I recycled my "Generic USB Linker" gizmo to make a Flash cart for PC Engine consoles.
I etched a PCB having roughly the size of a HuCard, and connected it to my flash board, and it works... almost. For some reason, on the ROM I've tested, some sprites are garbage, but the reamining sprites/backgrounds are OK, music and SFX work too, as well as the game itself. Weird. Well it's enough for today, I'll have a look at these issues later ;)

Here is a picture for now (click on it to get a full-sized one).