Files
player/Project/Src/NES/mapper/091.cpp
2025-06-27 00:32:57 +08:00

100 lines
1.7 KiB
C++

/////////////////////////////////////////////////////////////////////
// Mapper 91
void NES_mapper91::Reset()
{
// set CPU bank pointers
set_CPU_bank4(num_8k_ROM_banks-2);
set_CPU_bank5(num_8k_ROM_banks-1);
set_CPU_bank6(num_8k_ROM_banks-2);
set_CPU_bank7(num_8k_ROM_banks-1);
// set PPU bank pointers
if(num_1k_VROM_banks)
{
set_PPU_banks(0,0,0,0,0,0,0,0);
}
}
void NES_mapper91::MemoryWriteSaveRAM(uint32 addr, uint8 data)
{
switch(addr & 0xF00F)
{
case 0x6000:
{
set_PPU_bank0(data*2+0);
set_PPU_bank1(data*2+1);
}
break;
case 0x6001:
{
set_PPU_bank2(data*2+0);
set_PPU_bank3(data*2+1);
}
break;
case 0x6002:
{
set_PPU_bank4(data*2+0);
set_PPU_bank5(data*2+1);
}
break;
case 0x6003:
{
set_PPU_bank6(data*2+0);
set_PPU_bank7(data*2+1);
}
break;
case 0x7000:
{
set_CPU_bank4(data);
}
break;
case 0x7001:
{
set_CPU_bank5(data);
}
break;
case 0x7002:
{
irq_counter = data;
}
break;
case 0x7003:
{
irq_enabled = data;
}
break;
}
}
void NES_mapper91::HSync(uint32 scanline)
{
if(irq_enabled)
{
if(0 <= scanline && scanline <= 240)
{
if(parent_NES->ppu->spr_enabled() || parent_NES->ppu->bg_enabled())
{
if(!irq_counter)
{
irq_enabled = 0;
parent_NES->cpu->DoIRQ();
}
else
{
irq_counter--;
}
}
}
}
}
/////////////////////////////////////////////////////////////////////