adds an Insert FX category. Each instrument’s sources control inserts on whichever track plays it, including the combined chord signal. The same instrument on two tracks affects independent chains. Existing source timing, signed amounts, source-combination rules, stick modes and motion recording apply. Discrete controls are quantized and clamped to valid choices. There is no new track-owned modulation bank.

Compressor makeup starts at 0 dB. OTT starts at approximately 25% depth, 25% upward, 50% downward, 0 dB input and -3 dB output. Its band thresholds, gains and crossovers remain at Rui-727’s native defaults; Depth is its wet/dry control. TAPESCAM retains native auxiliary defaults: new/high-speed tape, noise and compression off, widening on. Watch existing clipping indicators when adding drive/gain. Slot transitions use bounded 5 ms fades via dry audio.

Saves store module IDs, bypass and configured bytes in the optional versioned Track inserts: 1,8,2 section. Runtime overrides and DSP histories are not saved. Keep backups before opening insert-enabled saves in older builds. DSP attribution, source revisions and adaptations are in chipnomad_lib/external/insert_fx/SOURCES.txt; full MIT notices ship in licenses/INSERT_FX.txt.

On an R36H at 48 kHz, a measured pair of inserts on one track took about 4–5% of real time for Compressor, 6% for Distortion, 18% for Doubler, 16% for TAPESCAM, and 24% for OTT, before the cost of the synths and shared effects. Sixteen active Doubler, TAPESCAM or OTT instances exceeded real time. Audio-rate modulation adds further cost. Start with a few inserts, watch for audio overload, and bypass unused slots; the sixteen available positions are not a guaranteed CPU budget.

The Insert page keeps the selected field’s tip visible after button release; temporary notices can still take its place. The module chooser shows each module’s effect type and source project alongside its name.

Make a kick pump the mix or another track

For a pumping master, put the kick on track 1, select Compressor in MASTER FX, set Detect to 03 (Track 1), Ratio to 04 (6:1), Attack around 60 (about 1.6 ms), Release around C0 (about 115 ms), Makeup to 00 and Mix to FF. Lower Threshold until the other sounds dip with each kick, then adjust Release so they recover before the next one. The kick’s direct sound keeps its own track inserts but bypasses both master insert slots; its reverb and delay returns still pump.

To duck only a bass, pad or synth, put its Compressor on that track and select the kick track with Detect. The source kick remains audible and its volume is not changed by that track’s compressor. A kick and bass combined on the same track cannot be separated by this routing.

FORMANT

Select FORMANT in TF1 or TF2 to shape a sound into vowel-like tones. It works best on a sustained, harmonically rich source such as a saw wave.

Set MODE to 00 VOW and use VOW to sweep from A (00) through E, I and O to U (7F). Set MODE to 01 CUSTOM to tune F1 and F2 yourself instead. RES narrows or broadens the vowel character; MIX blends the effect with the original signal. Use MOD → INSERT FX to move the active controls. MODE is not a MOD destination.

Native OPLL and VRC7 instruments (development)

The Instrument Type selector has an FM group with OPLL / MSX (YM2413) and VRC7 (DS1001). Each now offers 73 programs in scrolling Bank / Preset lists: the original 15 tones, 40 additional distinct tones from emu2413’s YM2413/VRC7/YMF281B tables, and 18 ChooChoo-authored two-operator programs. Exact duplicate tone bytes are omitted within each engine. The additional palettes use the chip’s programmable tone slot; they do not expand the physical ROM. Program zero identifies a custom tone. EDIT + left/right selects the previous or next preset within the bank filter. Fine ct adjusts tuning from -100 to +100 cents.

In the program list, EDIT + PLAY auditions the highlighted sound; release the buttons to stop. EDIT commits and OPT cancels. Browsing/audition does not change the instrument, table or song. The normal Instrument-page audition gesture continues to work after selection. Native chip envelopes supply attack/release; the optional Amp env adds a software ADSR (see Native chip controls below). There is no full operator editor.

New instruments store all eight native tone bytes, bank/name, program and fine tuning in the song/instrument file. Files containing these types use format 7.0 and need this build or later. Earlier formats remain readable; songs without these types continue to save as 5.0. Rhythm programs are deferred. The expanded library is validated on the host; human listening and a new handheld check remain pending.

AdLib / OPL2 and OPL3 (development)

FM also includes AdLib / OPL2 (YM3812) and OPL3 (YMF262). Bank filters the factory list; Preset opens category groups and an All view. EDIT + PLAY auditions before selection, EDIT selects, OPT cancels, and EDIT + left/right on Preset loads the previous/next matching entry. Fine ct adjusts local tuning. Mode shows 2 operator, 4 operator, or Dual voice. OPL2 hides incompatible OPL3 patches; OPL3 can play the shared two-operator collection.

Bank and preset popup titles identify the current engine. Switching engine or instrument slot resets the bank filter to All banks, including switching between the compatible AdLib and OPL3 engines. Returning from a popup within the same slot keeps the chosen filter. Cancelling a DX7 bank import restores the previous filter.

Preset confirmation also publishes edits made on button release to the next UI/audio tick. Playing songs no longer need another button press or a transport restart to receive that patch. Output still follows the configured audio buffer and the engine’s envelope/retrigger behavior.

The factory collection contains 697 source entries from The Fat Man 2-op, The Fat Man 4-op and DMXOPL3, with 589 normalized unique patch identities. Aliases retain source names and attribution. Source-native operator levels, LFO-depth flags, note offsets, fixed percussion pitches and dual-voice tuning are retained. Tracker volume uses software amplitude; it does not reproduce the original MIDI players’ volume curves or velocity-offset policies. Source release-duration estimates do not cut off sustained notes. Some effects have slow attacks: hold Seashore rather than expecting a short click to reveal it.

Factory assets live in instruments/chips alongside the existing instrument library, with notices under licenses/chip-banks. Preset selection leaves the slot’s table and track-owned inserts unchanged. Newly saved files use 7.0 and embed the complete tone. Factory audio is machine-tested on host and ARM64; human audition remains pending.

Sega PSG and Game Boy native instruments (development)

CHIP now includes Sega PSG, GB Pulse and GB Noise. Sega uses the NTSC master clock and its 16-bit noise feedback, including tone-channel-derived noise. Its default Bass range: Extended lowers the virtual clock when needed to play below the chip’s approximately 109 Hz divider limit. This keeps A-2, G-2 and F-2 distinct. Choose Chip for the original range, where lower notes converge on the divider limit. Fixed-rate noise keeps the original clock; tone-derived noise follows the extended pitch. Old Sega instruments load with Extended enabled; the setting is saved with the instrument. The GB instruments use DMG pulse/noise registers; no Game Boy wave channel is exposed. Their authored preset lists now contain 24, 24 and 28 presets respectively. The additions cover linked/periodic Sega noise, GB pitch sweeps, short percussion, metallic noise, drones and rises. These are original programs, not extracted game sounds. The page offers native mode/duty/width, envelope/sweep/noise controls as applicable, plus a software amplitude ADSR. These save in version-6 native files. Automated ARM64 performance/audio checks pass within the reported workload limits; human listening remains pending.

DX7 FM (development)

Select Type → FM → DX7 FM; DX7 is the seventh entry, after Arcade / YM2151. DX7 FM uses a six-operator MSFA core. The existing FM page offers Bank, Preset and Fine ct alongside common instrument settings. Preset browsing uses bank/category lists. Hold EDIT+PLAY to hear the highlighted sound; releasing stops audition. EDIT alone commits on release; OPT cancels. Loading a sound copies its complete patch without changing tracker tables or track insert FX.

The factory catalogue currently contains 67 distinct DX7 parameter patches: 31 OpenDX7 original musical sounds, four unique YSE CC0 sounds (its 32 bank slots repeat those four with different names), and 32 ChooChoo-authored patches. Here, “original” means parameter programs created for this project; it does not mean original Yamaha factory content. YSE is shipped as four sounds, not 32 artificially different names. Categories describe the reviewed sound-design intent. Ambiguous names remain Unsorted. Numerical playability checks have passed; listening acceptance is pending. The separate goal of 1,000 redistribution-cleared sounds is not met.

For a persistent personal library, put .syx files in instruments/banks/dx7/ beside the existing instrument library. Subfolders are supported. Open DX7 → Bank: each file appears as a named bank, ready for Preset browsing. Reopen Bank after adding or removing files; no conversion or Load Instrument step is needed. A standard original DX7/TX7 bank contains 32 voices. A file with four bank messages appears as four numbered banks (128 voices total). Single-voice files are accepted too. The native application reads this folder; the browser build reads its virtual filesystem, not arbitrary folders on the computer.

Bad or unsupported files are skipped with an on-screen count; valid banks remain available. Scanning is bounded to 2,048 files, 1 MiB per file, 64 MiB total, 60,000 voices and eight levels of nested folders. Symlinks are ignored. The selected patch is owned by the instrument: removing its source bank cannot change the saved song. The complete browsing library stays in this folder and is not copied wholesale into each project.

LOAD INSTRUMENT also accepts .syx original DX7/TX7 single-voice and 32-voice bank dumps, including bounded sequences of those supported messages. It checks framing, byte counts, seven-bit data, checksums, parameter ranges and file size before opening the imported bank in the same FM browser. Selecting a patch commits; cancel keeps the current song instrument. This direct-import shortcut keeps its browsing list for the session; use the bank folder above for persistent browsing. Save the song or a .cni to retain selected/edited patches. Headerless dumps, bad checksums, DX7II performance/extensions and other Yamaha families are rejected. Import never sends MIDI messages to external equipment.

CNI and project version 6 store all 155 original voice bytes, the full display name, native strike velocity, fine tuning and source identity. Songs need no external bank to reopen. Older ChooChoo releases cannot read these version-7 files; existing-only projects still save as version 5. Native velocity defaults to 100; tracker volume is post-synthesis gain and does not restrike the envelope. Operator envelopes, fixed-frequency mode, keyboard scaling, pitch envelope and LFO remain native patch behavior. The optional common FM amplitude ADSR shapes their combined output without replacing the operator envelopes.

Each track part has one LFO and four separately owned chord voice slots, matching the existing tracker chord/replacement policy. Tracks do not share note state. Note-off releases the native envelopes; cut/panic clears them. The scalar MSFA core uses 64-sample quanta at a fixed internal 44.1 kHz, with a streaming FIR to the output rate. Lookup tables are initialized once outside audio rendering so concurrent offline/live renderers cannot change one another’s rate. Events take effect at the next internal quantum (up to 1.45 ms), followed by the FIR’s approximately 0.25 ms group delay. Buffered samples are retained across callbacks. This is the MSFA Modern lineage, not a claim of bit-identical DX7 hardware or a Dexed Mark I emulation. DX7 is limited to 16 active notes across the song, including release tails, while retaining four owned chord slots per track. When over budget, it takes release tails first, then the quietest held notes, then fresh attacks. Equal attacks retain root notes across tracks before chord extensions, with stable slot/track tie breaking. This policy applies on every platform so the same song has the same bounded note allocation. It does not change other instruments’ polyphony. Preset audition is disabled during playback. The limit was selected from R36H measurements and validated in mixed playback.

FM operator editor

Genesis FM, Arcade FM, OPL2, OPL3, OPLL and VRC7 instruments have an EDIT button to the right of Fine ct. It opens a table of the patch parameters:

• Genesis FM / Arcade FM
• OPL2 / OPL3: on OPL3 the mode (2op, 4op, dual) can be changed here.
• OPLL / VRC7: editing a ROM preset turns it into “Custom”.

Left/Right and the usual edit keys change values; the instrument keeps playing as usual so you can hear changes. The status bar describes the parameter under the cursor. OPT or Left+Shift returns to the instrument screen. DX7 and SID have no operator editor.

Genesis FM (YM2612) and Arcade FM (YM2151) now use the same FM Bank/Preset browser, EDIT+PLAY audition, confirm/cancel and fine-tune controls. Genesis now has 73 presets: the original 24 and 49 supported melodic programs from NeoSoundFonts’ CC0 16-Bit FM Music Station bank. Arcade has 81 presets: the original 24 and 57 supported, sounding programs from YMulator-Synth’s GPLv3 collection. The original ChooChoo pair shares its underlying recipes; the new source collections provide separate palettes. These are named sound-design collections, not claimed recreations of particular game soundtracks. Unsupported note offsets, fixed percussion keys, arcade noise settings and silent source programs are recorded as exclusions in expansion-manifest.json. Their complete four-operator patch, envelope, LFO, stereo and tuning settings travel inside version-6 instruments and songs. The native chip envelope controls release; ordinary tracker gain and pitch do not restart it. Genesis DAC output uses a 20 Hz DC blocker. Noise mode and channel-3 special-frequency mode are outside this instrument implementation.

For a local external bank, use tools/chip_banks/import_bank.py SOURCE --output NEW_DIRECTORY --writer tracker/build/tests/chip_factory. It accepts strict 42-byte TFI, VOPM OPM text, the verified WOPLX format and original-DX7 SysEx. Load the resulting .cni files through Load Instrument. User imports are kept separate from the distributable factory library. OPM files with noise enabled, nonzero noise-frequency data or partial panning are rejected with an explanation; VOPM pan values 0/64/127 become left/both/right. Binary WOPL is not supported. The shared FM catalogue contains 1,064 entries: 697 OPL, 67 DX7, 146 OPLL/VRC7, 73 Genesis and 81 Arcade. Another 76 files expose the Sega/Game Boy presets through the normal file browser, for 1,140 packaged native presets. Source revisions, hashes, full notices and original source data accompany the new collections under licenses/chip-banks/expansion.

Portable factory collections and USER presets

Native chip instruments use Bank: to choose ALL, an included collection or USER. Preset: chooses a sound within that selection. Hold EDIT and press Left or Right on either row to cycle; a short EDIT tap opens its chooser.

Included collections are ZIP packs under instruments/FACTORY/. USER files go under instruments/USER/<engine>/: dx7, opll, vrc7, opl2, opl3, genesis, arcade, sid, sega, gb-pulse, or gb-noise. Browse folders directly or put a ZIP of compatible presets there. ZIPs remain intact on disk. All these folders accept compatible .cni files; CNI is ChooChoo/ChipNomad’s portable instrument format, not a chip manufacturer’s standard. The USER browser also reads the following source formats, including inside ZIPs:

A bank opens into compatible voices. Unsupported files or features report a reason; incompatible voices in a mixed bank are excluded while their source numbers remain stable. Loading is transactional: a rejected preset leaves the current instrument unchanged. Source presets replace the instrument’s tracker table with an empty one, except DX7 SysEx, which preserves its existing table. CNI restores its saved table. Loaded patches are owned by the song and continue to work after moving or deleting the source pack.

WOPL banks can contain unused slots without an explicit blank flag. The browser omits unnamed slots whose active operators are fully attenuated and have no attack. Unnamed playable voices remain available as Program N [Bbank] or Drum N [Bbank], using the source’s zero-based program and bank numbers. An unnamed single OPLI instrument uses its filename. Named silent patches are retained.

Furnace support covers legacy single-instrument versions 29–112 and feature-based FINS versions 127–251. DefleMask support covers version 11 OPN, OPM, Sega PSG and Game Boy instruments. These are instrument imports, not complete tracker players: animated FM/operator macros, source-song FM LFO settings, samples, Game Boy hardware command sequences, relative SID pulse/filter macros and SID ring/sync dependencies are currently rejected. Constant OPLL ROM selection is supported; VRC7 uses its own ROM for that selection. SID-Wizard .swi and SID music files (.sid) are not instrument imports in this build.

Supported PSG/GB/SID sequences are stored in the patch and played at 60 Hz for Furnace/DefleMask and 50 Hz for GoatTracker. Those files do not carry a complete song’s playback configuration: use the original tracker when its song-specific tick rate, channel routing, hard-restart behavior or compatibility settings are required. For Sega PSG, a duty macro selects the noise voice; without one the import uses a tone voice. Game Boy files must be placed in the intended pulse or noise folder. Imported sequences currently remain embedded playback data; the instrument page edits base parameters, not the source tracker tables.

USER preset cycling continues across files, folders, banks and ZIP packs in both directions, wrapping at the ends. Reopening the USER browser follows the current selection. ALL includes USER sounds under Unsorted for categorized engines; USER remains a separate top-level choice. Sega PSG and Game Boy use flat ALL/Factory lists and a hierarchical USER browser, without an Unsorted panel. Older DX7 files in instruments/banks/dx7/ remain accessible in USER.

An engine shows only its compatible included collections. Factory Presets combines the included OPLL/VRC7 tone sets for the selected engine; DX7 combines ChooChoo and YSE originals. Downloaded named collections remain separate. Fat Man 2-op is listed under OPL2 and Fat Man 4-op under OPL3. Compatible OPL2 CNI files may still be used in OPL3 USER folders.

Native-engine output uses fixed measured gain compensation rather than per-preset normalization. Existing native-instrument songs can therefore play at a different level; review the balance of saved mixes. The calibration method and bounds are documented in scripts/README_MEASURE.md.

native-chip-audition.cct provides a short sequential audition across the original thirteen factory banks. Each section uses a different owned instrument, so it works with the preset folder removed. Longer ignored bank WAVs and measured levels are listed in docs/chip-preset-auditions.tsv; subjective listening remains pending.

Native chip controls

Native instrument waveform previews refresh when their controls are redrawn. FM instruments can overlay their optional Amp env curve; SID keeps its waveform preview without that FM-only overlay, including when browsing banks and presets.

All seven FM engines offer Bright, Feedback, and Amp env. Bright ranges from -63 to +63, with zero preserving the patch; it changes modulation operator levels while retaining carrier levels. Its audible effect depends on the algorithm. Feedback defaults to Preset, or overrides the native feedback with 0–7. These controls do not rewrite the saved native operator bytes.

Amp env defaults to Bypass. Select ADSR to add attack, decay, sustain, release and shape around the native sound. A/D/R use the shared 0–5 second quadratic range; sustain runs from silence to full level. Native envelopes still run, so this envelope cannot extend a sound beyond its native release. Preset browsing preserves the slot’s FM amp and tone controls. All FM voices also use a 3 ms onset/retrigger transition and 1 ms tracker-gain smoothing, including when Amp env is bypassed. Hard cut/panic remains immediate.

The following phrase FX also appear as supported Modulation and motion-recording destinations. Values in the FX column are hexadecimal. Settings apply to playback without changing the saved instrument. Native GB sweep and envelope controls latch at the next note trigger; duty/width and noise frequency can change live.

Native FX selection uses the instrument in the phrase row’s I column, or the active instrument found by looking backward when I is blank. The FX popup shows a short control description, its current preset value and valid command range in a compact block. Selecting a different native effect starts at that value; reopening the same effect preserves its edited value. A multi-row selection resolves each row’s instrument separately. Tables use their instrument context. Native value edits stop at their legal endpoints, including duty, noise, sweep, ADSR, feedback and operator levels. The values are hexadecimal: for example, DX7’s maximum 63 means decimal 99.

These FM commands use absolute native values. Operator commands always target operator 1; OMU 03 selects its multiplier 3. DX7’s tracker-specific controls are operator levels and feedback. Preset/Range keeps its information color; titles and descriptions follow the same colors as FM Feedback.

Live Modulation retains its full set of fixed-operator native destinations. Motion recording writes only controls represented by the compact tracker list; operator parameters record for operator 1 only. Other modulation destinations continue to work live but do not generate phrase commands.

SCP and SCT retain byte-scaled mappings to SID registers wider than 8 bits. SMR 01–C8, SWV 01–08 and SPR 01–10 now match the native preset numbering. Displayed preset values are base settings, independent of the playing envelope or LFO. SLE works on operator levels and the direct FM parameters without retriggering the note or changing the stored patch.

All native FX have descriptive titles, ranges and behavior in the phrase FX chooser, plus value hints. CMD describes tone/noise, duty or noise width according to the selected instrument. These controls supplement the shared Track, Envelope and Modulation groups; the engine group alone is not the full set of available phrase effects.

The existing shared LP/BP/HP filters on Braids, Plaits, PCM and other supported engines are software processing after synthesis. aChChid instead uses its native 303 filter path. This round adds no filter to AY or native FM; brightness changes FM synthesis itself. Track inserts remain available for additional processing.

Native instruments save in CNI version 7 (8 when absolute commands are present), and native songs in CCT version 9. Instruments containing imported sequences use CNI version 9 and songs containing them use CCT version 10. Older builds cannot open those newer sequence-bearing files. Stored FM preset bytes and instrument-page tone settings remain unchanged.

Handheld workload guidance for native chips

There are eight song tracks and two insert-effect slots per track. The sixteen available slots do not guarantee enough CPU to run sixteen effects. DX7’s sixteen-active-note limit is a separate song-wide synthesis budget; chords and release tails count toward it.

In R36H measurements, four looping WAV tracks, Sega PSG, GB Pulse, DX7 and OPL3 with shared sends and four inserts (two Compressors, Doubler, TAPESCAM) performed better than dense eight-track FM arrangements. The single-note version had no render deadline misses in its thirty-second 48 kHz/512-frame measurement; adding a four-note DX7 chord had one timing spike. Dense FM songs with many expensive inserts exceeded the CPU budget. Preserve some headroom, watch the existing overload indicator, and add effects where they help the song. The app retains every track and slot; there is no new hard limit on insert count. See chip-instruments-report.md for full measurements and sustained-test status.

The matching 70-second physical audio test of that balanced chord arrangement passed with no render deadline misses or logged ALSA underruns at the existing 48 kHz / 4906-frame setting. Its worst callback was 81.819 ms against a 102.208 ms deadline. Tests used a separate master gain of 0.4 for headroom. Keep the regular launcher’s direct-card AUDIODEV=plughw:0,0 route: the system’s default shared mixer produced underruns in the diagnostic probes. No user audio setting was changed. The ten-minute smaller-buffer stress test still recorded 28 timing spikes; the complete results are in the report.

SID instruments and Phrase FX

Choose CHIP → SID. Bank offers ChooChoo SID Originals (32 authored programs) and SIDkit Effects (24 MIT-licensed effects). Both use the same preset browser and save their complete selected program inside the instrument and song. No external bank is required when sharing the song. These are native SID parameter programs with envelopes and motion recipes, not sampled audio or complete C64 songs. The separate twelve GoatTracker research candidates are not shipped; their wave/pulse/filter tables need a dedicated importer/player.

The instrument page exposes waveform/pulse width, filter mode/cutoff/resonance and native ADSR controls. SID uses the pinned floooh/chips digital oscillator, envelope and per-cycle 6581-style filter. There are no alternate chip models, revision selectors or added character profiles. This is a generic approximation, not a calibrated R2/R3/R4/8580 analogue model.

Each note has its own filter. Ring/sync use a silent partner oscillator, so filter sharing and three-voice interactions differ from a physical SID. The handheld has a song-wide budget of four ordinary SID notes. Ring or sync costs two budget units per note, allowing two such notes, or one plus two ordinary notes. Chords and release tails count. Released notes are retired first; new notes take priority over older held notes. Expensive inserts and other synths still share the audio CPU budget.

Pulse width and cutoff support SLE. Discrete waveforms, switches, resonance and FM feedback retain their useful native steps; wider byte values would not create more hardware states. FBK directly selects feedback 00–07. Operator levels use the engine-specific ranges listed above. Brightness and master adjustments retain the full byte range.

Portable factory collections and USER presets

Native chip instruments use Bank: to choose ALL, an included collection or USER. Preset: chooses a sound within that selection. Hold EDIT and press Left or Right on either row to cycle; a short EDIT tap opens its chooser.

Included collections are ZIP packs under instruments/FACTORY/. USER files go under instruments/USER/<engine>/: dx7, opll, vrc7, opl2, opl3, genesis, arcade, sid, sega, gb-pulse, or gb-noise. Browse your folders directly, or put a ZIP of folders and compatible .cni presets there. DX7 also accepts supported .syx single voices and 32-voice banks, including inside ZIPs. ZIPs remain intact on disk. Direct WOPL/WOPLX loading is not supported; use compatible CNI presets or convert supported source formats offline first.

USER preset cycling continues across files, folders, banks and ZIP packs in both directions, wrapping at the ends. Reopening the USER browser follows the current selection. ALL includes USER sounds under Unsorted for categorized engines; USER remains a separate top-level choice. Sega PSG and Game Boy use flat ALL/Factory lists and a hierarchical USER browser, without an Unsorted panel. Older DX7 files in instruments/banks/dx7/ remain accessible in USER.

An engine shows only its compatible included collections. Factory Presets combines the included OPLL/VRC7 tone sets for the selected engine; DX7 combines ChooChoo and YSE originals. Downloaded named collections remain separate. Fat Man 2-op is listed under OPL2 and Fat Man 4-op under OPL3. Compatible OPL2 CNI files may still be used in OPL3 USER folders.

Native-engine output uses fixed measured gain compensation rather than per-preset normalization. Existing native-instrument songs can therefore play at a different level; review the balance of saved mixes. The calibration method and bounds are documented in scripts/README_MEASURE.md.

SoundFont collection browsing

In SAMPLE → SOUNDFONT, Preset opens your collections. Right or EDIT/A enters a folder directly. In a leaf collection, Right moves to its presets; another Right pages forward by 15 entries without loading. EDIT/A loads the highlighted preset. Left returns to collections, then to the parent folder; OPT also goes back. PLAY starts/stops the song while browsing.

Folder and sound icons identify the entries. Collections use their full panel height. The selected preset stays below the eight track previews; long names scroll after one second of idle selection and restart when you move. EDIT+Left/Right on the instrument page follows the same nested folder order, keeping each collection’s sounds together. EDIT+PLAY auditions.

The third row reports Reading preset, Finding samples, Unzipping, Checking samples or Loading samples. EXS instruments with empty or (null) embedded names use their filenames. Source banks and audio stay unchanged. Use Rescan after changing your library files.

See format coverage and limits for supported sampler behavior and sample formats.