static void mapper_001_init(struct nes_state *state) { // Nothing to initialize for 001 } static uint8_t mapper_001_prg_read(struct nes_state *state, uint32_t addr) { uint32_t prg_size = state->ines.prg_size; uint32_t mask = (state->ines.prg_size == 16384) ? 0x3fff : 0x7fff; return state->prg_rom[addr & mask]; } static void mapper_001_prg_write(struct nes_state *state, uint32_t addr, uint8_t value) { } static uint8_t mapper_001_chr_read(struct nes_state *state, uint32_t addr) { return state->chr_rom[addr]; } static void mapper_001_chr_write(struct nes_state *state, uint32_t addr, uint8_t value) { } static uint8_t mapper_001_ciram_read(struct nes_state *state, uint32_t addr) { if(state->ines.mirroring == 0) { // Horizontal addr = (addr & 0x800) | (addr & 0x3ff); } else { // Vertical (default fallback) addr = addr & 0x7ff; } return state->ciram[addr]; } static void mapper_001_ciram_write(struct nes_state *state, uint32_t addr, uint8_t value) { if(state->ines.mirroring == 0) { addr = (addr & 0x800) | (addr & 0x3ff); } else { addr = addr & 0x7ff; } state->ciram[addr] = value; } static void mapper_001_tick(struct nes_state *state) { }