internal override void WriteRom(ushort address, byte value)
{
if (address <= 0x1FFF)
{
IsRamEnabled = (value & 0x0F) == 0x0A;
}
else if (address >= 0x2000 && address <= 0x2FFF)
{
_romb0 = value;
RomBank = ((_romb1 << 8) | _romb0) % ROMSize.NumberBanks();
}
else if (address >= 0x3000 && address <= 0x3FFF)
{
_romb1 = (byte)(value & 0b0000_0001); // Only bottom 1 bit is used AFAICT
RomBank = ((_romb1 << 8) | _romb0) % ROMSize.NumberBanks();
}
else if (address >= 0x4000 && address <= 0x5FFF)
{
if (RAMSize == CartridgeRAMSize.None)
{
RamBank = 0;
}
else
{
RamBank = (value & 8) % RAMSize.NumberBanks();
}
}
}
internal Cartridge(byte[] contents)
{
Contents = contents;
RamBanks = new byte[RAMSize.NumberBanks() * RAMSize.BankSizeBytes()];
RamBank = 0x0;
RomBank = 0x1;
IsRamEnabled = false;
}
internal override void WriteRom(ushort address, byte value)
{
if (address <= 0x1FFF)
{
IsRamEnabled = (value & 0x0F) == 0x0A;
}
else if (address >= 0x2000 && address <= 0x3FFF)
{
RomBank = (value & 0x7f) % ROMSize.NumberBanks();
if (RomBank == 0x0)
{
RomBank = 0x1;
}
}
else if (address >= 0x4000 && address < 0x5FFF)
{
if (value <= 0x3)
{
RamBank = value % RAMSize.NumberBanks();
_mappedRTCRegister = null;
}
else if (value >= 0x8 && value <= 0xC)
{
_mappedRTCRegister = value switch
{
0x8 => _rtcSecondsRegister,
0x9 => _rtcMinutesRegister,
0xA => _rtcHoursRegister,
0xB => _rtcLowBitsDayCounter,
0xC => _rtcHighBitsDayCounter,
_ => throw new ArgumentOutOfRangeException(nameof(value), value, $"Value {value} isn't mapped to an RTC register")
};
}
}
else if (address < 0x7FFF)
{
// Allow clock to start counting again
if (value == 0x1 && _latchedTime.HasValue)
{
_latchedTime = null;
}
// Latch current time
else if (value == 0x1)
{
_latchedTime = DateTime.UtcNow;
}
}
}