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.

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

• 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/<ENGINE>/. All 299 Mini factory patches load and save back unchanged.
• Older original-Tracker projects open as they are, with tracks 13–16 empty.

• 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.

• 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 WAVs keep both channels on import.
• They play in stereo in one-shot, loop, slice and beat-slice modes. Pan works as balance.

• 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 display: frames go to the screen over DMA without waiting.
• More code in fast internal RAM: the hottest audio and synth code runs from it.
• USB serial diagnostics: CPU, peak breakdown, display, SD and radio/recorder lines.

• Config > USB > USB Storage: On shows the SD card on a connected computer as a USB drive, as on the Tracker Mini. Copy projects, samples and patches without taking the card out.
• Playback stops and the project is saved first. Keep the power and the USB cable connected while files are transferred.
• To finish: eject the drive on the computer, then press Exit (or set the row back to Off). The project reloads from the card. If the computer still uses the drive, Exit first reminds you to eject it.
• The setting is always Off after power-on.
• About 1 MB/s (full-speed USB; measured 1,033 KB/s on a real Tracker). Tested with Linux and macOS; Linux can take a few seconds longer to notice the drive. USB MIDI and the serial log keep working.
• If the cable is pulled during a transfer, the Tracker recovers within half a second.
• The drive has a stable serial number, so a computer keeps recognising the same Tracker. On Windows, the Tracker may appear once as a new device (new COM/MIDI port).

1. Copy PolyendTrackerOTv201.ptf to /Firmware on the SD card. Keep the name; the bootloader only accepts 24-character names.
2. Go to Config > Firmware update, select it and confirm. If the screen stays dark after the update, press the power button once.

Going back: keep the stock PolyendTracker_1.9.2.ptf in /Firmware. Install it the same way, or put its file name into /Firmware/ot_restore.txt and power-cycle. Keep only the image you want, plus stock, in /Firmware: the rear reset button installs a random .ptf from that folder.

Note: projects saved by 2.0 use the Mini's 16-track patterns. Stock firmware for the original Tracker reads only tracks 1–8 of those patterns (expected from the stock loader's rules; not yet confirmed on a stock unit).

• The synth sound is own design: settings match the Mini, the sound is close but not identical.
• WTFM and FAT engines: planned for 2.1. Wavetable and granular samples play the left channel only (stereo in 2.1).
• The synth voice pool defaults to 4 because of the processor's speed.
• USB Storage mode: back up the card before first use; Linux systems without a desktop may need partprobe or a re-plug to see the card.
• The USB ID is the pid.codes test ID 1209:0001.

The package's Projects/ folder holds five OT Test songs and seven BLAST GRID synth remixes (Title, World 1, World 4, Battle, Battle FM, Boss, Final Boss). Copy them to /Projects on the card.

Downloads: https://github.com/sandlbn/polyend-tracker-re/releases