protected void WriteByte(uint addr, byte value)
{
bool even = (addr & 0x1) == 0;
if (addr < 0x8000)
{
if (_prgRAMEnabled)
{
_prgRAM[addr - 0x6000] = value;
}
}
else if (addr < 0xA000)
{
if (even)
{
_currentBank = value & 0x7u;
_prgBankingMode = (PRGBankingMode)((value >> 6) & 0x1);
_chrBankingMode = (CHRBankingMode)((value >> 7) & 0x1);
}
else
{
_banks[_currentBank] = value;
}
UpdateOffsets();
}
else if (addr < 0xC000)
{
if (even)
{
_emulator.Cartridge.MirroringMode = _mirroringModes[value & 0x1];
}
else
{
_prgRAMEnabled = (value & 0xC0) == 0x80;
}
}
else if (addr < 0xE000)
{
if (even)
{
_irqReloadValue = value;
}
else
{
_irqCounter = 0;
}
}
else
{
_irqEnabled = !even;
}
}
private void UpdateControl(uint value)
{
_control = value;
_emulator.Cartridge.MirroringMode = _mirroringModes[value & 0x3];
_chrBankingMode = (CHRBankingMode)((value >> 4) & 0x1);
var prgMode = (value >> 2) & 0x3;
// Both 0 and 1 are 32Kb switch
if (prgMode == 0)
{
prgMode = 1;
}
_prgBankingMode = (PRGBankingMode)(prgMode - 1);
UpdateCHRBank(1, _chrBanks[1]);
UpdateCHRBank(0, _chrBanks[0]);
UpdatePRGBank(_prgBank);
}
