Here is some update.
I've been able to have the rom to boot on the cartridge in lorom mode.
But when it load it shows interface register, immmediate register and immediate rom error.
When I try to lunch the game, the capcom logo and intro music starts.. then nothing... I get black screen, then a purple screen .
Here is how I wired my stuff.
First I used a FPZ rom hack that I splitted into 2x16mb
2xam29f016b eeprom and retrostage fx adapter
the eeprom /ce lines are connected to a 139 decoder.
Decoder enabler is vss and inputs are A21 (cx4 pin15) ans vss
Last I connected both eeprom A20 directly to the cx4 RA20 (pin34).
Here is a picture of my working board
Sorry about the fuzzy wiring, its kind of a test board, so I needed to have quick access to /oe, /cs, vss and vcc


Is the issue with the romhack or my build?
I think we are really close to it, a bit of help would be appreciated
Hi man, i've just pass this same issue with a megaman x2+x3 multicart on a rockman x2 donor. i just change the oscilator cristal rmx2 uses a 20mhz a change do 21,4 mhz and worked. i don't know why, but worked.