I don't have a PC Engine myself, but as I understand a hucard converter will work for you, but in addition you'll also need to lift and ground one of the pins on a chip inside the system. A quick search brought up this page which explains it clearly:
http://www.mmmonkey.co.uk/console/pce/region.htmThere is also a schematic for which hucard pins you need to flip on that same page, here:
http://www.mmmonkey.co.uk/console/images/pce/original.gifAt first I was thinking of seperating the ribbon cable and doing the flip there, but I thought that might lead to problems with the wires getting pulled on, or being a bit too short, so I cut the eight traces on the PCB just below the PCI slot and rewired it there.
As for the PCI slot, I widened it so that the edge of the hucard goes right up against the PCI slot's edge. So the first two pins of the PCI connector are not doing anything, the third pin is the first that makes contact, to pin 38 of the hucard in my case. This works out well because when cutting the bottom PCB, leaving two dummy pins on each side of the actual 38 hucard pins makes the PCB almost exactly the same width as the hucard. I'll post a picture of the slot with the hucard half-out so you can see how mine lines up.
Widening the PCI slot right against the side was a bit difficult since I couldn't really get my dremel down there without cutting through the slot's side, which I accidentally did a little. I ended up sort of chiseling that part out with a small screwdriver and a hammer.
