Files
player/Project/Src/NES/mapper/026.cpp
2025-06-27 00:32:57 +08:00

154 lines
2.4 KiB
C++

/////////////////////////////////////////////////////////////////////
// Mapper 26
void NES_mapper26::Reset()
{
// Init ExSound
parent_NES->apu->SelectExSound(1);
// set CPU bank pointers
set_CPU_banks(0,1,num_8k_ROM_banks-2,num_8k_ROM_banks-1);
// set PPU bank pointers
if(num_1k_VROM_banks)
{
set_PPU_banks(0,1,2,3,4,5,6,7);
}
irq_enabled = 0;
irq_counter = 0;
}
void NES_mapper26::MemoryWrite(uint32 addr, uint8 data)
{
switch(addr)
{
case 0x8000:
{
set_CPU_bank4(data*2+0);
set_CPU_bank5(data*2+1);
}
break;
case 0xB003:
{
data = data & 0x7F;
if(data == 0x08 || data == 0x2C)
{
set_mirroring(1,1,1,1);
}
else if(data == 0x20)
{
set_mirroring(NES_PPU::MIRROR_VERT);
}
else if(data == 0x24)
{
set_mirroring(NES_PPU::MIRROR_HORIZ);
}
else if(data == 0x28)
{
set_mirroring(0,0,0,0);
}
}
break;
case 0xC000:
{
set_CPU_bank6(data);
}
break;
case 0xD000:
{
set_PPU_bank0(data);
}
break;
case 0xD001:
{
set_PPU_bank2(data);
}
break;
case 0xD002:
{
set_PPU_bank1(data);
}
break;
case 0xD003:
{
set_PPU_bank3(data);
}
break;
case 0xE000:
{
set_PPU_bank4(data);
}
break;
case 0xE001:
{
set_PPU_bank6(data);
}
break;
case 0xE002:
{
set_PPU_bank5(data);
}
break;
case 0xE003:
{
set_PPU_bank7(data);
}
break;
case 0xF000:
{
irq_latch = data;
}
break;
case 0xF001:
{
irq_enabled = data & 0x01;
}
break;
case 0xF002:
{
irq_enabled = data & 0x03;
if(irq_enabled & 0x02)
{
irq_counter = irq_latch;
}
}
break;
}
addr = addr & 0xfffc | ((addr & 1) << 1) | ((addr & 2) >> 1);
parent_NES->apu->ExWrite(addr, data);
}
void NES_mapper26::HSync(uint32 scanline)
{
if(irq_enabled & 0x03)
{
if(irq_counter >= 0xFE)
{
parent_NES->cpu->DoIRQ();
irq_counter = irq_latch;
irq_enabled = 0;
}
else
{
irq_counter++;
}
}
}
/////////////////////////////////////////////////////////////////////