94 lines
2.6 KiB
C#
94 lines
2.6 KiB
C#
//////////////////////////////////////////////////////////////////////////
|
|
// Mapper073 Konami VRC3 //
|
|
//////////////////////////////////////////////////////////////////////////
|
|
using static VirtualNes.Core.CPU;
|
|
using static VirtualNes.MMU;
|
|
using BYTE = System.Byte;
|
|
using INT = System.Int32;
|
|
|
|
|
|
namespace VirtualNes.Core
|
|
{
|
|
public class Mapper073 : Mapper
|
|
{
|
|
BYTE irq_enable;
|
|
INT irq_counter;
|
|
public Mapper073(NES parent) : base(parent)
|
|
{
|
|
}
|
|
|
|
public override void Reset()
|
|
{
|
|
irq_enable = 0;
|
|
irq_counter = 0;
|
|
|
|
SetPROM_32K_Bank(0, 1, PROM_8K_SIZE - 2, PROM_8K_SIZE - 1);
|
|
}
|
|
|
|
//void Mapper073::Write(WORD addr, BYTE data)
|
|
public override void Write(ushort addr, byte data)
|
|
{
|
|
switch (addr)
|
|
{
|
|
case 0xF000:
|
|
SetPROM_16K_Bank(4, data);
|
|
break;
|
|
|
|
case 0x8000:
|
|
irq_counter = (irq_counter & 0xFFF0) | (data & 0x0F);
|
|
break;
|
|
case 0x9000:
|
|
irq_counter = (irq_counter & 0xFF0F) | ((data & 0x0F) << 4);
|
|
break;
|
|
case 0xA000:
|
|
irq_counter = (irq_counter & 0xF0FF) | ((data & 0x0F) << 8);
|
|
break;
|
|
case 0xB000:
|
|
irq_counter = (irq_counter & 0x0FFF) | ((data & 0x0F) << 12);
|
|
break;
|
|
case 0xC000:
|
|
irq_enable = (byte)(data & 0x02);
|
|
nes.cpu.ClrIRQ(IRQ_MAPPER);
|
|
break;
|
|
case 0xD000:
|
|
nes.cpu.ClrIRQ(IRQ_MAPPER);
|
|
break;
|
|
}
|
|
}
|
|
|
|
//void Mapper073::Clock(INT cycles)
|
|
public override void Clock(int cycles)
|
|
{
|
|
if (irq_enable != 0)
|
|
{
|
|
if ((irq_counter += cycles) >= 0xFFFF)
|
|
{
|
|
irq_enable = 0;
|
|
irq_counter &= 0xFFFF;
|
|
nes.cpu.SetIRQ(IRQ_MAPPER);
|
|
}
|
|
}
|
|
}
|
|
|
|
//void Mapper073::SaveState(LPBYTE p)
|
|
public override void SaveState(byte[] p)
|
|
{
|
|
//p[0] = irq_enable;
|
|
//*(INT*)&p[1] = irq_counter;
|
|
}
|
|
|
|
//void Mapper073::LoadState(LPBYTE p)
|
|
public override void LoadState(byte[] p)
|
|
{
|
|
//irq_enable = p[0];
|
|
//irq_counter = *(INT*)&p[1];
|
|
}
|
|
|
|
public override bool IsStateSave()
|
|
{
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
|