099.cpp

来自「PocketNester的c++源代码,很好的学习例子,仅供大家学习」· C++ 代码 · 共 43 行

/////////////////////////////////////////////////////////////////////
// Mapper 99
void NES_mapper99::Reset()
{
  // set CPU bank pointers
  if(num_8k_ROM_banks > 2)
  {
    set_CPU_banks(0,1,2,3);
  }
  else if(num_8k_ROM_banks > 1)
  {
    set_CPU_banks(0,1,0,1);
  }
  else
  {
    set_CPU_banks(0,0,0,0);
  }

  // set VROM bank
  if(num_1k_VROM_banks)
  {
    set_PPU_banks(0,1,2,3,4,5,6,7);
  }
}

void NES_mapper99::WriteHighRegs(uint32 addr, uint8 data)
{
  if(addr == 0x4016)
  {
    if(data & 0x04)
    {
      set_PPU_banks(8,9,10,11,12,13,14,15);
    }
    else
    {
      set_PPU_banks(0,1,2,3,4,5,6,7);
    }
  }
}
/////////////////////////////////////////////////////////////////////