AxibugEmuOnline/Core/VirtualNes.Core/Mapper/Mapper026.cs

//////////////////////////////////////////////////////////////////////////
// Mapper026  Konami VRC6 (PA0,PA1 reverse)                             //
//////////////////////////////////////////////////////////////////////////
using System;
using static VirtualNes.Core.CPU;
using static VirtualNes.MMU;
using BYTE = System.Byte;
using INT = System.Int32;


namespace VirtualNes.Core
{
    public class Mapper026 : Mapper
    {

        BYTE irq_enable;
        BYTE irq_counter;
        BYTE irq_latch;
        INT irq_clock;
        public Mapper026(NES parent) : base(parent)
        {
        }


        public override void Reset()
        {
            irq_enable = 0;
            irq_counter = 0;
            irq_latch = 0;
            irq_clock = 0;

            SetPROM_32K_Bank(0, 1, PROM_8K_SIZE - 2, PROM_8K_SIZE - 1);

            if (VROM_1K_SIZE != 0)
            {
                SetVROM_8K_Bank(0);
            }

            uint crc = nes.rom.GetPROM_CRC();
            if (crc == 0x30e64d03)
            {   // Esper Dream 2 - Aratanaru Tatakai(J)
                nes.SetRenderMethod(EnumRenderMethod.POST_ALL_RENDER);
            }
            if (crc == 0x836cc1ab)
            {   // Mouryou Senki Madara(J)
                nes.SetRenderMethod(EnumRenderMethod.POST_ALL_RENDER);
            }
            nes.apu.SelectExSound(1);
        }

        //void Mapper026::Write(WORD addr, BYTE data)
        public override void Write(ushort addr, byte data)
        {
            switch (addr & 0xF003)
            {
                case 0x8000:
                    SetPROM_16K_Bank(4, data);
                    break;

                case 0x9000:
                case 0x9001:
                case 0x9002:
                case 0x9003:
                case 0xA000:
                case 0xA001:
                case 0xA002:
                case 0xA003:
                case 0xB000:
                case 0xB001:
                case 0xB002:
                    addr = (ushort)((addr & 0xfffc) | ((addr & 1) << 1) | ((addr & 2) >> 1));
                    nes.apu.ExWrite(addr, data);
                    break;

                case 0xB003:
                    data = (byte)(data & 0x7F);
                    if (data == 0x08 || data == 0x2C) SetVRAM_Mirror(VRAM_MIRROR4H);
                    else if (data == 0x20) SetVRAM_Mirror(VRAM_VMIRROR);
                    else if (data == 0x24) SetVRAM_Mirror(VRAM_HMIRROR);
                    else if (data == 0x28) SetVRAM_Mirror(VRAM_MIRROR4L);
                    break;

                case 0xC000:
                    SetPROM_8K_Bank(6, data);
                    break;

                case 0xD000:
                    SetVROM_1K_Bank(0, data);
                    break;

                case 0xD001:
                    SetVROM_1K_Bank(2, data);
                    break;

                case 0xD002:
                    SetVROM_1K_Bank(1, data);
                    break;

                case 0xD003:
                    SetVROM_1K_Bank(3, data);
                    break;

                case 0xE000:
                    SetVROM_1K_Bank(4, data);
                    break;

                case 0xE001:
                    SetVROM_1K_Bank(6, data);
                    break;

                case 0xE002:
                    SetVROM_1K_Bank(5, data);
                    break;

                case 0xE003:
                    SetVROM_1K_Bank(7, data);
                    break;

                case 0xF000:
                    irq_latch = data;
                    break;
                case 0xF001:
                    irq_enable = (byte)((irq_enable & 0x01) * 3);
                    nes.cpu.ClrIRQ(IRQ_MAPPER);
                    break;
                case 0xF002:
                    irq_enable = (byte)(data & 0x03);
                    if ((irq_enable & 0x02) != 0)
                    {
                        irq_counter = irq_latch;
                        irq_clock = 0;
                    }
                    nes.cpu.ClrIRQ(IRQ_MAPPER);
                    break;
            }
        }

        //void Mapper026::Clock(INT cycles)
        public override void Clock(int cycles)
        {
            if ((irq_enable & 0x02) != 0)
            {
                if ((irq_clock += cycles) >= 0x72)
                {
                    irq_clock -= 0x72;
                    if (irq_counter >= 0xFF)
                    {
                        irq_counter = irq_latch;
                        //				nes.cpu.IRQ_NotPending();
                        ////				nes.cpu.IRQ();
                        nes.cpu.SetIRQ(IRQ_MAPPER);
                    }
                    else
                    {
                        irq_counter++;
                    }
                }
            }
        }

        //void Mapper026::SaveState(LPBYTE p)
        public override void SaveState(byte[] p)
        {
            p[0] = irq_enable;
            p[1] = irq_counter;
            p[2] = irq_latch;
            //*(INT*)&p[3] = irq_clock;
            BitConverter.GetBytes(irq_clock).CopyTo(p, 3);
        }

        //void Mapper026::LoadState(LPBYTE p)
        public override void LoadState(byte[] p)
        {
            irq_enable = p[0];
            irq_counter = p[1];
            irq_latch = p[2];
            //irq_clock = *(INT*)&p[3];
            irq_clock = BitConverter.ToInt32(p, 3);
        }



        public override bool IsStateSave()
        {
            return true;
        }
    }
}