AxibugEmuOnline/AxibugEmuOnline.Client/Assets/VirtualNes.Core/Mapper/Mapper006.cs

116 lines
3.2 KiB
C#

//////////////////////////////////////////////////////////////////////////
// Mapper006 FFE F4xxx //
//////////////////////////////////////////////////////////////////////////
using System;
using static VirtualNes.Core.CPU;
using static VirtualNes.MMU;
using BYTE = System.Byte;
using INT = System.Int32;
namespace VirtualNes.Core
{
public class Mapper006 : Mapper
{
BYTE irq_enable;
INT irq_counter;
public Mapper006(NES parent) : base(parent) { }
public override void Reset()
{
SetPROM_32K_Bank(0, 1, 14, 15);
if (VROM_1K_SIZE != 0)
{
SetVROM_8K_Bank(0);
}
else
{
SetCRAM_8K_Bank(0);
}
irq_enable = 0;
irq_counter = 0;
}
//void Mapper006::WriteLow(WORD addr, BYTE data)
public override void WriteLow(ushort addr, byte data)
{
switch (addr)
{
case 0x42FE:
if ((data & 0x10) != 0) SetVRAM_Mirror(VRAM_MIRROR4H);
else SetVRAM_Mirror(VRAM_MIRROR4L);
break;
case 0x42FF:
if ((data & 0x10) != 0) SetVRAM_Mirror(VRAM_HMIRROR);
else SetVRAM_Mirror(VRAM_VMIRROR);
break;
case 0x4501:
irq_enable = 0;
nes.cpu.ClrIRQ(IRQ_MAPPER);
break;
case 0x4502:
irq_counter = (irq_counter & 0xFF00) | data;
break;
case 0x4503:
irq_counter = (irq_counter & 0x00FF) | ((INT)data << 8);
irq_enable = 0xFF;
nes.cpu.ClrIRQ(IRQ_MAPPER);
break;
default:
base.WriteLow(addr, data);
break;
}
}
//void Mapper006::Write(WORD addr, BYTE data)
public override void Write(ushort addr, byte data)
{
SetPROM_16K_Bank(4, (data & 0x3C) >> 2);
SetCRAM_8K_Bank(data & 0x03);
}
//void Mapper006::HSync(INT scanline)
public override void HSync(int scanline)
{
if (irq_enable != 0)
{
irq_counter += 133;
if (irq_counter >= 0xFFFF)
{
// nes.cpu.IRQ();
irq_counter = 0;
nes.cpu.SetIRQ(IRQ_MAPPER);
}
}
}
//void Mapper006::SaveState(LPBYTE p)
public override void SaveState(byte[] p)
{
p[0] = irq_enable;
//*(INT*)&p[1] = irq_counter;
BitConverter.GetBytes(irq_counter).CopyTo(p, 1);
}
//void Mapper006::LoadState(LPBYTE p)
public override void LoadState(byte[] p)
{
irq_enable = p[0];
//irq_counter = *(INT*)&p[1];
irq_counter = BitConverter.ToInt32(p, 1);
}
public override bool IsStateSave()
{
return true;
}
}
}