/
NesMemory.cs
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/
NesMemory.cs
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using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Emu6502
{
// TODO: Separate mapper system
public class NesMemory : IMemory
{
public byte[] RAM;
public byte[] SaveRAM;
private Nes nes;
private Rom rom;
public NesMemory(Nes nes)
{
this.nes = nes;
this.rom = nes.Rom;
}
public void Reset()
{
RAM = new byte[2048];
SaveRAM = new byte[0x2000];
}
public byte Read(int addr)
{
//addr = addr & 0xFFFF;
//Console.WriteLine("Read ${0:X4}", addr);
switch(addr & 0xF000)
{
case 0x0000:
case 0x1000:
//Console.WriteLine(" -> RAM ${0:X4} = ${1:X2}", addr, RAM[addr]);
return RAM[addr & 0x7FF];
case 0x2000:
case 0x3000:
{
Nes.ActiveNes.RecordEvent(String.Format("Mem.IO.${0:X4}.Read", addr));
addr = 0x2000 | (addr & 0x7);
byte b;
switch (addr)
{
case 0x2002:
b = nes.Ppu.ReadPpuStatus();
break;
case 0x2004:
b = nes.Ppu.ReadOAMData();
break;
case 0x2007:
b = nes.Ppu.ReadPpuData();
break;
default:
b = 0x0;
break;
}
/*if (addr != 0x2002)
Console.WriteLine("R IO ${0:X4} = ${1:X2}", addr, b);*/
return b;
}
// APU registers & expansion ROM (what the heck is that?)
case 0x4000:
case 0x5000:
{
Nes.ActiveNes.RecordEvent(String.Format("Mem.IO.${0:X4}.Read", addr));
byte b = 0;
if (addr == 0x4016)
{
//Console.WriteLine("Controller1 = {0:X}", nes.Controller1.Captured);
b = (byte)(nes.Controller1.Captured & 0x1);
nes.Controller1.Captured >>= 1;
}
else if (addr == 0x4017)
{
b = (byte)(nes.Controller2.Captured & 0x1);
nes.Controller2.Captured >>= 1;
}
else
if(addr <= 0x4020)
Console.WriteLine("R IO ${0:X4}", addr);
//Console.WriteLine("R IO ${0:X4} = ${1:X2}", addr, b);
/*if (addr < 0x4020)
{
//Console.WriteLine("R IO ${0:X4}", addr);
}*/
return b;
}
case 0x6000:
case 0x7000:
// TODO: Mirroring? Mapper specific?
Nes.ActiveNes.RecordEvent("Mem.SaveRam.Read");
return SaveRAM[addr & 0x1FFF];
case 0x8000:
case 0x9000:
case 0xA000:
case 0xB000:
case 0xC000:
case 0xD000:
case 0xE000:
case 0xF000:
return nes.Mapper.PrgRomRead(addr & 0xFFFF);
/*return rom.PrgRomBanks[0][addr & 0x3FFF];
return rom.PrgRomBanks[1][addr & 0x3FFF];*/
// Shut up, C# compiler
default:
return 0;
}
}
public void Write(int addr, byte val)
{
addr = addr & 0xFFFF;
//Console.WriteLine("Write ${0:X4} = ${1:X2}", addr, val);
if (addr < 0x2000)
{
// RAM mirroring
addr = addr & 0x7FF;
//Console.WriteLine(" -> RAM ${0:X4}", addr);
//Console.WriteLine("W RAM ${0:X4} = ${1:X2}", addr, val);
RAM[addr] = val;
}
else if (addr < 0x4000)
{
addr = 0x2000 | (addr & 0x7);
Nes.ActiveNes.RecordEvent(String.Format("Mem.IO.${0:X4}.Write", addr));
/*if (addr != 0x2003)
Console.WriteLine("W IO ${0:X4} = ${1:X2}", addr, val);*/
//Console.WriteLine("W IO ${0:X4} = ${1:X2}", addr, val);
switch (addr)
{
case 0x2000:
nes.Ppu.WritePpuCtrl(val);
break;
case 0x2001:
nes.Ppu.WritePpuMask(val);
break;
case 0x2003:
nes.Ppu.WriteOAMAddr(val);
break;
case 0x2004:
nes.Ppu.WriteOAMData(val);
break;
case 0x2005:
nes.Ppu.WritePpuScroll(val);
break;
case 0x2006:
nes.Ppu.WritePpuAddr(val);
break;
case 0x2007:
nes.Ppu.WritePpuData(val);
break;
default:
break;
}
}
else if (addr < 0x4020)
{
//Console.WriteLine("W IO ${0:X4} = ${1:X2}", addr, val);
Nes.ActiveNes.RecordEvent(String.Format("Mem.IO.${0:X4}.Write", addr));
// Fake DMA
if (addr == 0x4014)
{
ushort srcAddr = (ushort)(val * 0x100);
//Console.WriteLine("W IO $4014: DMAing ${0:X4} to OAM memory", srcAddr);
// TODO: LOL, potential explosion
for (int i = 0; i < 256; ++i)
{
byte b = Read(srcAddr + i);
nes.Ppu.SpriteMem[nes.Ppu.OAMAddr++] = b;
}
}
else if (addr == 0x4016)
{
if ((val & 0x1) != 0)
{
nes.Controller1.Capture();
nes.Controller2.Capture();
}
}
/*else
Console.WriteLine("W IO ${0:X4} = ${1:X2}", addr, val);*/
// TODO
}
else if (addr < 0x6000)
{
Nes.ActiveNes.RecordEvent("Mem.ExpansionROM.Write");
//Console.WriteLine(" -> Expansion ROM ${0:X4} = ${0:X2}", addr, val);
}
else if (addr < 0x8000)
{
Nes.ActiveNes.RecordEvent("Mem.SaveRam.Write");
SaveRAM[addr & 0x1FFF] = val;
//Console.WriteLine(" -> Save RAM ${0:X4} = ${0:X2}", addr, val);
// TODO
}
else
{
Nes.ActiveNes.RecordEvent("Mem.PrgRom.Write");
nes.Mapper.PrgRomWrite(addr, val);
//Console.WriteLine(" -> PRG-ROM ${0:X4} = ${0:X2}", addr, val);
}
}
}
}