Cart7832P.cs

namespace EMU7800.Core
{
    /// <summary>
    /// Atari 7800 non-bankswitched 32KB cartridge w/Pokey
    /// </summary>
    public sealed class Cart7832P : Cart
    {
        //
        // Cart Format                Mapping to ROM Address Space
        //                            0x4000:0x4000 Pokey
        // 0x0000:0x8000              0x8000:0x8000
        //
        PokeySound _pokeySound;

        #region IDevice Members

        public override void Reset()
        {
            base.Reset();
            if (_pokeySound != null)
                _pokeySound.Reset();
        }

        public override byte this[ushort addr]
        {
            get
            {
                return ((addr & 0xF000) == 0x4000 && _pokeySound != null) ? _pokeySound.Read(addr) : ROM[addr & 0x7fff];
            }
            set
            {
                if ((addr & 0xF000) == 0x4000 && _pokeySound != null)
                    _pokeySound.Update(addr, value);
            }
        }

        #endregion

        public override void Attach(MachineBase m)
        {
            base.Attach(m);
            if (_pokeySound == null)
                _pokeySound = new PokeySound(M);
        }

        public override void StartFrame()
        {
            if (_pokeySound != null)
                _pokeySound.StartFrame();
        }

        public override void EndFrame()
        {
            if (_pokeySound != null)
                _pokeySound.EndFrame();
        }

        private Cart7832P()
        {
        }

        public Cart7832P(byte[] romBytes)
        {
            LoadRom(romBytes, 0x8000);
        }

        #region Serialization Members

        public Cart7832P(DeserializationContext input, MachineBase m) : base(input)
        {
            input.CheckVersion(1);
            LoadRom(input.ReadExpectedBytes(0x8000), 0x8000);
            _pokeySound = input.ReadOptionalPokeySound(m);
        }

        public override void GetObjectData(SerializationContext output)
        {
            if (_pokeySound == null)
                throw new Emu7800SerializationException("Cart7832P must be attached before serialization.");

            base.GetObjectData(output);

            output.WriteVersion(1);
            output.Write(ROM);
            output.WriteOptional(_pokeySound);
        }

        #endregion
    }
}