These links show the pinout: https://hardware.majix.org/computers/sgi/keyboards.shtml https://hardware.majix.org/computers/sgi/keyboards.shtml https://hardware

These links show the pinout: https://hardware.majix.org/computers/sgi/keyboards.shtml https://hardware.majix.org/computers/sgi/keyboards.shtml https://hardware.majix.org/computers/sgi.pi/keyboard.shtml https://hardware.majix.org/computers/sgi.pi/keyboard.shtml And the keyboard(7) man page actually has full details on the protocol (Indigo uses the mini DIN-6): https://github.com/jtsiomb/sgikbd/blob/master/doc/sgi_man7_keyboard https://github.com/jtsiomb/sgikbd/blob/master/doc/sgi_man7_k...