diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/APU.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/APU.cs
index 69991b2f0f..34346c51cc 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/APU.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/APU.cs
@@ -1,4 +1,5 @@
 //TODO - so many integers in the square wave output keep us from exactly unbiasing the waveform. also other waves probably
+//TODO - DMC cpu suspending - http://forums.nesdev.com/viewtopic.php?p=62690#p62690
 
 using System;
 using System.IO;
@@ -592,6 +593,11 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 						Clock();
 					}
 
+					SyncSample();
+				}
+
+				void SyncSample()
+				{
 					if (out_silence)
 						sample = 0;
 					else
@@ -601,13 +607,6 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 					}
 				}
 
-				void SyncSample()
-				{
-					//sample = (out_deltacounter - 64) / 4;
-					//Console.WriteLine("dmc sample: {0}", sample);
-					//sample -= 64; //unbias
-				}
-
 				void Clock()
 				{
 					if (!out_silence)
@@ -692,6 +691,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 							break;
 						case 1:
 							out_deltacounter = val & 0x7F;
+							out_silence = false;
 							//apu.nes.LogLine("~~ out_deltacounter set to {0}", out_deltacounter);
 							SyncSample();
 							break;
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/BoardSystem.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/BoardSystem.cs
index d59a0735f9..991d6541b3 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/BoardSystem.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/BoardSystem.cs
@@ -188,11 +188,13 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			public virtual byte ReadWRAM(int addr) {
 				if (wram != null)
 					return wram[addr & wram_mask];
-				else return 0xFF;
+				else return NES.DB;
 			}
 
 			public virtual void WriteEXP(int addr, byte value) { }
-			public virtual byte ReadEXP(int addr) { return 0xFF; }
+			public virtual byte ReadEXP(int addr) { 
+				return NES.DB;
+			}
 
 			public virtual void WritePPU(int addr, byte value)
 			{
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Core.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Core.cs
index b403449bd1..4000311ec0 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Core.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Core.cs
@@ -22,7 +22,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 		CartInfo cart; //the current cart prototype. should be moved into the board, perhaps
 		INESBoard board; //the board hardware that is currently driving things
 		public bool SoundOn = true;
-		int sprdma_countdown; //used to 
+		int sprdma_countdown;
 		bool _irq_apu; //various irq signals that get merged to the cpu irq pin
 
 		//irq state management
@@ -119,7 +119,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 					{
 						//its weird that this is 514.. normally itd be 512 (and people would say its wrong) or 513 (and people would say its right)
 						//but 514 passes test 4-irq_and_dma
-						cpu_deadcounter = 514;
+						cpu_deadcounter += 514;
 					}
 				}
 
@@ -259,6 +259,9 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			}
 		}
 
+		//old data bus values from previous reads
+		public byte DB;
+
 		public byte ReadMemory(ushort addr)
 		{
 			byte ret;
@@ -301,6 +304,8 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				ret = sysbus_watch[addr].ApplyGameGenie(ret);
 			}
 
+			DB = ret;
+
 			return ret;
 		}
 
diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs
index ce0857388d..cef4a83e12 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/NES.cs
@@ -268,7 +268,7 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 			{
 				int ret = value & 1;
 				value >>= 1;
-				return (byte)ret;
+				return (byte)(ret | nes.DB);
 			}
 			public override void Update()
 			{
@@ -621,7 +621,9 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 
 		void SyncState(Serializer ser)
 		{
+			int version = 2;
 			ser.BeginSection("NES");
+			ser.Sync("version", ref version);
 			ser.Sync("Frame", ref _frame);
 			ser.Sync("Lag", ref _lagcount);
 			ser.Sync("IsLag", ref islag);
@@ -639,6 +641,9 @@ namespace BizHawk.Emulation.Consoles.Nintendo
 				throw new InvalidOperationException("the current NES mapper didnt call base.SyncState");
 			ppu.SyncState(ser);
 			apu.SyncState(ser);
+			if (version >= 2)
+				ser.Sync("DB", ref DB);
+
 			ser.EndSection();
 		}