diff --git a/source/Debugger/Debug.cpp b/source/Debugger/Debug.cpp
index 8e469a8a..4c12c51c 100644
--- a/source/Debugger/Debug.cpp
+++ b/source/Debugger/Debug.cpp
@@ -62,7 +62,6 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 	Bookmark_t g_aBookmarks[ MAX_BOOKMARKS ];
 
 // Breakpoints ________________________________________________________________
-
 	// Any Speed Breakpoints
 	int  g_nDebugBreakOnInvalid  = 0; // Bit Flags of Invalid Opcode to break on: // iOpcodeType = AM_IMPLIED (BRK), AM_1, AM_2, AM_3
 	int  g_iDebugBreakOnOpcode   = 0;
@@ -72,7 +71,7 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 	int  g_nBreakpoints          = 0;
 	Breakpoint_t g_aBreakpoints[ MAX_BREAKPOINTS ];
 
-	// NOTE: Breakpoint_Source_t and g_aBreakpointSource must match!
+	// NOTE: BreakpointSource_t and g_aBreakpointSource must match!
 	const char *g_aBreakpointSource[ NUM_BREAKPOINT_SOURCES ] =
 	{	// Used to be one char, since ArgsCook also uses // TODO/FIXME: Parser use Param[] ?
 		// Used for both Input & Output!
@@ -95,8 +94,9 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 		"N", // 1--- ---- Sign
 		// Misc
 		"OP", // Opcode/Instruction/Mnemonic
-		// Memory
-		"M" // Main
+		"M", // Mem RW
+		"M", // Mem READ_ONLY
+		"M", // Mem WRITE_ONLY
 		// TODO: M0 ram bank 0, M1 aux ram ?
 	};
 
@@ -1087,11 +1087,11 @@ bool _CheckBreakpointValue( Breakpoint_t *pBP, int nVal )
 				bStatus = true;
 			break;
 		case BP_OP_EQUAL        : // Range is like C++ STL: [,)  (inclusive,not-inclusive)
-			 if ((nVal >= pBP->nAddress) && (nVal < (pBP->nAddress + pBP->nLength)))
+			 if ((nVal >= pBP->nAddress) && ((UINT)nVal < (pBP->nAddress + pBP->nLength)))
 			 	bStatus = true;
 			break;
 		case BP_OP_NOT_EQUAL    : // Rnage is: (,] (not-inclusive, inclusive)
-			 if ((nVal < pBP->nAddress) || (nVal >= (pBP->nAddress + pBP->nLength)))
+			 if ((nVal < pBP->nAddress) || ((UINT)nVal >= (pBP->nAddress + pBP->nLength)))
 			 	bStatus = true;
 			break;
 		case BP_OP_GREATER_THAN :
@@ -1141,12 +1141,31 @@ int CheckBreakpointsIO ()
 					Breakpoint_t *pBP = &g_aBreakpoints[iBreakpoint];
 					if (_BreakpointValid( pBP ))
 					{
-						if (pBP->eSource == BP_SRC_MEM_1)
+						if (pBP->eSource == BP_SRC_MEM_RW || pBP->eSource == BP_SRC_MEM_READ_ONLY || pBP->eSource == BP_SRC_MEM_WRITE_ONLY)
 						{
 							if (_CheckBreakpointValue( pBP, nAddress ))
 							{
 								g_uBreakMemoryAddress = (WORD) nAddress;
-								return BP_HIT_MEM;
+								BYTE opcode = mem[regs.pc];
+
+								if (pBP->eSource == BP_SRC_MEM_RW)
+								{
+									return BP_HIT_MEM;
+								}
+								else if (pBP->eSource == BP_SRC_MEM_READ_ONLY)
+								{
+									if (g_aOpcodes[opcode].nMemoryAccess & (MEM_RI|MEM_R))
+										return BP_HIT_MEMR;
+								}
+								else if (pBP->eSource == BP_SRC_MEM_WRITE_ONLY)
+								{
+									if (g_aOpcodes[opcode].nMemoryAccess & (MEM_WI|MEM_W))
+										return BP_HIT_MEMW;
+								}
+								else
+								{
+									_ASSERT(0);
+								}
 							}
 						}
 					}
@@ -1335,6 +1354,9 @@ bool _CmdBreakpointAddReg( Breakpoint_t *pBP, BreakpointSource_t iSrc, Breakpoin
 
 	if (pBP)
 	{
+		_ASSERT(nLen <= _6502_MEM_LEN);
+		if (nLen > _6502_MEM_LEN) nLen = _6502_MEM_LEN;
+
 		pBP->eSource   = iSrc;
 		pBP->eOperator = iCmp;
 		pBP->nAddress  = nAddress;
@@ -1470,12 +1492,26 @@ Update_t CmdBreakpointAddIO   (int nArgs)
 //	return UPDATE_BREAKPOINTS | UPDATE_CONSOLE_DISPLAY;
 }
 
-
 //===========================================================================
-Update_t CmdBreakpointAddMem  (int nArgs)
+Update_t CmdBreakpointAddMemA(int nArgs)
 {
-	BreakpointSource_t   iSrc = BP_SRC_MEM_1;
-	BreakpointOperator_t iCmp = BP_OP_EQUAL  ;
+	return CmdBreakpointAddMem(nArgs);
+}
+//===========================================================================
+Update_t CmdBreakpointAddMemR(int nArgs)
+{
+	return CmdBreakpointAddMem(nArgs, BP_SRC_MEM_READ_ONLY);
+}
+//===========================================================================
+Update_t CmdBreakpointAddMemW(int nArgs)
+{
+	return CmdBreakpointAddMem(nArgs, BP_SRC_MEM_WRITE_ONLY);
+}
+//===========================================================================
+Update_t CmdBreakpointAddMem  (int nArgs, BreakpointSource_t bpSrc /*= BP_SRC_MEM_RW*/)
+{
+	BreakpointSource_t   iSrc = bpSrc;
+	BreakpointOperator_t iCmp = BP_OP_EQUAL;
 
 	int iArg = 0;
 	
@@ -1647,11 +1683,16 @@ void _BWZ_List( const Breakpoint_t * aBreakWatchZero, const int iBWZ ) //, bool
 		pSymbol = sName;
 	}
 
-	ConsoleBufferPushFormat( sText, "  #%d %c %04X %s",
+	char cBPM = aBreakWatchZero[iBWZ].eSource == BP_SRC_MEM_READ_ONLY ? 'R'
+				: aBreakWatchZero[iBWZ].eSource == BP_SRC_MEM_WRITE_ONLY ? 'W'
+				: ' ';
+
+	ConsoleBufferPushFormat( sText, "  #%d %c %04X %c %s",
 //		(bZeroBased ? iBWZ + 1 : iBWZ),
 		iBWZ,
 		sFlags[ (int) aBreakWatchZero[ iBWZ ].bEnabled ],
 		aBreakWatchZero[ iBWZ ].nAddress,
+		cBPM,
 		pSymbol
 	);
 }
@@ -8657,7 +8698,11 @@ void DebugContinueStepping ()
 			else if (g_bDebugBreakpointHit & BP_HIT_REG)
 				pszStopReason = TEXT("Register matches value");
 			else if (g_bDebugBreakpointHit & BP_HIT_MEM)
-				sprintf_s(szStopMessage, sizeof(szStopMessage), "Memory accessed at $%04X", g_uBreakMemoryAddress);
+				sprintf_s(szStopMessage, sizeof(szStopMessage), "Memory access at $%04X", g_uBreakMemoryAddress);
+			else if (g_bDebugBreakpointHit & BP_HIT_MEMW)
+				sprintf_s(szStopMessage, sizeof(szStopMessage), "Write access at $%04X", g_uBreakMemoryAddress);
+			else if (g_bDebugBreakpointHit & BP_HIT_MEMR)
+				sprintf_s(szStopMessage, sizeof(szStopMessage), "Read access at $%04X", g_uBreakMemoryAddress);
 			else if (g_bDebugBreakpointHit & BP_HIT_PC_READ_FLOATING_BUS_OR_IO_MEM)
 				pszStopReason = TEXT("PC reads from floating bus or I/O memory");
 			else
diff --git a/source/Debugger/Debug.h b/source/Debugger/Debug.h
index 8dc3f84d..1ec7b215 100644
--- a/source/Debugger/Debug.h
+++ b/source/Debugger/Debug.h
@@ -29,12 +29,14 @@
 // Breakpoints
 	enum BreakpointHit_t
 	{
-		BP_HIT_NONE     = 0
-		,BP_HIT_INVALID = (1 << 0)
-		,BP_HIT_OPCODE  = (1 << 1)
-		,BP_HIT_REG     = (1 << 2)
-		,BP_HIT_MEM     = (1 << 3)
-		,BP_HIT_PC_READ_FLOATING_BUS_OR_IO_MEM = (1 << 4)
+		BP_HIT_NONE = 0
+		, BP_HIT_INVALID = (1 << 0)
+		, BP_HIT_OPCODE = (1 << 1)
+		, BP_HIT_REG = (1 << 2)
+		, BP_HIT_MEM = (1 << 3)
+		, BP_HIT_MEMR = (1 << 4)
+		, BP_HIT_MEMW = (1 << 5)
+		, BP_HIT_PC_READ_FLOATING_BUS_OR_IO_MEM = (1 << 6)
 	};
 
 	extern int          g_nBreakpoints;
diff --git a/source/Debugger/DebugDefs.h b/source/Debugger/DebugDefs.h
index 8f85430d..d3b63581 100644
--- a/source/Debugger/DebugDefs.h
+++ b/source/Debugger/DebugDefs.h
@@ -10,3 +10,4 @@
 	const unsigned int _6502_BRK_VECTOR      = 0xFFFE;
 	const unsigned int _6502_MEM_BEGIN = 0x0000;
 	const unsigned int _6502_MEM_END   = 0xFFFF;
+	const unsigned int _6502_MEM_LEN   = _6502_MEM_END + 1;
diff --git a/source/Debugger/Debugger_Assembler.cpp b/source/Debugger/Debugger_Assembler.cpp
index 3fb211a6..350fa207 100644
--- a/source/Debugger/Debugger_Assembler.cpp
+++ b/source/Debugger/Debugger_Assembler.cpp
@@ -112,7 +112,7 @@ const Opcodes_t g_aOpcodes65C02[ NUM_OPCODES ] =
 	{"SEC", 0     ,  0}, {"AND", AM_AY , R_}, {"DEC", 0     ,  0}, {"nop", 0  , 0 }, // 38 .. 3B
 	{"BIT", AM_AX , R_}, {"AND", AM_AX , R_}, {"ROL", AM_AX , RW}, {"nop", 0  , 0 }, // 3C .. 3F
 
-	{"RTI", 0     ,  0}, {"EOR", AM_IZX, R_}, {"nop", AM_M  , im}, {"nop", 0  , 0 }, // 40 .. 43
+	{"RTI", 0     , SR}, {"EOR", AM_IZX, R_}, {"nop", AM_M  , im}, {"nop", 0  , 0 }, // 40 .. 43
 	{"nop", AM_Z  ,  0}, {"EOR", AM_Z  , R_}, {"LSR", AM_Z  , _W}, {"nop", 0  , 0 }, // 44 .. 47
 	{"PHA", 0     , SW}, {"EOR", AM_M  , im}, {"LSR", 0     ,  0}, {"nop", 0  , 0 }, // 48 .. 4B
 	{"JMP", AM_A  ,  0}, {"EOR", AM_A  , R_}, {"LSR", AM_A  , _W}, {"nop", 0  , 0 }, // 4C .. 4F
@@ -234,7 +234,7 @@ Fx	BEQ r  SBC (d),Y  sbc (z)  ---  ---      SBC d,X  INC z,X  ---  SED  SBC a,Y
 	{"SEC", 0     ,  0}, {"AND", AM_AY , R_}, {"nop", 0     ,  0}, {"rla", AM_AY , RW}, // 38 .. 3B
 	{"nop", AM_AX ,  0}, {"AND", AM_AX , R_}, {"ROL", AM_AX , RW}, {"rla", AM_AX , RW}, // 3C .. 3F
 
-	{"RTI", 0     ,  0}, {"EOR", AM_IZX, R_}, {"hlt", 0     ,  0}, {"lse", AM_IZX, RW}, // 40 .. 43
+	{"RTI", 0     , SR}, {"EOR", AM_IZX, R_}, {"hlt", 0     ,  0}, {"lse", AM_IZX, RW}, // 40 .. 43
 	{"nop", AM_Z  ,  0}, {"EOR", AM_Z  , R_}, {"LSR", AM_Z  , RW}, {"lse", AM_Z  , RW}, // 44 .. 47
 	{"PHA", 0     , SW}, {"EOR", AM_M  , im}, {"LSR", 0     ,  0}, {"alr", AM_M  , im}, // 48 .. 4B
 	{"JMP", AM_A  ,  0}, {"EOR", AM_A  , R_}, {"LSR", AM_A  , RW}, {"lse", AM_A  , RW}, // 4C .. 4F
diff --git a/source/Debugger/Debugger_Commands.cpp b/source/Debugger/Debugger_Commands.cpp
index f28cb050..a55ada30 100644
--- a/source/Debugger/Debugger_Commands.cpp
+++ b/source/Debugger/Debugger_Commands.cpp
@@ -85,7 +85,9 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 		{TEXT("BPR")         , CmdBreakpointAddReg  , CMD_BREAKPOINT_ADD_REG   , "Add breakpoint on register value"      }, // NOTE! Different from SoftICE !!!!
 		{TEXT("BPX")         , CmdBreakpointAddPC   , CMD_BREAKPOINT_ADD_PC    , "Add breakpoint at current instruction" },
 		{TEXT("BPIO")        , CmdBreakpointAddIO   , CMD_BREAKPOINT_ADD_IO    , "Add breakpoint for IO address $C0xx"   },
-		{TEXT("BPM")         , CmdBreakpointAddMem  , CMD_BREAKPOINT_ADD_MEM   , "Add breakpoint on memory access"       },  // SoftICE
+		{TEXT("BPM")         , CmdBreakpointAddMemA , CMD_BREAKPOINT_ADD_MEM   , "Add breakpoint on memory access"       },  // SoftICE
+		{TEXT("BPMR")        , CmdBreakpointAddMemR , CMD_BREAKPOINT_ADD_MEMR  , "Add breakpoint on memory read access"  },
+		{TEXT("BPMW")        , CmdBreakpointAddMemW , CMD_BREAKPOINT_ADD_MEMW  , "Add breakpoint on memory write access" },
 
 		{TEXT("BPC")         , CmdBreakpointClear   , CMD_BREAKPOINT_CLEAR     , "Clear (remove) breakpoint"             }, // SoftICE
 		{TEXT("BPD")         , CmdBreakpointDisable , CMD_BREAKPOINT_DISABLE   , "Disable breakpoint- it is still in the list, just not active" }, // SoftICE
diff --git a/source/Debugger/Debugger_Display.cpp b/source/Debugger/Debugger_Display.cpp
index d97ae25f..66fd81c8 100644
--- a/source/Debugger/Debugger_Display.cpp
+++ b/source/Debugger/Debugger_Display.cpp
@@ -1078,7 +1078,7 @@ void DrawBreakpoints ( int line )
 	for (iBreakpoint = 0; iBreakpoint < MAX_BREAKPOINTS; iBreakpoint++ )
 	{
 		Breakpoint_t *pBP = &g_aBreakpoints[iBreakpoint];
-		WORD nLength   = pBP->nLength;
+		UINT nLength = pBP->nLength;
 
 #if DEBUG_FORCE_DISPLAY
 		nLength = 2;
@@ -1179,6 +1179,14 @@ void DrawBreakpoints ( int line )
 			sprintf( sText, "%04X", nAddress1 );
 			PrintTextCursorX( sText, rect2 );
 
+			if (nLength == 1)
+			{
+				if (pBP->eSource == BP_SRC_MEM_READ_ONLY)
+					PrintTextCursorX("R", rect2);
+				else if (pBP->eSource == BP_SRC_MEM_WRITE_ONLY)
+					PrintTextCursorX("W", rect2);
+			}
+
 			if (nLength > 1)
 			{
 				DebuggerSetColorBG( DebuggerGetColor( BG_INFO ) );
@@ -1211,6 +1219,11 @@ void DrawBreakpoints ( int line )
 #endif
 				sprintf( sText, "%04X", nAddress2 );
 				PrintTextCursorX( sText, rect2 );
+
+				if (pBP->eSource == BP_SRC_MEM_READ_ONLY)
+					PrintTextCursorX("R", rect2);
+				else if (pBP->eSource == BP_SRC_MEM_WRITE_ONLY)
+					PrintTextCursorX("W", rect2);
 			}
 
 #if !USE_APPLE_FONT
diff --git a/source/Debugger/Debugger_Help.cpp b/source/Debugger/Debugger_Help.cpp
index 372bb9ba..be71b92d 100644
--- a/source/Debugger/Debugger_Help.cpp
+++ b/source/Debugger/Debugger_Help.cpp
@@ -1058,6 +1058,12 @@ Update_t CmdHelpSpecific (int nArgs)
 			break;
 		case CMD_BREAKPOINT_LIST:
 			break;
+		case CMD_BREAKPOINT_ADD_MEM:
+		case CMD_BREAKPOINT_ADD_MEMR:
+		case CMD_BREAKPOINT_ADD_MEMW:
+			ConsoleColorizePrint(sText, " Usage: <range>");
+			Help_Range();
+			break;
 	// Config - Load / Save
 		case CMD_CONFIG_LOAD:
 			ConsoleColorizePrint( sText, " Usage: [\"filename\"]" );
diff --git a/source/Debugger/Debugger_Types.h b/source/Debugger/Debugger_Types.h
index 87fa931c..952b7ab9 100644
--- a/source/Debugger/Debugger_Types.h
+++ b/source/Debugger/Debugger_Types.h
@@ -153,7 +153,7 @@
 			-    ?        no, not listed
 	*/
 	// NOTE: Order must match _PARAM_REGS_*
-	// NOTE: Order must match Breakpoint_Source_t
+	// NOTE: Order must match BreakpointSource_t
 	// NOTE: Order must match g_aBreakpointSource
 	enum BreakpointSource_t
 	{
@@ -175,7 +175,9 @@
 		BP_SRC_FLAG_N, // Sign
 
 		BP_SRC_OPCODE,
-		BP_SRC_MEM_1 ,
+		BP_SRC_MEM_RW,
+		BP_SRC_MEM_READ_ONLY,
+		BP_SRC_MEM_WRITE_ONLY,
 
 		NUM_BREAKPOINT_SOURCES
 	};
@@ -201,7 +203,7 @@
 	struct Breakpoint_t
 	{
 		WORD                 nAddress; // for registers, functions as nValue
-		WORD                 nLength ;
+		UINT                 nLength ;
 		BreakpointSource_t   eSource;
 		BreakpointOperator_t eOperator;
 		bool                 bSet    ; // used to be called enabled pre 2.0
@@ -323,6 +325,8 @@
 //		,	CMD_BREAKPOINT_EXEC = CMD_BREAKPOINT_ADD_ADDR // alias
 		, CMD_BREAKPOINT_ADD_IO  // break on: [$C000-$C7FF] Load/Store 
 		, CMD_BREAKPOINT_ADD_MEM // break on: [$0000-$FFFF], excluding IO
+		, CMD_BREAKPOINT_ADD_MEMR // break on read on: [$0000-$FFFF], excluding IO
+		, CMD_BREAKPOINT_ADD_MEMW // break on write on: [$0000-$FFFF], excluding IO
 
 		, CMD_BREAKPOINT_CLEAR
 //		,	CMD_BREAKPOINT_REMOVE = CMD_BREAKPOINT_CLEAR // alias
@@ -613,7 +617,10 @@
 	Update_t CmdBreakpointAddReg   (int nArgs);
 	Update_t CmdBreakpointAddPC    (int nArgs);
 	Update_t CmdBreakpointAddIO    (int nArgs);
-	Update_t CmdBreakpointAddMem   (int nArgs);
+	Update_t CmdBreakpointAddMem   (int nArgs, BreakpointSource_t bpSrc = BP_SRC_MEM_RW);
+	Update_t CmdBreakpointAddMemA  (int nArgs);
+	Update_t CmdBreakpointAddMemR  (int nArgs);
+	Update_t CmdBreakpointAddMemW  (int nArgs);
 	Update_t CmdBreakpointClear    (int nArgs);
 	Update_t CmdBreakpointDisable  (int nArgs);
 	Update_t CmdBreakpointEdit     (int nArgs);
@@ -1117,7 +1124,7 @@ const	DisasmData_t* pDisasmData; // If != NULL then bytes are marked up as data
 	extern const unsigned int _6502_BRK_VECTOR      ;//= 0xFFFE;
 	extern const unsigned int _6502_MEM_BEGIN       ;//= 0x0000;
 	extern const unsigned int _6502_MEM_END         ;//= 0xFFFF;
-
+	extern const unsigned int _6502_MEM_LEN			;//= 0x10000;
 
 	enum DEVICE_e
 	{
@@ -1301,7 +1308,7 @@ const	DisasmData_t* pDisasmData; // If != NULL then bytes are marked up as data
 
 //		, PARAM_SIZE  // TODO: used by FONT SIZE
 
-	// Note: Order must match Breakpoint_Source_t
+	// Note: Order must match BreakpointSource_t
 	, _PARAM_REGS_BEGIN = _PARAM_BREAKPOINT_END // Daisy Chain
 // Regs
 		, PARAM_REG_A = _PARAM_REGS_BEGIN