AxibugEmuOnline/OtherCore/MyNes.Standard2/MyNes.Core/Mapper050.cs

72 lines
1.6 KiB
C#

using System.IO;
namespace MyNes.Core
{
[BoardInfo("FDS-Port - Alt. Levels", 50)]
internal class Mapper050 : Board
{
private int prg_page;
private int irq_counter;
private bool irq_enabled;
internal override void HardReset()
{
base.HardReset();
Switch08KPRG(15, PRGArea.Area6000);
Switch08KPRG(8, PRGArea.Area8000);
Switch08KPRG(9, PRGArea.AreaA000);
Switch08KPRG(11, PRGArea.AreaE000);
}
internal override void WriteEX(ref ushort address, ref byte data)
{
switch (address & 0x4120)
{
case 16416:
prg_page = (data & 8) | ((data & 1) << 2) | ((data >> 1) & 3);
Switch08KPRG(prg_page, PRGArea.AreaC000);
break;
case 16672:
irq_enabled = (data & 1) == 1;
if (!irq_enabled)
{
irq_counter = 0;
NesEmu.IRQFlags &= -9;
}
break;
}
}
internal override void OnCPUClock()
{
if (irq_enabled)
{
irq_counter++;
if (irq_counter == 4096)
{
NesEmu.IRQFlags |= 8;
irq_counter = 0;
}
}
}
internal override void WriteStateData(ref BinaryWriter stream)
{
base.WriteStateData(ref stream);
stream.Write(prg_page);
stream.Write(irq_counter);
stream.Write(irq_enabled);
}
internal override void ReadStateData(ref BinaryReader stream)
{
base.ReadStateData(ref stream);
prg_page = stream.ReadInt32();
irq_counter = stream.ReadInt32();
irq_enabled = stream.ReadBoolean();
}
}
}