sandlbn / polyend-tracker-re

OpenTracker is an open-source, clean-room firmware for the **original Polyend Tracker**,
written from behavioural specifications. It contains no Polyend code, fonts, icons or
graphics, and is not affiliated with or endorsed by Polyend.
## Screenshots (2.0.1, on an original Tracker)
| Pattern | Config: USB Storage |
|---|---|
| | |
| **Sample Recorder** | **Synth Parameters: Load Patch** |
| | |
2.0 brings the newer Tracker features to the original hardware: 16 tracks, synth
engines, stereo samples, Mini-compatible project files and USB Storage mode. These notes cover
the whole 2.x line 
## New in 2.0
### Tracker Mini project compatibility
- Projects are saved in the **Tracker 2.2.1 format**: 16-track patterns, the three
 synth slots, track names and mutes for tracks 13–16.
- **Synth patches** use the Mini's `.patch` files. They are stored with the project and in a
 library at `Patches/ /`. All 299 Mini factory patches load and save back unchanged.
- Older original-Tracker projects open as they are, with tracks 13–16 empty.
### 16 tracks
- Tracks 13–16 work like MIDI tracks 9–12: notes, MIDI channels, CC A–F, pitch bend,
 velocity, mute and solo. Performance Play mode, Pattern length and Step repeater act on them
 too (no voice FX, levels or per-track patterns, as on the Mini).
- Pattern pages through all 16 tracks. Song shows a scrolling 12-track window.
- Fill, copy and paste work across all 16 tracks.
### Synth engines (instruments S1–S3)
- **Three synth slots**, played from any track as instruments S1–S3.
- Three engines, our own sound design following the Mini's parameter sets:
 - **ACD**: acid bass and lead, with a 24 dB and a ladder-style filter, and glide;
 - **VAP**: virtual-analog poly, with morphing oscillators, hard sync, 15 filter types and a
 6-slot modulation matrix;
 - **PERC**: drum kit with kick, snare, hats, cymbal, perc and tom.
- **WTFM and FAT** patches load and save unchanged, but stay silent and show
 "not available" until 2.1.
- **Macros:** FX columns A–F drive macros 1–6, and Volume drives macro 7.
- **Voices:** a shared pool of 4 voices by default, adjustable in Config > General > Synth
 voices (1–8).
- **Screens, after the Mini's layout:**
 - Synth Parameters: model, polyphony, gain, pan, sends.
 - Synth Macros.
 - Edit Patch: sections on the pads; Save, Save As, Init.
 - Load Patch popup with Preview.
 - Synth 1–3 level columns with meters on Global Mixer page 3.
- Exports include separate stems `synth_1..3.wav`.
### Stereo samples
- Stereo WAVs keep both channels on import.
- They play in stereo in one-shot, loop, slice and beat-slice modes. Pan works as balance.
### Performance and monitoring
- **CPU meter** in the title bar (Config > General > CPU meter: Auto, Always or Off).
- **Voice limiter:** if the audio gets close to its limit, only synth voices are cut; sample
 tracks never are.
- **Faster loading:** project loading does about half the work in our host model (not yet
 timed on the device).
- **Smoother displa