Mini PCI was designed for peripherals such as network adapters in laptops, but also wound up in DVD players, HDTVs and other devices. Type I and II cards have 100 pins, while Type III has 124.

It’s actually a fairly straightforward hack. The Mini PCI-e standard has a couple of pins dedicated to USB data lines, which the modem in question uses for communicating with the host computer.

There’s also four mini-PCI-E slots along the top ... Naturally, the Seaberry also features the usual 40-pin GPIO header, the 14-pin CM4 IO header, as well as the usual DSI, CSI and RTC hookups.