Files
player/Project/Src/NES/mapper/049.cpp
2025-06-27 00:32:57 +08:00

267 lines
5.7 KiB
C++

/////////////////////////////////////////////////////////////////////
// Mapper 49
void NES_mapper49::Reset()
{
// set CPU bank pointers
prg0 = 0;
prg1 = 1;
set_CPU_banks(0,1,2,3);
// set VROM banks
chr01 = 0;
chr23 = 2;
chr4 = 4;
chr5 = 5;
chr6 = 6;
chr7 = 7;
set_PPU_banks(0,1,2,3,4,5,6,7);
regs[0] = regs[1] = regs[2] = 0;
irq_enabled = 0;
irq_counter = 0;
irq_latch = 0;
}
void NES_mapper49::MemoryWriteSaveRAM(uint32 addr, uint8 data)
{
if(regs[2] & 0x80)
{
regs[1] = data;
MMC3_set_CPU_banks();
MMC3_set_PPU_banks();
}
}
void NES_mapper49::MemoryWrite(uint32 addr, uint8 data)
{
switch(addr & 0xE001)
{
case 0x8000:
{
if((data & 0x40) != (regs[0] & 0x40))
{
MMC3_set_CPU_banks();
}
if((data & 0x80) != (regs[0] & 0x80))
{
regs[0] = data;
MMC3_set_PPU_banks();
}
regs[0] = data;
}
break;
case 0x8001:
{
switch(regs[0] & 0x07)
{
case 0x00:
{
chr01 = data & 0xFE;
MMC3_set_PPU_banks();
}
break;
case 0x01:
{
chr23 = data & 0xFE;
MMC3_set_PPU_banks();
}
break;
case 0x02:
{
chr4 = data;
MMC3_set_PPU_banks();
}
break;
case 0x03:
{
chr5 = data;
MMC3_set_PPU_banks();
}
break;
case 0x04:
{
chr6 = data;
MMC3_set_PPU_banks();
}
break;
case 0x05:
{
chr7 = data;
MMC3_set_PPU_banks();
}
break;
case 0x06:
{
prg0 = data;
MMC3_set_CPU_banks();
}
break;
case 0x07:
{
prg1 = data;
MMC3_set_CPU_banks();
}
break;
}
}
break;
case 0xA000:
{
if(parent_NES->ROM->get_mirroring() != NES_PPU::MIRROR_FOUR_SCREEN)
{
if(data & 0x01)
{
set_mirroring(NES_PPU::MIRROR_HORIZ);
}
else
{
set_mirroring(NES_PPU::MIRROR_VERT);
}
}
}
break;
case 0xA001:
{
regs[2] = data;
}
break;
case 0xC000:
{
irq_counter = data;
}
break;
case 0xC001:
{
irq_latch = data;
}
break;
case 0xE000:
{
irq_enabled = 0;
}
break;
case 0xE001:
{
irq_enabled = 1;
}
break;
}
}
void NES_mapper49::HSync(uint32 scanline)
{
if(irq_enabled)
{
if((scanline >= 0) && (scanline <= 239))
{
if(parent_NES->ppu->spr_enabled() || parent_NES->ppu->bg_enabled())
{
if(!(irq_counter--))
{
irq_counter = irq_latch;
parent_NES->cpu->DoIRQ();
}
}
}
}
}
void NES_mapper49::MMC3_set_CPU_banks()
{
if(regs[1] & 0x01)
{
if(regs[0] & 0x40)
{
set_CPU_bank4(((num_8k_ROM_banks - 1) & 0xE) | ((regs[1] & 0xC0) >> 2));
set_CPU_bank5((prg1 & 0x0F) | ((regs[1] & 0xC0) >> 2));
set_CPU_bank6((prg0 & 0x0F) | ((regs[1] & 0xC0) >> 2));
set_CPU_bank7(((num_8k_ROM_banks - 1) & 0xF) | ((regs[1] & 0xC0) >> 2));
}
else
{
set_CPU_bank4((prg0 & 0x0F) | ((regs[1] & 0xC0) >> 2));
set_CPU_bank5((prg1 & 0x0F) | ((regs[1] & 0xC0) >> 2));
set_CPU_bank6(((num_8k_ROM_banks - 1) & 0xE) | ((regs[1] & 0xC0) >> 2));
set_CPU_bank7(((num_8k_ROM_banks - 1) & 0xF) | ((regs[1] & 0xC0) >> 2));
}
}
else
{
set_CPU_bank4(((regs[1] & 0x70) >> 2) | 0);
set_CPU_bank5(((regs[1] & 0x70) >> 2) | 1);
set_CPU_bank6(((regs[1] & 0x70) >> 2) | 2);
set_CPU_bank7(((regs[1] & 0x70) >> 2) | 3);
}
}
void NES_mapper49::MMC3_set_PPU_banks()
{
chr01 = (chr01 & 0x7F) | ((regs[1] & 0xC0) << 1);
chr23 = (chr23 & 0x7F) | ((regs[1] & 0xC0) << 1);
chr4 = (chr4 & 0x7F) | ((regs[1] & 0xC0) << 1);
chr5 = (chr5 & 0x7F) | ((regs[1] & 0xC0) << 1);
chr6 = (chr6 & 0x7F) | ((regs[1] & 0xC0) << 1);
chr7 = (chr7 & 0x7F) | ((regs[1] & 0xC0) << 1);
if(regs[0] & 0x80)
{
set_PPU_banks(chr4,chr5,chr6,chr7,chr01,chr01+1,chr23,chr23+1);
}
else
{
set_PPU_banks(chr01,chr01+1,chr23,chr23+1,chr4,chr5,chr6,chr7);
}
}
#define MAP49_ROM(ptr) (((ptr)-parent_NES->ROM->get_ROM_banks()) >> 13)
#define MAP49_VROM(ptr) (((ptr)-parent_NES->ROM->get_VROM_banks()) >> 10)
void NES_mapper49::SNSS_fixup()
{
NES_6502::Context context;
parent_NES->cpu->GetContext(&context);
if(regs[1])
{
prg0 = MAP49_ROM(context.mem_page[(regs[0] & 0x40) ? 6 : 4]);
prg1 = MAP49_ROM(context.mem_page[5]);
}
if(regs[0] & 0x80)
{
chr01 = MAP49_VROM(parent_NES->ppu->PPU_VRAM_banks[4]);
chr23 = MAP49_VROM(parent_NES->ppu->PPU_VRAM_banks[6]);
chr4 = MAP49_VROM(parent_NES->ppu->PPU_VRAM_banks[0]);
chr5 = MAP49_VROM(parent_NES->ppu->PPU_VRAM_banks[1]);
chr6 = MAP49_VROM(parent_NES->ppu->PPU_VRAM_banks[2]);
chr7 = MAP49_VROM(parent_NES->ppu->PPU_VRAM_banks[3]);
}
else
{
chr01 = MAP49_VROM(parent_NES->ppu->PPU_VRAM_banks[0]);
chr23 = MAP49_VROM(parent_NES->ppu->PPU_VRAM_banks[2]);
chr4 = MAP49_VROM(parent_NES->ppu->PPU_VRAM_banks[4]);
chr5 = MAP49_VROM(parent_NES->ppu->PPU_VRAM_banks[5]);
chr6 = MAP49_VROM(parent_NES->ppu->PPU_VRAM_banks[6]);
chr7 = MAP49_VROM(parent_NES->ppu->PPU_VRAM_banks[7]);
}
}
/////////////////////////////////////////////////////////////////////