diff --git a/bus.cpp b/bus.cpp
index 5b90ac8..f6e27a2 100644
--- a/bus.cpp
+++ b/bus.cpp
@@ -305,7 +305,7 @@ uint16_t bus::read(const uint16_t a, const bool word_mode, const bool use_prev,
 
 	int run_mode = (c->getPSW() >> (use_prev ? 12 : 14)) & 3;
 
-	uint32_t m_offset = calculate_physical_address(run_mode, a, !peek_only);
+	uint32_t m_offset = calculate_physical_address(run_mode, a, !peek_only, false);
 
 	if (word_mode)
 		temp = m -> readByte(m_offset);
@@ -317,7 +317,7 @@ uint16_t bus::read(const uint16_t a, const bool word_mode, const bool use_prev,
 	return temp;
 }
 
-uint32_t bus::calculate_physical_address(const int run_mode, const uint16_t a, const bool trap_on_failure)
+uint32_t bus::calculate_physical_address(const int run_mode, const uint16_t a, const bool trap_on_failure, const bool is_write)
 {
 	uint32_t m_offset = 0;
 
@@ -331,11 +331,30 @@ uint32_t bus::calculate_physical_address(const int run_mode, const uint16_t a, c
 
 		m_offset += p_offset;
 
-		uint16_t pdr_len = (((pages[run_mode][0][apf].pdr >> 8) & 127) + 1) * 64;  // TODO: D/I
-
-		bool direction = pages[run_mode][0][apf].pdr & 8;  // TODO: D/I
-
 		if (trap_on_failure) {
+			int access_control = pages[run_mode][0][apf].pdr & 7;
+
+			if (is_write && access_control != 6) {  // write
+				c->schedule_trap(04);  // invalid address
+
+				pages[run_mode][0][apf].pdr |= 1 << 7;  // TODO: D/I
+
+				throw 1;
+			}
+			else if (!is_write) { // read
+				if (access_control == 0 || access_control == 1 || access_control == 3 || access_control == 4 || access_control == 7) {
+					c->schedule_trap(04);  // invalid address
+
+					pages[run_mode][0][apf].pdr |= 1 << 7;  // TODO: D/I
+
+					throw 1;
+				}
+			}
+
+			uint16_t pdr_len = (((pages[run_mode][0][apf].pdr >> 8) & 127) + 1) * 64;  // TODO: D/I
+
+			bool direction = pages[run_mode][0][apf].pdr & 8;  // TODO: D/I
+
 			if (m_offset >= n_pages * 8192) {
 				D(fprintf(stderr, "bus::calculate_physical_address %o >= %o\n", m_offset, n_pages * 8192);)
 				c->schedule_trap(04);  // invalid address
@@ -640,7 +659,7 @@ uint16_t bus::write(const uint16_t a, const bool word_mode, uint16_t value, cons
 
 	int run_mode = (c->getPSW() >> (use_prev ? 12 : 14)) & 3;
 
-	uint32_t m_offset = calculate_physical_address(run_mode, a, true);
+	uint32_t m_offset = calculate_physical_address(run_mode, a, true, true);
 
 	D(fprintf(stderr, "WRITE to %06o/%07o: %o\n", a, m_offset, value);)
 
diff --git a/bus.h b/bus.h
index 6d9a52a..4ba3ac9 100644
--- a/bus.h
+++ b/bus.h
@@ -77,5 +77,5 @@ public:
 
 	uint16_t get_switch_register() const { return switch_register; }
 
-	uint32_t calculate_physical_address(const int run_mode, const uint16_t a, const bool trap_on_failure);
+	uint32_t calculate_physical_address(const int run_mode, const uint16_t a, const bool trap_on_failure, const bool is_write);
 };
diff --git a/console.cpp b/console.cpp
index 07e63bf..fa54d1f 100644
--- a/console.cpp
+++ b/console.cpp
@@ -195,11 +195,13 @@ void console::operator()()
 		if (c == -1)
 			continue;
 
-		if (c == 3)  // ^c
+		bool running_flag = *get_running_flag();
+
+		if (running_flag == false && c == 3)  // ^c
 			*interrupt_emulation = *terminate = true;
-		else if (c == 5)  // ^e
+		else if (running_flag == true && c == 5)  // ^e
 			*interrupt_emulation = true;
-		else if (c == 12)  // ^l
+		else if (running_flag == false && c == 12)  // ^l
 			refresh_virtual_terminal();
 		else {
 			input_buffer.push_back(c);
diff --git a/console_ncurses.cpp b/console_ncurses.cpp
index 66735c4..9049a19 100644
--- a/console_ncurses.cpp
+++ b/console_ncurses.cpp
@@ -138,7 +138,7 @@ void console_ncurses::panel_update_thread()
 		int      run_mode      = current_PSW >> 14;
 
 		uint16_t current_PC    = c->getPC();
-		uint32_t full_addr     = b->calculate_physical_address(run_mode, current_PC, false);
+		uint32_t full_addr     = b->calculate_physical_address(run_mode, current_PC, false, false);
 
 		uint16_t current_instr = b->readWord(current_PC);
 
diff --git a/debugger.cpp b/debugger.cpp
index ddefb13..923b484 100644
--- a/debugger.cpp
+++ b/debugger.cpp
@@ -173,6 +173,8 @@ void debugger(console *const cnsl, bus *const b, std::atomic_bool *const interru
 
 		c->emulation_start();
 
+		*cnsl->get_running_flag() = true;
+
 		while(!event && !*interrupt_emulation) {
 			if (tracing || single_step)
 				disassemble(c, single_step ? cnsl : nullptr, c->getPC(), false);
@@ -188,6 +190,8 @@ void debugger(console *const cnsl, bus *const b, std::atomic_bool *const interru
 				break;
 		}
 
+		*cnsl->get_running_flag() = false;
+
 		if (!single_step) {
 			auto speed = c->get_mips_rel_speed();
 			cnsl->debug("MIPS: %.2f, relative speed: %.2f%%", speed.first, speed.second);
diff --git a/main.cpp b/main.cpp
index ba1610e..196953d 100644
--- a/main.cpp
+++ b/main.cpp
@@ -262,8 +262,6 @@ int main(int argc, char *argv[])
 	sigaction(SIGTERM, &sa, nullptr);
 	sigaction(SIGINT , &sa, nullptr);
 
-	*running = true;
-
 //	loadbin(b, 0, "test.dat");
 //	c->setRegister(7, 0);
 
@@ -274,6 +272,8 @@ int main(int argc, char *argv[])
 	else {
 		c->emulation_start();  // for statistics
 
+		*running = true;
+
 		while(!event) {
 			if (interrupt_emulation) {
 				if (terminate)
@@ -282,9 +282,9 @@ int main(int argc, char *argv[])
 
 			c->step();
 		}
-	}
 
-	*running = false;
+		*running = false;
+	}
 
 	terminate = true;