diff --git a/A2Mac.xcodeproj/project.xcworkspace/xcuserdata/trudnai.xcuserdatad/xcdebugger/Expressions.xcexplist b/A2Mac.xcodeproj/project.xcworkspace/xcuserdata/trudnai.xcuserdatad/xcdebugger/Expressions.xcexplist
index ec5ebce..ce10f13 100644
--- a/A2Mac.xcodeproj/project.xcworkspace/xcuserdata/trudnai.xcuserdatad/xcdebugger/Expressions.xcexplist
+++ b/A2Mac.xcodeproj/project.xcworkspace/xcuserdata/trudnai.xcuserdatad/xcdebugger/Expressions.xcexplist
@@ -1183,6 +1183,14 @@
             </PersistentString>
          </PersistentStrings>
       </ContextState>
+      <ContextState
+         contextName = "m6502_dbg_bp_del:6502_bp.c">
+         <PersistentStrings>
+            <PersistentString
+               value = "bp_idx">
+            </PersistentString>
+         </PersistentStrings>
+      </ContextState>
       <ContextState
          contextName = "AppDelegate.showPreferences(_:):AppDelegate.swift">
          <PersistentStrings>
diff --git a/A2Mac/DebuggerViewController.swift b/A2Mac/DebuggerViewController.swift
index 9ee292d..61610b9 100644
--- a/A2Mac/DebuggerViewController.swift
+++ b/A2Mac/DebuggerViewController.swift
@@ -328,6 +328,22 @@ N V - B D I Z C
     }
 
 
+    func convertMouseCoordinates(scrollView : NSView, display : NSTextView, mouseLocation : NSPoint) -> NSPoint {
+        var location = mouseLocation
+        let parent_frame = scrollView.superview?.frame
+
+//        let minX = parent_frame!.minX + scrollView.frame.minX
+        let minY = parent_frame!.minY + scrollView.frame.minY
+//        let maxX = minX + scrollView.frame.width
+        let maxY = minY + scrollView.frame.height
+
+//        location.x = maxX - location.x
+        location.y = maxY - location.y + display.visibleRect.origin.y
+
+        return location
+    }
+
+
     func highlightCursor(scrollView : NSView, display : NSTextView, mouseLocation : NSPoint) {
         var location = mouseLocation
         let parent_frame = scrollView.superview?.frame
@@ -339,7 +355,7 @@ N V - B D I Z C
 
         if location.x > minX && location.x < maxX
         && location.y > minY && location.y < maxY {
-            location.x = maxX - location.x
+//            location.x = maxX - location.x
             location.y = maxY - location.y + display.visibleRect.origin.y
 
             let line = getLine(inView: display, forY: location.y)
@@ -351,19 +367,50 @@ N V - B D I Z C
     }
 
 
+    // select disassembly line
     override func mouseDown(with event: NSEvent) {
+        let location = convertMouseCoordinates(scrollView: Disass_Scroll, display: Disass_Display, mouseLocation: event.locationInWindow)
+
+        if location.x < 30 {
+            let line = getLine(inView: Disass_Display, forY: location.y)
+            let addr = getAddr(forLine: line)
+
+            if m6502_dbg_bp_is_exists(addr) {
+                m6502_dbg_bp_del(addr)
+            }
+            else {
+                m6502_dbg_bp_add(addr)
+            }
+
+            // force regenerate disassembly
+            disass_addr = 0xFFFF
+            DisplayDisassembly()
+//            scroll_to(view: Disass_Display, line: line)
+        }
+        else {
+            highlightCursor(scrollView: Disass_Scroll, display: Disass_Display, mouseLocation: location)
+        }
+    }
+
+
+    // context menu
+    override func rightMouseDown(with event: NSEvent) {
         let location = event.locationInWindow
         highlightCursor(scrollView: Disass_Scroll, display: Disass_Display, mouseLocation: location)
     }
 
-//    override func mouseMoved(with event: NSEvent) {
-//        let location = event.locationInWindow
-//        highlightCursor(scrollView: Disass_Scroll, display: Disass_Display, mouseLocation: location)
-//    }
-
 
     var addr_line = [UInt16 : Int]()
 
+    func getLine(forAddr: UInt16) -> Int {
+        return addr_line[forAddr] ?? 0
+    }
+
+    func getAddr(forLine: Int) -> UInt16 {
+        return addr_line.first(where: { $1 == forLine })?.key ?? 0
+    }
+
+
     func DisplayDisassembly() {
         let m6502_saved = m6502
         var disass = ""
@@ -378,7 +425,7 @@ N V - B D I Z C
         // TODO: Also check if memory area updated!
 
         var need_disass = m6502.PC < disass_addr || m6502.PC > disass_addr + disass_addr_max
-        line_number_at_PC = addr_line[m6502_saved.PC] ?? 0
+        line_number_at_PC = getLine(forAddr: m6502_saved.PC)
 
 //        if m6502.PC > disass_addr && m6502.PC < disass_addr + disass_addr_max {
         if line_number_at_PC != 0 && !need_disass {
diff --git a/A2Mac/DisassView.swift b/A2Mac/DisassView.swift
index 1034d73..7b0e140 100644
--- a/A2Mac/DisassView.swift
+++ b/A2Mac/DisassView.swift
@@ -58,30 +58,30 @@ class DisassView: NSTextView {
         // debugDisplayContraints()
     }
 
-    override func mouseUp(with event: NSEvent) {
-        //        print(#function + "DisassView")
-        DebuggerViewController.shared?.mouseUp(with: event)
-    }
+//    override func mouseUp(with event: NSEvent) {
+//        //        print(#function + "DisassView")
+//        DebuggerViewController.shared?.mouseUp(with: event)
+//    }
 
     override func rightMouseDown(with event: NSEvent) {
         //        print(#function + "DisassView")
         DebuggerViewController.shared?.rightMouseDown(with: event)
     }
 
-    override func rightMouseUp(with event: NSEvent) {
-        //        print(#function + "DisassView")
-        DebuggerViewController.shared?.rightMouseUp(with: event)
-    }
+//    override func rightMouseUp(with event: NSEvent) {
+//        //        print(#function + "DisassView")
+//        DebuggerViewController.shared?.rightMouseUp(with: event)
+//    }
 
-    override func otherMouseDown(with event: NSEvent) {
-        //        print(#function + "DisassView")
-        DebuggerViewController.shared?.otherMouseDown(with: event)
-    }
-
-    override func otherMouseUp(with event: NSEvent) {
-        //        print(#function + "DisassView")
-        DebuggerViewController.shared?.otherMouseUp(with: event)
-    }
+//    override func otherMouseDown(with event: NSEvent) {
+//        //        print(#function + "DisassView")
+//        DebuggerViewController.shared?.otherMouseDown(with: event)
+//    }
+//
+//    override func otherMouseUp(with event: NSEvent) {
+//        //        print(#function + "DisassView")
+//        DebuggerViewController.shared?.otherMouseUp(with: event)
+//    }
 
 }
 
diff --git a/src/cpu/6502.c b/src/cpu/6502.c
index ab90a8f..31e359d 100644
--- a/src/cpu/6502.c
+++ b/src/cpu/6502.c
@@ -419,7 +419,7 @@ void m6502_Run() {
 
 void m6502_Debug(void) {
     m6502.clktime += m6502.clkfrm;
-    m6502.clkfrm = 0;
+//    m6502.clkfrm = 0;
     m6502.lastIO = 0;
     m6502.interrupt = NO_INT; // TODO: This should be taken care by the interrupt handler
 
@@ -436,14 +436,9 @@ void m6502_Debug(void) {
         }
     }
 
-    if ( m6502_dbg_bp_is_exists(m6502.PC) ) {
-        cpuState = cpuState_halted;
-        m6502.debugger.wMask = 0;
-        m6502.debugger.on = 0;
-        return;
-    }
+    clk_6502_per_frm_max = clk_6502_per_frm;
 
-    for ( clk_6502_per_frm_max = clk_6502_per_frm; m6502.clkfrm < clk_6502_per_frm_max ; m6502.clkfrm += m6502_Step() ) {
+    for ( m6502.clkfrm = m6502_Step(); m6502.clkfrm < clk_6502_per_frm_max ; m6502.clkfrm += m6502_Step() ) {
         switch (m6502.interrupt) {
             case HALT:
                 if (m6502.debugger.mask.hlt) {
@@ -514,6 +509,14 @@ void m6502_Debug(void) {
         }
 
         m6502.interrupt = NO_INT;
+
+        if ( m6502_dbg_bp_is_exists(m6502.PC) ) {
+            cpuState = cpuState_halted;
+            m6502.debugger.wMask = 0;
+            m6502.debugger.on = 0;
+            return;
+        }
+
     }
 
 }
diff --git a/src/cpu/6502_bp.c b/src/cpu/6502_bp.c
index bff4aa8..ac9f557 100644
--- a/src/cpu/6502_bp.c
+++ b/src/cpu/6502_bp.c
@@ -77,11 +77,11 @@ uint16_t m6502_dbg_bp_get_first() {
 /// m6502_dbg_bp_get_first
 /// Get first valid BP
 /// @return addr of BP or 0 if non
-uint16_t m6502_dbg_bp_is_exists(uint16_t addr) {
+_Bool m6502_dbg_bp_is_exists(uint16_t addr) {
     for (uint16_t bp = m6502_dbg_bp_get_first(); bp; bp = m6502_dbg_bp_get_next()) {
         if ( bp == addr) {
             // found it!
-            return bp;
+            return 1;
         }
     }
     return 0;
@@ -103,16 +103,26 @@ int m6502_dbg_bp_add(uint16_t addr) {
 }
 
 
-void m6502_dbg_bp_init(void) {
+/// m6502_dbg_bp_del
+/// Remove a breakpoint
+/// @param addr address to remove
+void m6502_dbg_bp_del(uint16_t addr) {
+    for (uint16_t bp = m6502_dbg_bp_get_first(); bp; bp = m6502_dbg_bp_get_next()) {
+        if ( bp == addr ) {
+            breakpoints[bp_idx] = 0;
+        }
+    }
+}
+
+
+void m6502_dbg_bp_del_all(void) {
     bp_idx = 0;
     memset(breakpoints, 0, sizeof(breakpoints));
-
-    m6502_dbg_bp_add(0xC28B); // keyin DOS 3.3
 }
 
 
 void m6502_dbg_init(void) {
-    m6502_dbg_bp_init();
+    m6502_dbg_bp_del_all();
 }
 
 
diff --git a/src/cpu/6502_bp.h b/src/cpu/6502_bp.h
index 5e6ba8f..e5f1dd0 100644
--- a/src/cpu/6502_bp.h
+++ b/src/cpu/6502_bp.h
@@ -16,7 +16,9 @@ extern uint16_t breakpoints[DEBUG_MAX_BREAKPOINTS];
 
 extern void m6502_dbg_init(void);
 extern int m6502_dbg_bp_add(uint16_t addr);
-extern uint16_t m6502_dbg_bp_is_exists(uint16_t addr);
+extern void m6502_dbg_bp_del(uint16_t addr);
+extern void m6502_dbg_bp_del_all(void);
+extern _Bool m6502_dbg_bp_is_exists(uint16_t addr);
 
 
 #endif /* _6502_bp_h */