AxibugEmuOnline/AxibugEmuOnline.Client/Assets/VirtualNes.Core/Mapper/Mapper228.cs

//////////////////////////////////////////////////////////////////////////
// Mapper228  Action 52                                                 //
//////////////////////////////////////////////////////////////////////////
using static VirtualNes.MMU;
using BYTE = System.Byte;


namespace VirtualNes.Core
{
    public class Mapper228 : Mapper
    {
        public Mapper228(NES parent) : base(parent)
        {
        }

        public override void Reset()
        {
            SetPROM_32K_Bank(0);
            SetVROM_8K_Bank(0);
        }

        //void Mapper228::Write(WORD addr, BYTE data)
        public override void Write(ushort addr, byte data)
        {
            BYTE prg = (byte)((addr & 0x0780) >> 7);

            switch ((addr & 0x1800) >> 11)
            {
                case 1:
                    prg |= 0x10;
                    break;
                case 3:
                    prg |= 0x20;
                    break;
            }

            if ((addr & 0x0020) != 0)
            {
                prg <<= 1;
                if ((addr & 0x0040) != 0)
                {
                    prg++;
                }
                SetPROM_8K_Bank(4, prg * 4 + 0);
                SetPROM_8K_Bank(5, prg * 4 + 1);
                SetPROM_8K_Bank(6, prg * 4 + 0);
                SetPROM_8K_Bank(7, prg * 4 + 1);
            }
            else
            {
                SetPROM_8K_Bank(4, prg * 4 + 0);
                SetPROM_8K_Bank(5, prg * 4 + 1);
                SetPROM_8K_Bank(6, prg * 4 + 2);
                SetPROM_8K_Bank(7, prg * 4 + 3);
            }

            SetVROM_8K_Bank(((addr & 0x000F) << 2) | (data & 0x03));

            if ((addr & 0x2000) != 0)
            {
                SetVRAM_Mirror(VRAM_HMIRROR);
            }
            else
            {
                SetVRAM_Mirror(VRAM_VMIRROR);
            }
        }


    }
}