So... Crop overscan does nothing when I set it in video settings.
However, there IS actually a first/last scanline in the emulator options, which allows you to essentially move the problem off screen. This seems a very "dirty" way to deal with it though (as I'm having to crop off some of the bottom few of the 240 lines).
From my understanding there wasn't any region protection for the CD based games and I remember trying some Japanese CDs in my TurboGrafx CD and TurboDuo about 10-15 years ago. I was surprised that they worked so well then!
I did some more research (or googling) and found a 3rd System Card v3.0 that is identified as being from Japan with an md5sum of 38179df8f4ac870017db21ebcbf53114. I tried Mirai Shounen Conan and Sylphia and they both worked on this BIOS. I also tried that 4 in 1 Super CD for the US Turbo Duo (this is the same one I had for my Duo which is also in storage lol) and it worked as well. The "System Card interface" looks just like ff1a674273fe3540ccef576376407d1d with "PC Engine" and "1991".
Also I was able to verify that the md5 of 0754f903b52e3b3342202bdafb13efa5 is indeed the USA version.
@Pyjamarama most games arent compatible with the six button controller and thats what happens. You need to play non six button controller games in 2 button mode. The only non cd games that use the six button controller are street fighter 2 and strip fighter 2.
Yes, what you put between <theme> and </theme> in /etc/emulationstation/es_systems.cfg refers to the corresponding directory in /etc/emulationstation/themes/<CURRENT THEME>/. There is also a theme.xml file in there that it uses to know what graphics to show.
nope putting the syscard3.pce in the directory as the cd images didnt help. havent found a program to convert a iso/wav/cue to a bin/cue yet, and as for the xbox controller issue, the pi recognises it, but a joystick test program doesnt read any inputs from it, its one of the newer xbox one controllers 16 something.