diff --git a/src/debugger/CartDebug.cxx b/src/debugger/CartDebug.cxx
index 515d79a98..79f8abe7a 100644
--- a/src/debugger/CartDebug.cxx
+++ b/src/debugger/CartDebug.cxx
@@ -171,7 +171,7 @@ int CartDebug::readFromWritePort()
   // port address space AND the last access was actually a read (the latter
   // differentiates between reads that are normally part of a write cycle vs.
   // ones that are illegal)
-  if(mySystem.m6502().lastRealReadAddress() &&
+  if(mySystem.m6502().lastReadAddress() &&
       (mySystem.getPageAccessType(addr) & System::PA_WRITE) == System::PA_WRITE)
     return addr;
   else
diff --git a/src/debugger/CartDebug.hxx b/src/debugger/CartDebug.hxx
index c9c0531ff..a513c678a 100644
--- a/src/debugger/CartDebug.hxx
+++ b/src/debugger/CartDebug.hxx
@@ -128,10 +128,10 @@ class CartDebug : public DebuggerSystem
     // write port area.
     int readFromWritePort();
 
-    // Return the address of the last CPU read
-    int lastReadAddress() { return mySystem.m6502().lastReadAddress(); }
-    // Return the address of the last CPU write
-    int lastWriteAddress() { return mySystem.m6502().lastWriteAddress(); }
+    // Return the base (= non-mirrored) address of the last CPU read
+    int lastReadBaseAddress() { return mySystem.m6502().lastReadBaseAddress(); }
+    // Return the base (= non-mirrored) address of the last CPU write
+    int lastWriteBaseAddress() { return mySystem.m6502().lastWriteBaseAddress(); }
 
     // The following two methods are meant to be used together
     // First, a call is made to disassemble(), which updates the disassembly
diff --git a/src/debugger/Debugger.cxx b/src/debugger/Debugger.cxx
index aee0a7d6f..50dc315ae 100644
--- a/src/debugger/Debugger.cxx
+++ b/src/debugger/Debugger.cxx
@@ -440,39 +440,48 @@ bool Debugger::writeTrap(uInt16 t)
 {
   return writeTraps().isInitialized() && writeTraps().isSet(t);
 }
-
-/*// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Debugger::toggleReadTrapIf(uInt16 t)
-{
-  readTrapIfs().initialize();
-  readTrapIfs().toggle(t);
-}
-
+                                                                              
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Debugger::toggleWriteTrapIf(uInt16 t)
+uInt32 Debugger::getBaseAddress(uInt32 addr, bool read)
 {
-  writeTrapIfs().initialize();
-  writeTrapIfs().toggle(t);
-}
+  if((addr & 0x1080) == 0x0000) // (addr & 0b 0001 0000 1000 0000) == 0b 0000 0000 0000 0000
+    if(read)
+      // ADDR_TIA read (%xxx0 xxxx 0xxx ????)
+      return addr & 0x000f; // 0b 0000 0000 0000 1111
+    else
+      // ADDR_TIA write (%xxx0 xxxx 0x?? ????)
+      return addr & 0x003f; // 0b 0000 0000 0011 1111
 
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-void Debugger::toggleTrapIf(uInt16 t)
-{
-  toggleReadTrapIf(t);
-  toggleWriteTrapIf(t);
-}
+                            // ADDR_ZPRAM (%xxx0 xx0x 1??? ????)
+  if((addr & 0x1280) == 0x0080) // (addr & 0b 0001 0010 1000 0000) == 0b 0000 0000 1000 0000
+    return addr & 0x00ff; // 0b 0000 0000 1111 1111
 
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-bool Debugger::readTrapIf(uInt16 t)
-{
-  return readTrapIfs().isInitialized() && readTrapIfs().isSet(t);
-}
+                          // ADDR_ROM
+  if(addr & 0x1000)
+    return addr & 0x1fff; // 0b 0001 1111 1111 1111
 
-// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
-bool Debugger::writeTrapIf(uInt16 t)
-{
-  return writeTrapIfs().isInitialized() && writeTrapIfs().isSet(t);
-}*/
+                          // ADDR_IO read/write I/O registers (%xxx0 xx1x 1xxx x0??)
+  if((addr & 0x1284) == 0x0280) // (addr & 0b 0001 0010 1000 0100) == 0b 0000 0010 1000 0000
+    return addr & 0x0283; // 0b 0000 0010 1000 0011
+
+                          // ADDR_IO write timers (%xxx0 xx1x 1xx1 ?1??)
+  if(!read && (addr & 0x1294) == 0x0294) // (addr & 0b 0001 0010 1001 0100) == 0b 0000 0010 1001 0100
+    return addr & 0x029f; // 0b 0000 0010 1001 1111
+
+                          // ADDR_IO read timers (%xxx0 xx1x 1xxx ?1x0)
+  if(read && (addr & 0x1285) == 0x0284) // (addr & 0b 0001 0010 1000 0101) == 0b 0000 0010 1000 0100
+    return addr & 0x028c; // 0b 0000 0010 1000 1100
+
+                          // ADDR_IO read timer/PA7 interrupt (%xxx0 xx1x 1xxx x1x1)
+  if(read && (addr & 0x1285) == 0x0285) // (addr & 0b 0001 0010 1000 0101) == 0b 0000 0010 1000 0101
+    return addr & 0x0285; // 0b 0000 0010 1000 0101
+
+                          // ADDR_IO write PA7 edge control (%xxx0 xx1x 1xx0 x1??)
+  if(!read && (addr & 0x1294) == 0x0284) // (addr & 0b 0001 0010 1001 0100) == 0b 0000 0010 1000 0100
+    return addr & 0x0287; // 0b 0000 0010 1000 0111    
+
+  return 0;
+}
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 void Debugger::nextScanline(int lines)
diff --git a/src/debugger/Debugger.hxx b/src/debugger/Debugger.hxx
index e142888b6..118a33558 100644
--- a/src/debugger/Debugger.hxx
+++ b/src/debugger/Debugger.hxx
@@ -216,6 +216,7 @@ class Debugger : public DialogContainer
       { mySystem.setAccessFlags(addr, flags); }
 
     void setBreakPoint(uInt16 bp, bool set);
+    uInt32 getBaseAddress(uInt32 addr, bool read);
 
     bool patchROM(uInt16 addr, uInt8 value);
 
diff --git a/src/debugger/DebuggerParser.cxx b/src/debugger/DebuggerParser.cxx
index 85d01fdc2..3f5f07082 100644
--- a/src/debugger/DebuggerParser.cxx
+++ b/src/debugger/DebuggerParser.cxx
@@ -1144,6 +1144,13 @@ void DebuggerParser::executeListfunctions()
 void DebuggerParser::executeListtraps()
 {
   StringList names = debugger.cpuDebug().m6502().getCondTrapNames();
+
+  if(myTraps.size() != names.size())
+  {
+    commandResult << "Internal error! Different trap sizes.";
+    return;
+  }
+           
   if (names.size() > 0)
   {
     for(uInt32 i = 0; i < names.size(); i++)
@@ -1579,6 +1586,11 @@ void DebuggerParser::executeTraps(bool read, bool write, string command, bool ha
   int ofs = hasCond ? 1 : 0;
   uInt32 begin = args[ofs];
   uInt32 end = argCount == ofs + 2 ? args[ofs + 1] : begin;
+  // mirrors
+  uInt32 beginRead  = debugger.getBaseAddress(begin, true);
+  uInt32 endRead    = debugger.getBaseAddress(end,   true);
+  uInt32 beginWrite = debugger.getBaseAddress(begin, false);
+  uInt32 endWrite   = debugger.getBaseAddress(end,   false);
 
   if(begin > 0xFFFF || end > 0xFFFF || begin > end)
   {
@@ -1590,27 +1602,23 @@ void DebuggerParser::executeTraps(bool read, bool write, string command, bool ha
   stringstream parserBuf, displayBuf;
   if(hasCond)
     parserBuf << "(" << argStrings[0] << ")&&(";
-
-  // TODO: mirrors
-  //begin = getBaseMirror(begin);
-  //end = getBaseMirror(eng);
-
+                        
   // add address range condition(s) to provided condition
   if(read)
   { 
-    if(begin != end)
-      parserBuf << "_lastread>=" << Base::toString(begin) << "&&_lastread<=" << Base::toString(end);
+    if(beginRead != endRead)
+      parserBuf << "_lastread>=" << Base::toString(beginRead) << "&&_lastread<=" << Base::toString(endRead);
     else
-      parserBuf << "_lastread==" << Base::toString(begin);
+      parserBuf << "_lastread==" << Base::toString(beginRead);
   }
   if(read && write)
     parserBuf << "||";
   if(write)
   {
-    if(begin != end)
-      parserBuf << "_lastwrite>=" << Base::toString(begin) << "&&_lastwrite<=" << Base::toString(end);
+    if(beginWrite != endWrite)
+      parserBuf << "_lastwrite>=" << Base::toString(beginWrite) << "&&_lastwrite<=" << Base::toString(endWrite);
     else
-      parserBuf << "_lastwrite==" << Base::toString(begin);
+      parserBuf << "_lastwrite==" << Base::toString(beginWrite);
   }
   // parenthesize provided condition (end)
   if(hasCond)
@@ -1660,47 +1668,6 @@ void DebuggerParser::executeTraps(bool read, bool write, string command, bool ha
   } 
 }
 
-uInt32 getBaseAddress(uInt32 addr, bool read)
-{  
-  // ADDR_TIA write (%xxx0 xxxx 0x?? ????)
-  if(!read && (addr & 0x1080) == 0x0000) // (addr & 0b 0001 0000 1000 0000) == 0b 0000 0000 0000 0000
-    return addr & 0x003f; // 0b 0000 0000 0011 1111
-
-  // ADDR_TIA read (%xxx0 xxxx 0xxx ????)
-  if(read && (addr & 0x1080) == 0x0000) // (addr & 0b 0001 0000 1000 0000) == 0b 0000 0000 0000 0000
-    return addr & 0x000f; // 0b 0000 0000 0000 1111
-
-  // ADDR_ZPRAM (%xxx0 xx0x 1??? ????)
-  if((addr & 0x1280) == 0x0080) // (addr & 0b 0001 0010 1000 0000) == 0b 0000 0000 1000 0000
-    return addr & 0x00ff; // 0b 0000 0000 1111 1111
-
-  // ADDR_ROM
-  if(addr & 0x1000)
-    return addr & 0x1fff; // 0b 0001 1111 1111 1111
-
-  // ADDR_IO read/write I/O registers (%xxx0 xx1x 1xxx x0??)
-  if((addr & 0x1284) == 0x0280) // (addr & 0b 0001 0010 1000 0100) == 0b 0000 0010 1000 0000
-    return addr & 0x0283; // 0b 0000 0010 1000 0011
-
-  // ADDR_IO write timers (%xxx0 xx1x 1xx1 ?1??)
-  if(!read && (addr & 0x1294) == 0x0294) // (addr & 0b 0001 0010 1001 0100) == 0b 0000 0010 1001 0100
-    return addr & 0x029f; // 0b 0000 0010 1001 1111
-
-  // ADDR_IO read timers (%xxx0 xx1x 1xxx ?1x0)
-  if(read && (addr & 0x1285) == 0x0284) // (addr & 0b 0001 0010 1000 0101) == 0b 0000 0010 1000 0100
-    return addr & 0x028c; // 0b 0000 0010 1000 1100
-    
-  // ADDR_IO read timer/PA7 interrupt (%xxx0 xx1x 1xxx x1x1)
-  if(read && (addr & 0x1285) == 0x0285) // (addr & 0b 0001 0010 1000 0101) == 0b 0000 0010 1000 0101
-    return addr & 0x0285; // 0b 0000 0010 1000 0101
-
-  // ADDR_IO write PA7 edge control (%xxx0 xx1x 1xx0 x1??)
-  if(!read && (addr & 0x1294) == 0x0284) // (addr & 0b 0001 0010 1001 0100) == 0b 0000 0010 1000 0100
-    return addr & 0x0287; // 0b 0000 0010 1000 0111    
-
-  return 0;
-}
-
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 // wrapper function for trap(if)/trapread(if)/trapwrite(if) commands
 void DebuggerParser::executeTrapRW(uInt32 addr, bool read, bool write, bool add)
diff --git a/src/emucore/M6502.cxx b/src/emucore/M6502.cxx
index 9b2ec4096..04a93e40d 100644
--- a/src/emucore/M6502.cxx
+++ b/src/emucore/M6502.cxx
@@ -126,7 +126,7 @@ inline uInt8 M6502::peek(uInt16 address, uInt8 flags)
 #ifdef DEBUGGER_SUPPORT
   if(myReadTraps.isInitialized() && myReadTraps.isSet(address))
   {
-    //TODO: myLastPeekBaseAddress = baseAddress(myLastPeekAddress); // mirror handling
+    myLastPeekBaseAddress = myDebugger->getBaseAddress(myLastPeekAddress, true); // mirror handling
     int cond = evalCondTraps();
     if(cond > -1)
     {
@@ -159,7 +159,7 @@ inline void M6502::poke(uInt16 address, uInt8 value, uInt8 flags)
 #ifdef DEBUGGER_SUPPORT
   if(myWriteTraps.isInitialized() && myWriteTraps.isSet(address))
   {
-    //TODO: myLastPokeBaseAddress = baseAddress(myLastPokeAddress); // mirror handling
+    myLastPokeBaseAddress = myDebugger->getBaseAddress(myLastPokeAddress, false); // mirror handling
     int cond = evalCondTraps();
     if(cond > -1)
     {
diff --git a/src/emucore/M6502.hxx b/src/emucore/M6502.hxx
index d13935761..2c96b1dea 100644
--- a/src/emucore/M6502.hxx
+++ b/src/emucore/M6502.hxx
@@ -145,7 +145,7 @@ class M6502 : public Serializable
 
       @return The address of the last read
     */
-    uInt16 lastRealReadAddress() const {
+    uInt16 lastReadAddress() const {
       return myLastPokeAddress ?
         (myLastPokeAddress != myLastPeekAddress ? myLastPeekAddress : 0) :
         myLastPeekAddress;
@@ -156,14 +156,14 @@ class M6502 : public Serializable
 
       @return The address of the last read
     */
-    uInt16 lastReadAddress() const { return myLastPeekAddress; }
+    uInt16 lastReadBaseAddress() const { return myLastPeekBaseAddress; }
 
     /**
       Return the last address that was part of a write/poke.  
 
       @return The address of the last write
     */
-    uInt16 lastWriteAddress() const { return myLastPokeAddress; }
+    uInt16 lastWriteBaseAddress() const { return myLastPokeBaseAddress; }
 
     /**
       Return the source of the address that was used for a write/poke.
@@ -355,6 +355,9 @@ class M6502 : public Serializable
     /// Indicates the last address which was accessed specifically
     /// by a peek or poke command
     uInt16 myLastPeekAddress, myLastPokeAddress;
+    /// Indicates the last base (= non-mirrored) address which was
+    /// accessed specifically by a peek or poke command
+    uInt16 myLastPeekBaseAddress, myLastPokeBaseAddress;
 
     /// Indicates the last address used to access data by a peek command
     /// for the CPU registers (S/A/X/Y)
diff --git a/src/yacc/YaccParser.cxx b/src/yacc/YaccParser.cxx
index 862970584..8f88ba239 100644
--- a/src/yacc/YaccParser.cxx
+++ b/src/yacc/YaccParser.cxx
@@ -207,9 +207,9 @@ CartMethod getCartSpecial(char* ch)
   else if(BSPF::equalsIgnoreCase(ch, "_rwport"))
     return &CartDebug::readFromWritePort;
   else if(BSPF::equalsIgnoreCase(ch, "_lastread"))
-    return &CartDebug::lastReadAddress;
+    return &CartDebug::lastReadBaseAddress;
   else if(BSPF::equalsIgnoreCase(ch, "_lastwrite"))
-    return &CartDebug::lastWriteAddress;
+    return &CartDebug::lastWriteBaseAddress;
   else
     return 0;
 }