static void mapper_0003_init(struct nes_state *state) { state->map.m0003.chr_ptr = state->chr_rom; } static uint8_t mapper_0003_prg_read(struct nes_state *state, uint32_t addr) { if(addr >= 0x8000) { return state->prg_rom[addr - 0x8000]; } return 0; } static void mapper_0003_prg_write(struct nes_state *state, uint32_t addr, uint8_t value) { if(addr >= 0x8000) { state->map.m0003.chr_ptr = state->chr_rom + (value & 3) * 0x2000; } } static uint8_t mapper_0003_chr_read(struct nes_state *state, uint32_t addr) { return state->map.m0003.chr_ptr[addr]; } static void mapper_0003_chr_write(struct nes_state *state, uint32_t addr, uint8_t value) { }