From 5808f00555c48e1cc1cc110af6a5cd73ddf13010 Mon Sep 17 00:00:00 2001 From: Peter Fors Date: Fri, 2 May 2025 23:15:47 +0200 Subject: cleanup and rewrite of ppu_registers.c --- mappers/mapper_066_0.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 mappers/mapper_066_0.c (limited to 'mappers/mapper_066_0.c') diff --git a/mappers/mapper_066_0.c b/mappers/mapper_066_0.c new file mode 100644 index 0000000..bf31720 --- /dev/null +++ b/mappers/mapper_066_0.c @@ -0,0 +1,38 @@ + +static uint8_t mapper_066_0_prg_read(struct nes_state *state, uint32_t addr) { + struct mapper_066_0 *mapper = (struct mapper_066_0 *)&state->map; + + if(addr >= 0x8000) { + return state->prg_rom[addr & 0x7fff]; + } + return 0; +} + +static void mapper_066_0_prg_write(struct nes_state *state, uint32_t addr, uint8_t value) { + struct mapper_066_0 *mapper = (struct mapper_066_0 *)&state->map; + + if(addr >= 0x8000) { + uint32_t prg_bank = (value >> 4) & 3; + uint32_t chr_bank = (value >> 0) & 3; + + mapper->prg_offset = state->prg_rom + (prg_bank * 0x8000); + mapper->chr_offset = state->chr_rom + (chr_bank * 0x2000); + } +} + +static uint8_t mapper_066_0_chr_read(struct nes_state *state, uint32_t addr) { + struct mapper_066_0 *mapper = (struct mapper_066_0 *)&state->map; + return mapper->chr_offset[addr]; +} + +static void mapper_066_0_init(struct nes_state *state) { + struct mapper_066_0 *mapper = (struct mapper_066_0 *)&state->map; + + mapper->prg_offset = state->prg_rom; + mapper->chr_offset = state->chr_rom; + + state->mapper.prg_read = mapper_066_0_prg_read; + state->mapper.prg_write = mapper_066_0_prg_write; + state->mapper.chr_read = mapper_066_0_chr_read; +} + -- cgit v1.2.3