BizHawk/BizHawk.Emulation/Consoles/Sega/Genesis/MemoryMap.Z80.cs

61 lines
2.0 KiB
C#

using System;
namespace BizHawk.Emulation.Consoles.Sega
{
public partial class Genesis
{
private int BankRegion;
public byte ReadMemoryZ80(ushort address)
{
if (address < 0x4000)
{
//Console.WriteLine("read z80 memory {0:X4}: {1:X2}",address, Z80Ram[address & 0x1FFF]);
return Z80Ram[address & 0x1FFF];
}
if (address >= 0x4000 && address < 0x6000)
{
//Console.WriteLine(" === Z80 READS FM STATUS ===");
return YM2612.ReadStatus();
}
if (address >= 0x8000)
{
// 68000 Bank region
return (byte) ReadB(BankRegion | (address & 0x7FFF));
}
Console.WriteLine("UNHANDLED Z80 READ {0:X4}",address);
return 0xCD;
}
public void WriteMemoryZ80(ushort address, byte value)
{
if (address < 0x4000)
{
//Console.WriteLine("write z80 memory {0:X4}: {1:X2}",address, value);
Z80Ram[address & 0x1FFF] = value;
return;
}
if (address >= 0x4000 && address < 0x6000)
{
//Console.WriteLine(" === Z80 WRITES Z80 {0:X4}:{1:X2} ===",address, value);
YM2612.Write(address & 3, value);
return;
}
if (address == 0x6000)
{
BankRegion >>= 1;
BankRegion |= (value & 1) << 23;
BankRegion &= 0x00FF8000;
Console.WriteLine("Bank pointing at {0:X8}",BankRegion);
return;
}
if (address >= 0x8000)
{
WriteB(BankRegion | (address & 0x7FFF), (sbyte) value);
return;
}
Console.WriteLine("UNHANDLED Z80 WRITE {0:X4}:{1:X2}", address, value);
}
}
}