diff options
Diffstat (limited to 'mapper_2002.c')
| -rw-r--r-- | mapper_2002.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/mapper_2002.c b/mapper_2002.c new file mode 100644 index 0000000..700a24b --- /dev/null +++ b/mapper_2002.c @@ -0,0 +1,28 @@ + +static void mapper_2002_init(struct nes_state *state) { + state->map.m2002.prg_bank0 = state->prg_rom; // default to bank 0 + state->map.m2002.prg_bank1 = state->prg_rom + state->ines.prg_size - 0x4000; +} + +static uint8_t mapper_2002_prg_read(struct nes_state *state, uint32_t addr) { + if(addr >= 0x8000 && addr < 0xc000) { + return state->map.m2002.prg_bank0[addr & 0x3fff]; + } else if(addr >= 0xc000) { + return state->map.m2002.prg_bank1[addr & 0x3fff]; + } + return 0; +} + +static void mapper_2002_prg_write(struct nes_state *state, uint32_t addr, uint8_t value) { + if(addr >= 0x8000) { + state->map.m2002.prg_bank0 = state->prg_rom + ((value & 0x0f) * 0x4000); + } +} + +static uint8_t mapper_2002_chr_read(struct nes_state *state, uint32_t addr) { + return state->chr_ram[addr]; +} + +static void mapper_2002_chr_write(struct nes_state *state, uint32_t addr, uint8_t value) { + state->chr_ram[addr] = value; +} |
