95 lines
1.9 KiB
C#
95 lines
1.9 KiB
C#
using System.IO;
|
|
|
|
namespace MyNes.Core
|
|
{
|
|
[BoardInfo("Mario Baby", 42)]
|
|
internal class Mapper042 : Board
|
|
{
|
|
private int SRAM_PRG_Page;
|
|
|
|
private bool irqEnable;
|
|
|
|
private int irqCounter;
|
|
|
|
internal override void HardReset()
|
|
{
|
|
base.HardReset();
|
|
Switch32KPRG(PRG_ROM_32KB_Mask, PRGArea.Area8000);
|
|
}
|
|
|
|
internal override void WritePRG(ref ushort address, ref byte data)
|
|
{
|
|
if (address == 32768)
|
|
{
|
|
Switch08KCHR(data);
|
|
return;
|
|
}
|
|
if (address == 61440)
|
|
{
|
|
SRAM_PRG_Page = data << 13;
|
|
return;
|
|
}
|
|
switch (address & 0xE003)
|
|
{
|
|
case 57344:
|
|
Switch08KPRG(data, PRGArea.Area6000);
|
|
break;
|
|
case 57345:
|
|
if ((data & 8) == 8)
|
|
{
|
|
Switch01KNMTFromMirroring(Mirroring.Horz);
|
|
}
|
|
else
|
|
{
|
|
Switch01KNMTFromMirroring(Mirroring.Vert);
|
|
}
|
|
break;
|
|
case 57346:
|
|
irqEnable = (data & 2) == 2;
|
|
if (!irqEnable)
|
|
{
|
|
irqCounter = 0;
|
|
}
|
|
NesEmu.IRQFlags &= -9;
|
|
break;
|
|
}
|
|
}
|
|
|
|
internal override void OnCPUClock()
|
|
{
|
|
if (!irqEnable)
|
|
{
|
|
return;
|
|
}
|
|
int num = irqCounter++;
|
|
if ((irqCounter & 0x6000) != (num & 0x6000))
|
|
{
|
|
if ((irqCounter & 0x6000) == 24576)
|
|
{
|
|
NesEmu.IRQFlags |= 8;
|
|
}
|
|
else
|
|
{
|
|
NesEmu.IRQFlags &= -9;
|
|
}
|
|
}
|
|
}
|
|
|
|
internal override void WriteStateData(ref BinaryWriter stream)
|
|
{
|
|
base.WriteStateData(ref stream);
|
|
stream.Write(SRAM_PRG_Page);
|
|
stream.Write(irqEnable);
|
|
stream.Write(irqCounter);
|
|
}
|
|
|
|
internal override void ReadStateData(ref BinaryReader stream)
|
|
{
|
|
base.ReadStateData(ref stream);
|
|
SRAM_PRG_Page = stream.ReadInt32();
|
|
irqEnable = stream.ReadBoolean();
|
|
irqCounter = stream.ReadInt32();
|
|
}
|
|
}
|
|
}
|