Audio
Jack
- 3.5mm headset TRRS (stereo audio and microphone) connector with automatic switch to go from OMTP to CTIA as seen here
Volume Wheel
- Potentiometer (or rotary encoder?) connected to general-purpose input in SoC (allows software override of volume control)
Source: https://pyra-handheld.com/boards/threads/were-still-alive.77184/page-15#post-1372429
Microphone
- Microphone located at the left edge between keyboard and D-pad.
Speakers
- Stereo speakers in base with tuned cavity behind them as per manufacturers' recommendations.