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player/Project/Src/NES/mapper/068.cpp

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2025-06-27 00:32:57 +08:00
/////////////////////////////////////////////////////////////////////
// Mapper 68
void NES_mapper68::Reset()
{
// set CPU bank pointers
set_CPU_banks(0,1,num_8k_ROM_banks-2,num_8k_ROM_banks-1);
regs[0] = 0;
regs[1] = 0;
regs[2] = 0;
regs[3] = 0;
}
void NES_mapper68::MemoryWrite(uint32 addr, uint8 data)
{
switch(addr & 0xF000)
{
case 0x8000:
{
set_PPU_bank0(data*2+0);
set_PPU_bank1(data*2+1);
}
break;
case 0x9000:
{
set_PPU_bank2(data*2+0);
set_PPU_bank3(data*2+1);
}
break;
case 0xA000:
{
set_PPU_bank4(data*2+0);
set_PPU_bank5(data*2+1);
}
break;
case 0xB000:
{
set_PPU_bank6(data*2+0);
set_PPU_bank7(data*2+1);
}
break;
case 0xC000:
{
regs[2] = data;
SyncMirror();
}
break;
case 0xD000:
{
regs[3] = data;
SyncMirror();
}
break;
case 0xE000:
{
regs[0] = (data & 0x10) >> 4;
regs[1] = data & 0x03;
SyncMirror();
}
break;
case 0xF000:
{
set_CPU_bank4(data*2);
set_CPU_bank5(data*2+1);
}
break;
}
}
void NES_mapper68::SyncMirror()
{
if(regs[0])
{
if (regs[1] == 0)
{
set_PPU_bank8(regs[2] + 0x80); // + 0x20000
set_PPU_bank9(regs[3] + 0x80);
set_PPU_bank10(regs[2] + 0x80);
set_PPU_bank11(regs[3] + 0x80);
}
else if (regs[1] == 1)
{
set_PPU_bank8(regs[2] + 0x80);
set_PPU_bank9(regs[2] + 0x80);
set_PPU_bank10(regs[3] + 0x80);
set_PPU_bank11(regs[3] + 0x80);
}
else if (regs[1] == 2)
{
set_PPU_bank8(regs[2] + 0x80);
set_PPU_bank9(regs[2] + 0x80);
set_PPU_bank10(regs[2] + 0x80);
set_PPU_bank11(regs[2] + 0x80);
}
else if (regs[1] == 3)
{
set_PPU_bank8(regs[3] + 0x80);
set_PPU_bank9(regs[3] + 0x80);
set_PPU_bank10(regs[3] + 0x80);
set_PPU_bank11(regs[3] + 0x80);
}
}
else
{
if (regs[1] == 0)
{
set_mirroring(NES_PPU::MIRROR_VERT);
}
else if (regs[1] == 1)
{
set_mirroring(NES_PPU::MIRROR_HORIZ);
}
else if (regs[1] == 2)
{
set_mirroring(0,0,0,0);
}
else if (regs[1] == 3)
{
set_mirroring(1,1,1,1);
}
}
}
/////////////////////////////////////////////////////////////////////