diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index 10ba63cfb3..ff25860ed9 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -312,7 +312,6 @@
     <Compile Include="Computers\SinclairSpectrum\ZXSpectrum.IInputPollable.cs" />
     <Compile Include="Computers\SinclairSpectrum\ZXSpectrum.IMemoryDomains.cs" />
     <Compile Include="Computers\SinclairSpectrum\ZXSpectrum.ISettable.cs" />
-    <Compile Include="Computers\SinclairSpectrum\ZXSpectrum.ISoundProvider.cs" />
     <Compile Include="Computers\SinclairSpectrum\ZXSpectrum.IStatable.cs" />
     <Compile Include="Computers\SinclairSpectrum\ZXSpectrum.Util.cs" />
     <Compile Include="Consoles\Atari\2600\Atari2600.cs" />
@@ -1393,7 +1392,6 @@
     <Compile Include="Computers\SinclairSpectrum\Machine\ZXSpectrum48K\ZX48.Keyboard.cs" />
     <Compile Include="Computers\SinclairSpectrum\Machine\ZXSpectrum48K\ZX48.Port.cs" />
     <None Include="Computers\SinclairSpectrum\readme.md" />
-    <Compile Include="Computers\SinclairSpectrum\ZXSpectrum.IVideoProvider.cs" />
     <None Include="Consoles\Atari\docs\stella.pdf" />
     <None Include="Consoles\Coleco\docs\colecovision tech1.pdf" />
     <None Include="Consoles\Coleco\docs\colecovision tech2.pdf" />
diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/Interfaces/ISupportsTapeBlockPlayback.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/Interfaces/ISupportsTapeBlockPlayback.cs
index 969944fa92..8d1c47645b 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/Interfaces/ISupportsTapeBlockPlayback.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/Interfaces/ISupportsTapeBlockPlayback.cs
@@ -1,4 +1,5 @@
-using System;
+using BizHawk.Common;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
@@ -35,5 +36,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         /// The EAR bit value to play back
         /// </returns>
         bool GetEarBit(long currentCycle);
+
+
+        void SyncState(Serializer ser);
     }
 }
diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/Tape.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/Tape.cs
index 203fef91b2..fd29eb3855 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/Tape.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/Tape.cs
@@ -526,9 +526,6 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
             ser.SyncEnum<TapeOperationMode>("_currentMode", ref _currentMode);
             ser.SyncEnum<SavePhase>("_savePhase", ref _savePhase);
             ser.SyncEnum<MicPulseType>("_prevDataPulse", ref _prevDataPulse);
-            /*
-        private TapeFilePlayer _tapePlayer;
-        */
 
             ser.EndSection();
         }
diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/TapeBlockSetPlayer.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/TapeBlockSetPlayer.cs
index c08b488acf..6d5b149f9e 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/TapeBlockSetPlayer.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/TapeBlockSetPlayer.cs
@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using BizHawk.Common;
+using System.Collections.Generic;
 
 namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 {
@@ -15,27 +16,56 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         /// <summary>
         /// Signs that the player completed playing back the file
         /// </summary>
-        public bool Eof { get; private set; }
+        private bool eof;
+        public bool Eof
+        {
+            get { return eof; }
+            set { eof = value; }
+        }
+
 
         /// <summary>
         /// Gets the currently playing block's index
         /// </summary>
-        public int CurrentBlockIndex { get; private set; }
+        private int currentBlockIndex;
+        public int CurrentBlockIndex
+        {
+            get { return currentBlockIndex; }
+            set { currentBlockIndex = value; }
+        }
 
         /// <summary>
         /// The current playable block
         /// </summary>
-        public ISupportsTapeBlockPlayback CurrentBlock => DataBlocks[CurrentBlockIndex];
+        private ISupportsTapeBlockPlayback currentBlock;
+        public ISupportsTapeBlockPlayback CurrentBlock
+        {
+            get { return DataBlocks[CurrentBlockIndex]; }
+            //set { currentBlock = value; }
+        }
+
 
         /// <summary>
         /// The current playing phase
         /// </summary>
-        public PlayPhase PlayPhase { get; private set; }
+        private PlayPhase playPhase;
+        public PlayPhase PlayPhase
+        {
+            get { return playPhase; }
+            set { playPhase = value; }
+        }
+
 
         /// <summary>
         /// The cycle count of the CPU when playing starts
         /// </summary>
-        public long StartCycle { get; private set; }
+        private long startCycle;
+        public long StartCycle
+        {
+            get { return startCycle; }
+            set { startCycle = value; }
+        }
+
 
         public TapeBlockSetPlayer(List<ISupportsTapeBlockPlayback> dataBlocks)
         {
@@ -98,5 +128,16 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
             CurrentBlockIndex++;
             CurrentBlock.InitPlay(currentCycle);
         }
+
+        public void SyncState(Serializer ser)
+        {
+            ser.BeginSection("TapeBlockSetPlayer");
+            ser.Sync("eof", ref eof);
+            ser.Sync("currentBlockIndex", ref currentBlockIndex);
+            ser.SyncEnum<PlayPhase>("playPhase", ref playPhase);
+            ser.Sync("startCycle", ref startCycle);
+            currentBlock.SyncState(ser);
+            ser.EndSection();
+        }
     }
 }
diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/TapeDataBlockPlayer.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/TapeDataBlockPlayer.cs
index 547d7698b9..0c7dae4f14 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/TapeDataBlockPlayer.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/TapeDataBlockPlayer.cs
@@ -1,4 +1,6 @@
 
+using BizHawk.Common;
+
 namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 {
     /// <summary>
@@ -9,20 +11,28 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         /// <summary>
         /// Pause after this block (default: 1000ms)
         /// </summary>
-        public ushort PauseAfter { get; }
+        private ushort pauseAfter;
+        public ushort PauseAfter
+        {
+            get { return pauseAfter; }
+        }
 
         /// <summary>
         /// Block Data
         /// </summary>
-        public byte[] Data { get; }
+        private byte[] data;
+        public byte[] Data
+        {
+            get { return data; }
+        }
 
         /// <summary>
         /// Initializes a new instance
         /// </summary>
-        public TapeDataBlockPlayer(byte[] data, ushort pauseAfter)
+        public TapeDataBlockPlayer(byte[] _data, ushort _pauseAfter)
         {
-            PauseAfter = pauseAfter;
-            Data = data;
+            pauseAfter = _pauseAfter;
+            data = _data;
         }
 
         /// <summary>
@@ -82,27 +92,52 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         /// <summary>
         /// The index of the currently playing byte
         /// </summary>
-        public int ByteIndex { get; private set; }
+        private int byteIndex;
+        public int ByteIndex
+        {
+            get { return byteIndex; }
+            set { byteIndex = value; }
+        }
 
         /// <summary>
         /// The mask of the currently playing bit in the current byte
         /// </summary>
-        public byte BitMask { get; private set; }
+        private byte bitMask;
+        public byte BitMask
+        {
+            get { return bitMask; }
+            set { bitMask = value; }
+        }
 
         /// <summary>
         /// The current playing phase
         /// </summary>
-        public PlayPhase PlayPhase { get; private set; }
+        private PlayPhase playPhase;
+        public PlayPhase PlayPhase
+        {
+            get { return playPhase; }
+            set { playPhase = value; }
+        }
 
         /// <summary>
         /// The cycle count of the CPU when playing starts
         /// </summary>
-        public long StartCycle { get; private set; }
+        private long startCycle;
+        public long StartCycle
+        {
+            get { return startCycle; }
+            set { startCycle = value; }
+        }
 
         /// <summary>
         /// Last cycle queried
         /// </summary>
-        public long LastCycle { get; private set; }
+        private long lastCycle;
+        public long LastCycle
+        {
+            get { return lastCycle; }
+            set { lastCycle = value; }
+        }
 
         /// <summary>
         /// Initializes the player
@@ -214,5 +249,31 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
             }
             return true;
         }
+
+
+        public void SyncState(Serializer ser)
+        {
+            ser.BeginSection("TapeDataBlockPlayer");
+
+            ser.Sync("pauseAfter", ref pauseAfter);
+            ser.Sync("data", ref data, false);
+
+            ser.Sync("_pilotEnds", ref _pilotEnds);
+            ser.Sync("_sync1Ends", ref _sync1Ends);
+            ser.Sync("_sync2Ends", ref _sync2Ends);
+            ser.Sync("_bitStarts", ref _bitStarts);
+            ser.Sync("_bitPulseLength", ref _bitPulseLength);
+            ser.Sync("_currentBit", ref _currentBit);
+            ser.Sync("_termSyncEnds", ref _termSyncEnds);
+            ser.Sync("_pauseEnds", ref _pauseEnds);
+
+            ser.Sync("byteIndex", ref byteIndex);
+            ser.Sync("bitMask", ref bitMask);
+            ser.SyncEnum<PlayPhase>("playPhase", ref playPhase);
+            ser.Sync("startCycle", ref startCycle);
+            ser.Sync("lastCycle", ref lastCycle);
+            
+            ser.EndSection();
+        }
     }
 }
diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/TapeFilePlayer.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/TapeFilePlayer.cs
index 25c75df0f8..92c32dbc95 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/TapeFilePlayer.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Hardware/TapeFilePlayer.cs
@@ -1,4 +1,5 @@
-using System;
+using BizHawk.Common;
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -13,6 +14,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
     {
         private readonly BinaryReader _reader;
         private TapeBlockSetPlayer _player;
+        private int _numberOfDataBlocks;
 
         /// <summary>
         /// Data blocks to play back
@@ -113,5 +115,14 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         /// </summary>
         /// <param name="currentTact">Tacts time to start the next block</param>
         public void NextBlock(long currentCycle) => _player.NextBlock(currentCycle);
+
+        public void SyncState(Serializer ser)
+        {
+            ser.BeginSection("TapeFilePlayer");
+            ReadContent();
+            ser.Sync("_numberOfDataBlocks", ref _numberOfDataBlocks);
+            _player.SyncState(ser);        
+            ser.EndSection();
+        }
     }
 }
diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/SpectrumBase.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/SpectrumBase.cs
index 516b7d4b4d..a67333aa03 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/SpectrumBase.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Machine/SpectrumBase.cs
@@ -142,7 +142,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
             // paint the buffer if needed
             if (ULADevice.needsPaint)
                 ULADevice.UpdateScreenBuffer(ULADevice.FrameLength);
-
+            
             BuzzerDevice.EndFrame();            
 
             TapeDevice.CPUFrameCompleted();
diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TAP/TapDataBlock.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TAP/TapDataBlock.cs
index 3c4858b533..0682b32752 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TAP/TapDataBlock.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TAP/TapDataBlock.cs
@@ -1,4 +1,5 @@
 
+using BizHawk.Common;
 using System.IO;
 
 namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
@@ -16,7 +17,12 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         /// <summary>
         /// Block Data
         /// </summary>
-        public byte[] Data { get; private set; }
+        private byte[] data;
+        public byte[] Data
+        {
+            get { return data; }
+            set { data = value; }
+        }
 
         /// <summary>
         /// Pause after this block (given in milliseconds)
@@ -86,5 +92,14 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         /// The EAR bit value to play back
         /// </returns>
         public bool GetEarBit(long currentTact) => _player.GetEarBit(currentTact);
+
+        public void SyncState(Serializer ser)
+        {
+            ser.BeginSection("TapDataBlock");
+
+            ser.Sync("data", ref data, false);
+
+            ser.EndSection();
+        }
     }
 }
diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TAP/TapPlayer.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TAP/TapPlayer.cs
index faa7d23c02..0c24566e37 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TAP/TapPlayer.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TAP/TapPlayer.cs
@@ -1,4 +1,5 @@
 
+using BizHawk.Common;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -81,5 +82,15 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         /// </summary>
         /// <param name="currentCycle">Tacts time to start the next block</param>
         public void NextBlock(long currentCycle) => _player.NextBlock(currentCycle);
+
+
+        public void SyncState(Serializer ser)
+        {
+            ser.BeginSection("TapePlayer");
+
+            _player.SyncState(ser);
+
+            ser.EndSection();
+        }
     }
 }
diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TZX/DataBlocks.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TZX/DataBlocks.cs
index 18ce828a09..cfd694d544 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TZX/DataBlocks.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TZX/DataBlocks.cs
@@ -1,4 +1,5 @@
 
+using BizHawk.Common;
 using System.IO;
 
 namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
@@ -1144,12 +1145,23 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         /// <summary>
         /// Lenght of block data
         /// </summary>
-        public ushort DataLength { get; set; }
+        private ushort dataLength;
+        public ushort DataLength
+        {
+            get { return dataLength; }
+            set { dataLength = value; }
+        }
 
         /// <summary>
         /// Block Data
         /// </summary>
-        public byte[] Data { get; set; }
+        private byte[] data;
+        public byte[] Data
+        {
+            get { return data; }
+            set { data = value; }
+        }
+
 
         /// <summary>
         /// The ID of the block
@@ -1222,6 +1234,16 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         /// The EAR bit value to play back
         /// </returns>
         public bool GetEarBit(long currentCycle) => _player.GetEarBit(currentCycle);
+
+        public void SyncState(Serializer ser)
+        {
+            ser.BeginSection("TzxStandardSpeedDataBlock");
+
+            ser.Sync("dataLength", ref dataLength);
+            ser.Sync("data", ref data, false);
+
+            ser.EndSection();
+        }
     }
 
     /// <summary>
diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TZX/TzxPlayer.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TZX/TzxPlayer.cs
index 55797b80df..a9ac846467 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TZX/TzxPlayer.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/Media/Tape/TZX/TzxPlayer.cs
@@ -1,4 +1,5 @@
-using System.IO;
+using BizHawk.Common;
+using System.IO;
 using System.Linq;
 
 namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
@@ -79,5 +80,15 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         /// </summary>
         /// <param name="currentTact">Tacts time to start the next block</param>
         public void NextBlock(long currentTact) => _player.NextBlock(currentTact);
+
+
+        public void SyncState(Serializer ser)
+        {
+            ser.BeginSection("TzxPlayer");
+
+            _player.SyncState(ser);
+
+            ser.EndSection();
+        }
     }
 }
diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.IEmulator.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.IEmulator.cs
index b7a1a07d82..8b10763146 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.IEmulator.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.IEmulator.cs
@@ -29,7 +29,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
 
         public string SystemId => "ZXSpectrum";
 
-        public bool DeterministicEmulation => false;
+        public bool DeterministicEmulation => true;
 
         public void ResetCounters()
         {
diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.ISoundProvider.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.ISoundProvider.cs
deleted file mode 100644
index 402b7f292d..0000000000
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.ISoundProvider.cs
+++ /dev/null
@@ -1,14 +0,0 @@
-using BizHawk.Emulation.Cores.Components;
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
-{
-    public partial class ZXSpectrum
-    {
-        private SoundProviderMixer SoundMixer;
-    }
-}
diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.IVideoProvider.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.IVideoProvider.cs
deleted file mode 100644
index 073236a69d..0000000000
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.IVideoProvider.cs
+++ /dev/null
@@ -1,13 +0,0 @@
-using System;
-
-namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
-{
-	/// <summary>
-    /// Main IVideoProvider implementation is inside the machine classes
-    /// This is just some helper functions
-    /// </summary>
-    public partial class ZXSpectrum
-    {
-		
-    }
-}
diff --git a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.cs b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.cs
index ac8fd29229..6694a7e97d 100644
--- a/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.cs
+++ b/BizHawk.Emulation.Cores/Computers/SinclairSpectrum/ZXSpectrum.cs
@@ -60,9 +60,7 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
                     break;
                 default:
                     throw new InvalidOperationException("Machine not yet emulated");
-            }       
-
-            
+            }  
             
             _cpu.MemoryCallbacks = MemoryCallbacks;
 
@@ -84,14 +82,8 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
             if (_machine.AYDevice != null)
                 SoundMixer.AddSource(_machine.AYDevice);
 
-            //SoundMixer.DisableSource(_machine.BuzzerDevice);
-
-            dcf = new DCFilter(SoundMixer, 1024);
-
-            
-
+            dcf = new DCFilter(SoundMixer, 256);
             ser.Register<ISoundProvider>(dcf);
-            //ser.Register<ISoundProvider>(_machine.AYDevice);
 
             
 
@@ -108,11 +100,12 @@ namespace BizHawk.Emulation.Cores.Computers.SinclairSpectrum
         public IController _controller;
         private SpectrumBase _machine;
 
+        private SoundProviderMixer SoundMixer;
+
         private DCFilter dcf;
 
         private byte[] _file;
 
-
         public bool DiagRom = false;
 
         private byte[] GetFirmware(int length, params string[] names)