Mapper 340 appears to be a very simple multi-cart mapper. The implementation in NintendulatorNRS matches the description in the wiki. And I attempted a similar implementation in my emulator. However, I found several of the games do not function in my implementation. Contra, Life Force, Rushn Attack and Galaxian all work fine. But the remainder has garbled graphics (wrong tiles). Some of those are playable and some of them crash on start up (KIL instructions encountered).
I checked over my implementation several times and I can't locate a bug. Interestingly, I noticed that the initial RAM state affects which games work. What does NintendulatorNRS set RAM to on startup? Maybe it's expecting some initial value set.
I checked over my implementation several times and I can't locate a bug. Interestingly, I noticed that the initial RAM state affects which games work. What does NintendulatorNRS set RAM to on startup? Maybe it's expecting some initial value set.