If a particular cartridge PCB has hard-wired mirroring that cannot be selected via solder pads or jumpers, should the hard-wiring be enforced in an emulator's mapper emulation code, or set via the iNES header?
The concrete example is Magic Kid GooGoo. The ROM image on Lost Levels is set to Horizontal Mirroring, even though the game needs Vertical Mirroring. FCEUX just hardcodes Vertical Mirroring right into the mapper emulation code. Initially, this seemed like a hacky solution to me for a mis-headered ROM using a singleton mapper. But then I wondered whether this should be considered correct for PCBs without solder pads. It would reflect the logic on that particular PCB, at the cost of losing flexibility if a second game with a similar PCB but different mirroring shows up.
(Edit: Added link to FCEUX source code.)
The concrete example is Magic Kid GooGoo. The ROM image on Lost Levels is set to Horizontal Mirroring, even though the game needs Vertical Mirroring. FCEUX just hardcodes Vertical Mirroring right into the mapper emulation code. Initially, this seemed like a hacky solution to me for a mis-headered ROM using a singleton mapper. But then I wondered whether this should be considered correct for PCBs without solder pads. It would reflect the logic on that particular PCB, at the cost of losing flexibility if a second game with a similar PCB but different mirroring shows up.
(Edit: Added link to FCEUX source code.)