PAS16 - patch panel
The 15 pin port at the top is for connection of a PC joystick. The PAS16 drivers allowed the joystick to emulate the mouse.
There are three connectors arranged triangularly. The black one at the top is for headphones. The other two are stereo out. To the right of these is MIDI in and MIDI out. Below these are two row of four connectors. These are four channels of stereo in. In the bottom right is the microphone in.