Mapper002B.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace BizHawk.Emulation.Cores.Computers.Commodore64.Cartridge
{
    // Prophet 64 cartridge. Because we can.
    // 32 banks of 8KB.
    // DFxx = status register, xxABBBBB. A=enable cart, B=bank
    // Thanks to VICE team for the info: http://vice-emu.sourceforge.net/vice_15.html

    public abstract partial class CartridgeDevice
    {
        private class Mapper002B : CartridgeDevice
        {
            [SaveState.DoNotSave]
            private readonly int[] _rom;
            [SaveState.SaveWithName("RomOffset")]
            private int _romOffset;
            [SaveState.SaveWithName("RomEnabled")]
            private bool _romEnabled;

            public Mapper002B(IList<int> newAddresses, IList<int> newBanks, IList<int[]> newData)
            {
                pinExRom = false;
                pinGame = true;
                _rom = new int[0x40000];
                Array.Copy(newData.First(), _rom, 0x2000);
                pinGame = true;
                for (var i = 0; i < newData.Count; i++)
                {
                    if (newAddresses[i] == 0x8000)
                    {
                        Array.Copy(newData[i], 0, _rom, newBanks[i] * 0x2000, 0x2000);
                    }
                }
            }

            public override void HardReset()
            {
                _romEnabled = true;
                _romOffset = 0;
            }

            public override int Peek8000(int addr)
            {
                return _romOffset | (addr & 0x1FFF);
            }

            public override int PeekDF00(int addr)
            {
                // For debugging only. The processor does not see this.
                return ((_romOffset >> 13) & 0x1F) | (_romEnabled ? 0x20 : 0x00);
            }

            public override void PokeDF00(int addr, int val)
            {
                _romOffset = (val & 0x1F) << 13;
                _romEnabled = (val & 0x20) != 0;
            }

            public override int Read8000(int addr)
            {
                return _romOffset | (addr & 0x1FFF);
            }

            public override int ReadDF00(int addr)
            {
                return 0x00;
            }

            public override void WriteDF00(int addr, int val)
            {
                _romOffset = (val & 0x1F) << 13;
                _romEnabled = (val & 0x20) != 0;
            }
        }
    }
}