You can read more about it at http://www.spinpoint.org/cpc/m4info.txt and at https://www.spinpoint.org/2019/11/19/m4-board-guides/
<gallery>[[File:M4board_front.png|M4 Front View500px]] [[File:M4board_back.png|M4 Back View</gallery>500px]]
== Firmware ==