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docs/engine_settings.md

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+# Settings
+
+The audio engine can be configured through the Engine page or via command-line arguments. Settings are saved and restored between sessions.
+
+## Engine Page
+
+Press `Ctrl+Right` until you reach the Engine page. Here you can see the engine status and adjust settings.
+
+### Display
+
+The right side of the page shows visualizations:
+
+- **Scope**: oscilloscope showing the audio waveform
+- **Spectrum**: 32-band frequency analyzer
+
+### Settings
+
+Navigate with arrow keys, adjust values with left/right:
+
+- **Output Device**: where sound goes (speakers, headphones, interface).
+- **Input Device**: what audio input source to use (microphone, line-in, etc.).
+- **Channels**: number of output channels (2 for stereo).
+- **Buffer Size**: audio buffer in samples (64-4096).
+- **Max Voices**: polyphony limit (1-128, default 32).
+- **Lookahead**: scheduling lookahead in milliseconds (0-50, default 15).
+
+### Buffer Size
+
+Smaller buffers mean lower latency but higher CPU load. Larger buffers are safer but feel sluggish.
+
+| Buffer | Latency at 44.1kHz |
+|--------|-------------------|
+| 64     | ~1.5ms            |
+| 128    | ~3ms              |
+| 256    | ~6ms              |
+| 512    | ~12ms             |
+| 1024   | ~23ms             |
+
+Start with 512. Lower it if you need tighter timing. Raise it if you hear glitches.
+
+### Samples
+
+The engine indexes audio files from your sample directories. Add directories with `A`, remove with `D`. The sample count shows how many files are indexed. You can load as many sample banks as you want, they are not really loaded into memory but _lazily loaded_. They are loaded on demand when you play a sample. Samples are referenced by filename without extension: 
+
+```forth
+kick s .       ;; plays kick.wav, kick.mp3, etc.
+```
+
+## Troubleshooting
+
+* **No sound**: Check output device selection.
+    * Try the test sound (`t`) on Engine page).
+
+* **Glitches/crackling**: Increase buffer size, restart the Engine.
+
+* **High CPU**: Reduce max voices. Disable scope/spectrum. Increase buffer size.
+
+* **Samples not found**: Check sample directories on Engine page. Filenames are case-sensitive on some systems.