BizHawk/BizHawk.Emulation.Cores/Consoles/PC Engine/MemoryMap.Populous.cs

64 lines
2.4 KiB
C#

using BizHawk.Common;
namespace BizHawk.Emulation.Cores.PCEngine
{
public partial class PCEngine
{
// The Populous HuCard is the only traditional HuCard to have battery-backed saveRAM
// built into it. There is 32k of save-RAM mapped at pages $40 - $44.
byte[] PopulousRAM;
byte ReadMemoryPopulous(int addr)
{
if (addr >= 0x80000 && addr < 0x88000)
return PopulousRAM[addr & 0x7FFF];
if (addr < 0xFFFFF) // read ROM
return RomData[addr % RomLength];
if (addr >= 0x1F0000 && addr < 0x1F8000) // read RAM
return Ram[addr & 0x1FFF];
if (addr >= 0x1FE000) // hardware page.
{
if (addr < 0x1FE400) return VDC1.ReadVDC(addr);
if (addr < 0x1FE800) { Cpu.PendingCycles--; return VCE.ReadVCE(addr); }
if (addr < 0x1FEC00) return IOBuffer;
if (addr < 0x1FF000) { IOBuffer = (byte)(Cpu.ReadTimerValue() | (IOBuffer & 0x80)); return IOBuffer; }
if (addr >= 0x1FF000 &&
addr < 0x1FF400) { IOBuffer = ReadInput(); return IOBuffer; }
if ((addr & ~1) == 0x1FF400) return IOBuffer;
if (addr == 0x1FF402) { IOBuffer = Cpu.IRQControlByte; return IOBuffer; }
if (addr == 0x1FF403) { IOBuffer = (byte)(Cpu.ReadIrqStatus() | (IOBuffer & 0xF8)); return IOBuffer; }
}
Log.Error("MEM", "UNHANDLED READ: {0:X6}", addr);
return 0xFF;
}
void WriteMemoryPopulous(int addr, byte value)
{
if (addr >= 0x1F0000 && addr < 0x1F8000) // write RAM.
Ram[addr & 0x1FFF] = value;
else if (addr >= 0x1FE000) // hardware page.
{
if (addr < 0x1FE400) VDC1.WriteVDC(addr, value);
else if (addr < 0x1FE800) { Cpu.PendingCycles--; VCE.WriteVCE(addr, value); }
else if (addr < 0x1FEC00) { IOBuffer = value; PSG.WritePSG((byte)addr, value, Cpu.TotalExecutedCycles); }
else if (addr == 0x1FEC00) { IOBuffer = value; Cpu.WriteTimer(value); }
else if (addr == 0x1FEC01) { IOBuffer = value; Cpu.WriteTimerEnable(value); }
else if (addr >= 0x1FF000 &&
addr < 0x1FF400) { IOBuffer = value; WriteInput(value); }
else if (addr == 0x1FF402) { IOBuffer = value; Cpu.WriteIrqControl(value); }
else if (addr == 0x1FF403) { IOBuffer = value; Cpu.WriteIrqStatus(); }
else Log.Error("MEM", "unhandled hardware write [{0:X6}] : {1:X2}", addr, value);
}
else if (addr >= 0x80000 && addr < 0x88000)
PopulousRAM[addr & 0x7FFF] = value;
else
Log.Error("MEM", "UNHANDLED WRITE: {0:X6}:{1:X2}", addr, value);
}
}
}