diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/QuickNES/LibQuickNES.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/QuickNES/LibQuickNES.cs
index 6eab122a15..79d83b72b1 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/QuickNES/LibQuickNES.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/QuickNES/LibQuickNES.cs
@@ -192,6 +192,22 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.QuickNES
 		/// <returns></returns>
 		[DllImport(dllname, CallingConvention = CallingConvention.Cdecl)]
 		public static extern bool qn_get_memory_area(IntPtr e, int which, ref IntPtr data, ref int size, ref bool writable, ref IntPtr name);
+		/// <summary>
+		/// peek the system bus
+		/// </summary>
+		/// <param name="e">Context</param>
+		/// <param name="addr">0000:ffff, but non-ram/rom addresses won't work</param>
+		/// <returns></returns>
+		[DllImport(dllname, CallingConvention = CallingConvention.Cdecl)]
+		public static extern byte qn_peek_prgbus(IntPtr e, int addr);
+		/// <summary>
+		/// poke the system bus
+		/// </summary>
+		/// <param name="e">Context</param>
+		/// <param name="addr">0000:ffff, but non-ram/rom addresses won't work</param>
+		/// <param name="val"></param>
+		[DllImport(dllname, CallingConvention = CallingConvention.Cdecl)]
+		public static extern void qn_poke_prgbus(IntPtr e, int addr, byte val);
 
 		/// <summary>
 		/// handle "string error" as returned by some quicknes functions
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/QuickNES/QuickNES.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/QuickNES/QuickNES.cs
index d7377adce5..95fc4f827f 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/QuickNES/QuickNES.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/QuickNES/QuickNES.cs
@@ -292,25 +292,45 @@ namespace BizHawk.Emulation.Cores.Consoles.Nintendo.QuickNES
 
 					mm.Add(new MemoryDomain
 					(
-					Marshal.PtrToStringAnsi(name),
-					size,
-					MemoryDomain.Endian.Unknown,
-					delegate(int addr)
-					{
-						if (addr < 0 || addr >= size)
-							throw new ArgumentOutOfRangeException();
-						return p[addr];
-					},
-					delegate(int addr, byte val)
-					{
-						if (!writable)
-							return;
-						if (addr < 0 || addr >= size)
-							throw new ArgumentOutOfRangeException();
-						p[addr] = val;
-					}));
+						Marshal.PtrToStringAnsi(name),
+						size,
+						MemoryDomain.Endian.Unknown,
+						delegate(int addr)
+						{
+							if (addr < 0 || addr >= size)
+								throw new ArgumentOutOfRangeException();
+							return p[addr];
+						},
+						delegate(int addr, byte val)
+						{
+							if (!writable)
+								return;
+							if (addr < 0 || addr >= size)
+								throw new ArgumentOutOfRangeException();
+							p[addr] = val;
+						}
+					));
 				}
 			}
+			// add system bus
+			mm.Add(new MemoryDomain
+			(
+				"System Bus",
+				0x10000,
+				MemoryDomain.Endian.Unknown,
+				delegate(int addr)
+				{
+					if (addr < 0 || addr >= 0x10000)
+						throw new ArgumentOutOfRangeException();
+					return LibQuickNES.qn_peek_prgbus(Context, addr);
+				},
+				delegate(int addr, byte val)
+				{
+					if (addr < 0 || addr >= 0x10000)
+						throw new ArgumentOutOfRangeException();
+					LibQuickNES.qn_poke_prgbus(Context, addr, val);
+				}
+			));
 			MemoryDomains = new MemoryDomainList(mm, 0);
 		}
 
diff --git a/output/dll/libquicknes.dll b/output/dll/libquicknes.dll
index 8b713d283a..b1c2e2ff67 100644
Binary files a/output/dll/libquicknes.dll and b/output/dll/libquicknes.dll differ
diff --git a/quicknes/bizinterface.cpp b/quicknes/bizinterface.cpp
index c35d70e8b0..a8a29374d8 100644
--- a/quicknes/bizinterface.cpp
+++ b/quicknes/bizinterface.cpp
@@ -228,3 +228,13 @@ EXPORT int qn_get_memory_area(Nes_Emu *e, int which, const void **data, int *siz
 		return 1;
 	}
 }
+
+EXPORT unsigned char qn_peek_prgbus(Nes_Emu *e, int addr)
+{
+	return e->peek_prg(addr & 0xffff);
+}
+
+EXPORT void qn_poke_prgbus(Nes_Emu *e, int addr, unsigned char val)
+{
+	e->poke_prg(addr & 0xffff, val);
+}
diff --git a/quicknes/nes_emu/Nes_Emu.h b/quicknes/nes_emu/Nes_Emu.h
index 81d47f154c..c3394e2154 100644
--- a/quicknes/nes_emu/Nes_Emu.h
+++ b/quicknes/nes_emu/Nes_Emu.h
@@ -197,7 +197,12 @@ public:
 	// Optional 8K memory
 	enum { high_mem_size = 0x2000 };
 	byte* high_mem()            { return emu.impl->sram; }
-	
+
+// Prg peek/poke for debuggin
+	byte peek_prg(nes_addr_t addr) const { return *static_cast<Nes_Cpu>(emu).get_code(addr); }
+	void poke_prg(nes_addr_t addr, byte value) { *static_cast<Nes_Cpu>(emu).get_code(addr) = value; }
+
+
 	// End of public interface
 public:
 	blargg_err_t set_sample_rate( long rate, class Nes_Buffer* );