diff --git a/bus.cpp b/bus.cpp
index 8198ae3..b19807c 100644
--- a/bus.cpp
+++ b/bus.cpp
@@ -8,6 +8,7 @@
 #include "bus.h"
 #include "gen.h"
 #include "cpu.h"
+#include "kw11-l.h"
 #include "log.h"
 #include "memory.h"
 #include "mmu.h"
@@ -26,15 +27,14 @@ bus::bus()
 
 	mmu_ = new mmu();
 
-	reset();
+	kw11_l_ = new kw11_l(this);
 
-#if defined(BUILD_FOR_RP2040)
-	xSemaphoreGive(lf_csr_lock);  // initialize
-#endif
+	reset();
 }
 
 bus::~bus()
 {
+	delete kw11_l_;
 	delete c;
 	delete tm11;
 	delete rk05_;
@@ -220,22 +220,8 @@ uint16_t bus::read(const uint16_t addr_in, const word_mode_t word_mode, const rm
 			return temp;
 		}
 
-		if (a == ADDR_LFC) { // line frequency clock and status register
-#if defined(BUILD_FOR_RP2040)
-			xSemaphoreTake(lf_csr_lock, portMAX_DELAY);
-#else
-			std::unique_lock<std::mutex> lck(lf_csr_lock);
-#endif
-
-			uint16_t temp = lf_csr;
-			if (!peek_only) DOLOG(debug, false, "READ-I/O line frequency clock: %o", temp);
-
-#if defined(BUILD_FOR_RP2040)
-			xSemaphoreGive(lf_csr_lock);
-#endif
-
-			return temp;
-		}
+		if (a == ADDR_LFC) // line frequency clock and status register
+			return kw11_l_->readWord(a);
 
 		if (a == ADDR_LP11CSR) { // printer, CSR register, LP11
 			uint16_t temp = 0x80;
@@ -848,17 +834,8 @@ write_rc_t bus::write(const uint16_t addr_in, const word_mode_t word_mode, uint1
 		}
 
 		if (a == ADDR_LFC) { // line frequency clock and status register
-#if defined(BUILD_FOR_RP2040)
-			xSemaphoreTake(lf_csr_lock, portMAX_DELAY);
-#else
-			std::unique_lock<std::mutex> lck(lf_csr_lock);
-#endif
+			kw11_l_->writeWord(a, value);
 
-			DOLOG(debug, false, "WRITE-I/O set line frequency clock/status register: %06o", value);
-			lf_csr = value;
-#if defined(BUILD_FOR_RP2040)
-			xSemaphoreGive(lf_csr_lock);
-#endif
 			return { false };
 		}
 
@@ -1023,35 +1000,3 @@ void bus::writeUnibusByte(const uint32_t a, const uint8_t v)
 	DOLOG(debug, false, "writeUnibusByte[%08o]=%03o", a, v);
 	m->writeByte(a, v);
 }
-
-void bus::set_lf_crs_b7()
-{
-#if defined(BUILD_FOR_RP2040)
-	xSemaphoreTake(lf_csr_lock, portMAX_DELAY);
-#else
-	std::unique_lock<std::mutex> lck(lf_csr_lock);
-#endif
-
-	lf_csr |= 128;
-
-#if defined(BUILD_FOR_RP2040)
-	xSemaphoreGive(lf_csr_lock);
-#endif
-}
-
-uint8_t bus::get_lf_crs()
-{
-#if defined(BUILD_FOR_RP2040)
-	xSemaphoreTake(lf_csr_lock, portMAX_DELAY);
-#else
-	std::unique_lock<std::mutex> lck(lf_csr_lock);
-#endif
-
-	uint8_t rc = lf_csr;
-
-#if defined(BUILD_FOR_RP2040)
-	xSemaphoreGive(lf_csr_lock);
-#endif
-
-	return rc;
-}
diff --git a/bus.h b/bus.h
index e61243a..1065d03 100644
--- a/bus.h
+++ b/bus.h
@@ -54,6 +54,7 @@
 #define ADDR_SYSTEM_ID 0177764
 
 class cpu;
+class kw11_l;
 class memory;
 class tty;
 
@@ -75,23 +76,17 @@ typedef struct {
 class bus
 {
 private:
-	cpu     *c     { nullptr };
-	tm_11   *tm11  { nullptr };
-	rk05    *rk05_ { nullptr };
-	rl02    *rl02_ { nullptr };
-	tty     *tty_  { nullptr };
+	cpu     *c       { nullptr };
+	tm_11   *tm11    { nullptr };
+	rk05    *rk05_   { nullptr };
+	rl02    *rl02_   { nullptr };
+	tty     *tty_    { nullptr };
+	kw11_l  *kw11_l_ { nullptr };
 
-	mmu     *mmu_  { nullptr };
+	mmu     *mmu_    { nullptr };
 
 	int      n_pages { DEFAULT_N_PAGES };
-	memory  *m     { nullptr };
-
-#if defined(BUILD_FOR_RP2040)
-	SemaphoreHandle_t lf_csr_lock { xSemaphoreCreateBinary() };
-#else
-	std::mutex lf_csr_lock;
-#endif
-	uint16_t   lf_csr { 0 };
+	memory  *m       { nullptr };
 
 	uint16_t microprogram_break_register { 0 };
 
@@ -103,35 +98,29 @@ public:
 	~bus();
 
 	void reset();
+	void init();  // invoked by 'RESET' command
 
 	void set_console_switches(const uint16_t new_state) { console_switches = new_state; }
 	void set_console_switch(const int bit, const bool state) { console_switches &= ~(1 << bit); console_switches |= state << bit; }
 	uint16_t get_console_switches() { return console_switches; }
 	void set_debug_mode() { console_switches |= 128; }
+	uint16_t get_console_leds() { return console_leds; }
 
 	int  get_memory_size() const { return n_pages; }
 	void set_memory_size(const int n_pages);
 
 	void mmudebug(const uint16_t a);
 
-	uint16_t get_console_leds() { return console_leds; }
+	void add_cpu (cpu   *const c    );
+	void add_tm11(tm_11 *const tm11 );
+	void add_rk05(rk05  *const rk05_);
+	void add_rl02(rl02  *const rl02_);
+	void add_tty (tty   *const tty_ );
 
-	void add_cpu (cpu *const c);
-	void add_tm11(tm_11 *const tm11);
-	void add_rk05(rk05 *const rk05_);
-	void add_rl02(rl02 *const rl02_);
-	void add_tty (tty *const tty_);
-
-	cpu *getCpu() { return c; }
-
-	tty *getTty() { return tty_; }
-
-	mmu *getMMU() { return mmu_; }
-
-	void init();  // invoked by 'RESET' command
-
-	void    set_lf_crs_b7();
-	uint8_t get_lf_crs();
+	cpu    *getCpu()    { return c;       }
+	kw11_l *getKW11_L() { return kw11_l_; }
+	tty    *getTty()    { return tty_;    }
+	mmu    *getMMU()    { return mmu_;    }
 
 	uint16_t read    (const uint16_t a, const word_mode_t word_mode, const rm_selection_t mode_selection, const bool peek_only=false, const d_i_space_t s = i_space);
 	uint16_t readByte(const uint16_t a) { return read(a, wm_byte, rm_cur); }
diff --git a/kw11-l.cpp b/kw11-l.cpp
index 9081eb3..449bfb2 100644
--- a/kw11-l.cpp
+++ b/kw11-l.cpp
@@ -25,13 +25,8 @@ void thread_wrapper_kw11(void *p)
 }
 #endif
 
-kw11_l::kw11_l(bus *const b, console *const cnsl) : b(b), cnsl(cnsl)
+kw11_l::kw11_l(bus *const b): b(b)
 {
-#if defined(ESP32) || defined(BUILD_FOR_RP2040)
-	xTaskCreate(&thread_wrapper_kw11, "kw11-l", 2048, this, 1, nullptr);
-#else
-	th = new std::thread(std::ref(*this));
-#endif
 }
 
 kw11_l::~kw11_l()
@@ -39,9 +34,26 @@ kw11_l::~kw11_l()
 	stop_flag = true;
 
 #if !defined(ESP32) && !defined(BUILD_FOR_RP2040)
-	th->join();
+	if (th) {
+		th->join();
 
-	delete th;
+		delete th;
+	}
+#endif
+}
+
+void kw11_l::begin(console *const cnsl)
+{
+	this->cnsl = cnsl;
+
+#if defined(ESP32) || defined(BUILD_FOR_RP2040)
+	xTaskCreate(&thread_wrapper_kw11, "kw11-l", 2048, this, 1, nullptr);
+
+#if defined(BUILD_FOR_RP2040)
+	xSemaphoreGive(lf_csr_lock);  // initialize
+#endif
+#else
+	th = new std::thread(std::ref(*this));
 #endif
 }
 
@@ -53,9 +65,9 @@ void kw11_l::operator()()
 
 	while(!stop_flag) {
 		if (*cnsl->get_running_flag()) {
-			b->set_lf_crs_b7();
+			set_lf_crs_b7();
  
-			if (b->get_lf_crs() & 64)
+			if (get_lf_crs() & 64)
 				b->getCpu()->queue_interrupt(6, 0100);
 
 			// TODO: dependant on cpu cycles processed
@@ -68,3 +80,77 @@ void kw11_l::operator()()
 
 	DOLOG(debug, true, "KW11-L thread terminating");
 }
+
+uint16_t kw11_l::readWord(const uint16_t a)
+{
+	if (a != ADDR_LFC) {
+		DOLOG(debug, true, "KW11-L readWord not for us (%06o)", a);
+		return 0;
+	}
+
+#if defined(BUILD_FOR_RP2040)
+	xSemaphoreTake(lf_csr_lock, portMAX_DELAY);
+#else
+	std::unique_lock<std::mutex> lck(lf_csr_lock);
+#endif
+
+	uint16_t temp = lf_csr;
+
+#if defined(BUILD_FOR_RP2040)
+       	xSemaphoreGive(lf_csr_lock);
+#endif
+
+	return temp;
+}
+
+void kw11_l::writeWord(const uint16_t a, const uint16_t value)
+{
+	if (a != ADDR_LFC) {
+		DOLOG(debug, true, "KW11-L writeWord not for us (%06o to %06o)", value, a);
+		return;
+	}
+
+#if defined(BUILD_FOR_RP2040)
+	xSemaphoreTake(lf_csr_lock, portMAX_DELAY);
+#else
+	std::unique_lock<std::mutex> lck(lf_csr_lock);
+#endif
+
+	DOLOG(debug, false, "WRITE-I/O set line frequency clock/status register: %06o", value);
+	lf_csr = value;
+#if defined(BUILD_FOR_RP2040)
+	xSemaphoreGive(lf_csr_lock);
+#endif
+}
+
+void kw11_l::set_lf_crs_b7()
+{
+#if defined(BUILD_FOR_RP2040)
+	xSemaphoreTake(lf_csr_lock, portMAX_DELAY);
+#else
+	std::unique_lock<std::mutex> lck(lf_csr_lock);
+#endif
+
+	lf_csr |= 128;
+
+#if defined(BUILD_FOR_RP2040)
+	xSemaphoreGive(lf_csr_lock);
+#endif
+}
+
+uint8_t kw11_l::get_lf_crs()
+{
+#if defined(BUILD_FOR_RP2040)
+	xSemaphoreTake(lf_csr_lock, portMAX_DELAY);
+#else
+	std::unique_lock<std::mutex> lck(lf_csr_lock);
+#endif
+
+	uint8_t rc = lf_csr;
+
+#if defined(BUILD_FOR_RP2040)
+	xSemaphoreGive(lf_csr_lock);
+#endif
+
+	return rc;
+}
diff --git a/kw11-l.h b/kw11-l.h
index 416f1f7..666ac40 100644
--- a/kw11-l.h
+++ b/kw11-l.h
@@ -1,26 +1,39 @@
-// (C) 2018-2023 by Folkert van Heusden
+// (C) 2018-2024 by Folkert van Heusden
 // Released under MIT license
 
 #include <atomic>
 #include <thread>
 
 #include "bus.h"
+#include "console.h"
 
 
 class kw11_l
 {
 private:
-	bus         *const b         { nullptr };
-	console     *const cnsl      { nullptr };
+	bus         *const b          { nullptr };
+	console           *cnsl       { nullptr };
 
-#if !defined(BUILD_FOR_RP2040)
-	std::thread *      th        { nullptr };
+#if defined(BUILD_FOR_RP2040)
+	SemaphoreHandle_t lf_csr_lock { xSemaphoreCreateBinary() };
+#else
+	std::thread       *th         { nullptr };
+	std::mutex         lf_csr_lock;
 #endif
-	std::atomic_bool   stop_flag { false };
+	uint16_t           lf_csr     { 0       };
+
+	std::atomic_bool   stop_flag  { false   };
+
+	uint8_t  get_lf_crs();
+	void     set_lf_crs_b7();
 
 public:
-	kw11_l(bus *const b, console *const cnsl);
+	kw11_l(bus *const b);
 	virtual ~kw11_l();
 
-	void operator()();
+	void     begin(console *const cnsl);
+	void     operator()();
+
+	uint16_t readWord (const uint16_t a);
+	void     writeWord(const uint16_t a, const uint16_t v);
 };
diff --git a/main.cpp b/main.cpp
index 71fa638..e36e4e9 100644
--- a/main.cpp
+++ b/main.cpp
@@ -584,14 +584,14 @@ int main(int argc, char *argv[])
 	if (test.empty() == false)
 		load_p11_x11(b, test);
 
-	kw11_l *lf = new kw11_l(b, cnsl);
-
 	std::thread *metrics_thread = nullptr;
 	if (metrics)
 		metrics_thread = new std::thread(get_metrics, c);
 
 	cnsl->start_thread();
 
+	b->getKW11_L()->begin(cnsl);
+
 	if (is_bic)
 		run_bic(cnsl, b, &event, tracing, bic_start.value());
 	else if (run_debugger || (bootloader == BL_NONE && test.empty() && tape.empty()))
@@ -624,11 +624,11 @@ int main(int argc, char *argv[])
 		delete metrics_thread;
 	}
 
-	delete lf;
-
-	delete cnsl;
+	cnsl->stop_thread();
 
 	delete b;
 
+	delete cnsl;
+
 	return 0;
 }