diff --git a/bus.cpp b/bus.cpp
index c69d1dd..3af1f5f 100644
--- a/bus.cpp
+++ b/bus.cpp
@@ -43,7 +43,7 @@ bus::~bus()
 }
 
 #if IS_POSIX
-json_t *bus::serialize()
+json_t *bus::serialize() const
 {
 	json_t *j_out = json_object();
 
@@ -59,12 +59,15 @@ json_t *bus::serialize()
 	if (mmu_)
 		json_object_set(j_out, "mmu", mmu_->serialize());
 
-	// TODO: cpu, rl02, rk05, tm11
+	if (c)
+		json_object_set(j_out, "cpu", c->serialize());
+
+	// TODO: rl02, rk05, tm11
 
 	return j_out;
 }
 
-bus *bus::deserialize(const json_t *const j, console *const cnsl)
+bus *bus::deserialize(const json_t *const j, console *const cnsl, std::atomic_uint32_t *const event)
 {
 	bus *b = new bus();
 
@@ -94,7 +97,13 @@ bus *bus::deserialize(const json_t *const j, console *const cnsl)
 		b->add_mmu(mmu_);
 	}
 
-	// TODO: mmu, cpu, rl02, rk05, tm11
+	temp = json_object_get(j, "cpu");
+	if (temp) {
+		cpu *cpu_ = cpu::deserialize(temp, b, event);
+		b->add_cpu(cpu_);
+	}
+
+	// TODO: rl02, rk05, tm11
 
 	return b;
 }
diff --git a/bus.h b/bus.h
index d1312ba..b0ae4c8 100644
--- a/bus.h
+++ b/bus.h
@@ -91,8 +91,8 @@ public:
 	~bus();
 
 #if IS_POSIX
-	json_t *serialize();
-	static bus *deserialize(const json_t *const j, console *const cnsl);
+	json_t *serialize() const;
+	static bus *deserialize(const json_t *const j, console *const cnsl, std::atomic_uint32_t *const event);
 #endif
 
 	void reset();
diff --git a/cpu.cpp b/cpu.cpp
index d5e9582..8f55edd 100644
--- a/cpu.cpp
+++ b/cpu.cpp
@@ -2395,3 +2395,66 @@ void cpu::step()
 		DOLOG(debug, false, "bus-trap during execution of command (%d)", exception_nr);
 	}
 }
+
+#if IS_POSIX
+json_t *cpu::serialize()
+{
+	json_t *j = json_object();
+
+	for(int set=0; set<2; set++) {
+		for(int regnr=0; regnr<6; regnr++)
+			json_object_set(j, format("register-%d-%d", set, regnr).c_str(), json_integer(regs0_5[set][regnr]));
+	}
+
+	for(int spnr=0; spnr<4; spnr++)
+		json_object_set(j, format("sp-%d", spnr).c_str(), json_integer(sp[spnr]));
+
+        json_object_set(j, "pc", json_integer(pc));
+        json_object_set(j, "instruction_start", json_integer(instruction_start));
+        json_object_set(j, "psw", json_integer(psw));
+        json_object_set(j, "fpsr", json_integer(fpsr));
+        json_object_set(j, "stackLimitRegister", json_integer(stackLimitRegister));
+        json_object_set(j, "processing_trap_depth", json_integer(processing_trap_depth));
+        json_object_set(j, "instruction_count", json_integer(instruction_count));
+        json_object_set(j, "running_since", json_integer(running_since));
+        json_object_set(j, "wait_time", json_integer(wait_time));
+        json_object_set(j, "it_is_a_trap", json_boolean(it_is_a_trap));
+        json_object_set(j, "debug_mode", json_boolean(debug_mode));
+	if (trap_delay.has_value())
+		json_object_set(j, "trap_delay", json_integer(trap_delay.value()));
+
+	return j;
+}
+
+cpu *cpu::deserialize(const json_t *const j, bus *const b, std::atomic_uint32_t *const event)
+{
+	cpu *c = new cpu(b, event);
+
+	for(int set=0; set<2; set++) {
+		for(int regnr=0; regnr<6; regnr++)
+			c->regs0_5[set][regnr] = json_integer_value(json_object_get(j, format("register-%d-%d", set, regnr).c_str()));
+	}
+
+	for(int spnr=0; spnr<4; spnr++)
+		c->sp[spnr] = json_integer_value(json_object_get(j, format("sp-%d", spnr).c_str()));
+
+        c->pc                    = json_integer_value(json_object_get(j, "pc"));
+        c->instruction_start     = json_integer_value(json_object_get(j, "instruction_start"));
+        c->psw                   = json_integer_value(json_object_get(j, "psw"));
+        c->fpsr                  = json_integer_value(json_object_get(j, "fpsr"));
+        c->stackLimitRegister    = json_integer_value(json_object_get(j, "stackLimitRegister"));
+        c->processing_trap_depth = json_integer_value(json_object_get(j, "processing_trap_depth"));
+        c->instruction_count     = json_integer_value(json_object_get(j, "instruction_count"));
+        c->running_since         = get_us();
+        c->wait_time             = 0;
+        c->it_is_a_trap          = json_boolean_value(json_object_get(j, "it_is_a_trap"));
+        c->debug_mode            = json_boolean_value(json_object_get(j, "debug_mode"));
+	json_t *temp = json_object_get(j, "trap_delay");
+	if (temp)
+		c->trap_delay    = json_integer_value(temp);
+	else
+		c->trap_delay.reset();
+
+	return c;
+}
+#endif
diff --git a/cpu.h b/cpu.h
index c968ca2..e5aeab4 100644
--- a/cpu.h
+++ b/cpu.h
@@ -14,6 +14,7 @@
 
 #include "breakpoint.h"
 #include "bus.h"
+#include "gen.h"
 
 
 constexpr const int initial_trap_delay   = 8;
@@ -111,6 +112,11 @@ public:
 	explicit cpu(bus *const b, std::atomic_uint32_t *const event);
 	~cpu();
 
+#if IS_POSIX
+	json_t *serialize();
+	static cpu *deserialize(const json_t *const j, bus *const b, std::atomic_uint32_t *const event);
+#endif
+
 	std::optional<std::string> check_breakpoint();
 	int set_breakpoint(breakpoint *const bp);
 	bool remove_breakpoint(const int bp_id);
diff --git a/debugger.cpp b/debugger.cpp
index 7c50e2c..378f75c 100644
--- a/debugger.cpp
+++ b/debugger.cpp
@@ -722,6 +722,25 @@ void show_queued_interrupts(console *const cnsl, cpu *const c)
 	}
 }
 
+void serialize_state(console *const cnsl, const bus *const b, const std::string & filename)
+{
+	json_t *j = b->serialize();
+
+	bool ok = false;
+
+	FILE *fh = fopen(filename.c_str(), "w");
+	if (fh) {
+		if (json_dumpf(j, fh, 0) == 0)
+			ok = true;
+
+		fclose(fh);
+	}
+
+	json_decref(j);
+
+	cnsl->put_string_lf(format("Serialize to %s: %s", filename.c_str(), ok ? "OK" : "failed"));
+}
+
 void debugger(console *const cnsl, bus *const b, std::atomic_uint32_t *const stop_event, const bool tracing_in)
 {
 	int32_t trace_start_addr = -1;
@@ -1069,6 +1088,10 @@ void debugger(console *const cnsl, bus *const b, std::atomic_uint32_t *const sto
 
 				continue;
 			}
+			else if (parts[0] == "ser" && parts.size() == 2) {
+				serialize_state(cnsl, b, parts.at(1));
+				continue;
+			}
 			else if (parts[0] == "setsl" && parts.size() == 3) {
 				setloghost(parts.at(1).c_str(), parse_ll(parts[2]));
 
@@ -1130,6 +1153,10 @@ void debugger(console *const cnsl, bus *const b, std::atomic_uint32_t *const sto
 					"stats         - show run statistics",
 					"ramsize       - set ram size (page count (8 kB))",
 					"bl            - set bootload (rl02 or rk05)",
+#if IS_POSIX
+					"ser           - serialize state to a file",
+					"dser          - deserialize state from a file",
+#endif
 #if defined(ESP32)
 					"cfgnet        - configure network (e.g. WiFi)",
 					"startnet      - start network",
diff --git a/memory.cpp b/memory.cpp
index 9761814..ed6b3f5 100644
--- a/memory.cpp
+++ b/memory.cpp
@@ -29,7 +29,7 @@ void memory::reset()
 }
 
 #if IS_POSIX
-json_t *memory::serialize()
+json_t *memory::serialize() const
 {
 	json_t *j = json_object();
 
@@ -50,7 +50,7 @@ memory *memory::deserialize(const json_t *const j)
 
 	json_t *ja   = json_object_get(j, "contents");
 	for(size_t i=0; i<size; i++)
-		m->writeByte(i, json_integer_value(json_array_get(ja, i)));
+		m->m[i] = json_integer_value(json_array_get(ja, i));
 
 	return m;
 }
diff --git a/memory.h b/memory.h
index 265b805..1a5dcbc 100644
--- a/memory.h
+++ b/memory.h
@@ -20,7 +20,7 @@ public:
 
 	void reset();
 #if IS_POSIX
-	json_t *serialize();
+	json_t *serialize() const;
 	static memory *deserialize(const json_t *const j);
 #endif
 
diff --git a/mmu.cpp b/mmu.cpp
index f3eaa7e..5e42949 100644
--- a/mmu.cpp
+++ b/mmu.cpp
@@ -222,7 +222,7 @@ void mmu::writeByte(const uint16_t a, const uint8_t value)
 }
 
 #if IS_POSIX
-void mmu::add_par_pdr(json_t *const target, const int run_mode, const bool is_d, const std::string & name)
+void mmu::add_par_pdr(json_t *const target, const int run_mode, const bool is_d, const std::string & name) const
 {
 	json_t *j = json_object();
 
@@ -239,7 +239,7 @@ void mmu::add_par_pdr(json_t *const target, const int run_mode, const bool is_d,
 	json_object_set(target, name.c_str(), j);
 }
 
-json_t *mmu::serialize()
+json_t *mmu::serialize() const
 {
 	json_t *j = json_object();
 
diff --git a/mmu.h b/mmu.h
index 3a80c0b..e78a5da 100644
--- a/mmu.h
+++ b/mmu.h
@@ -41,7 +41,7 @@ private:
 	uint16_t PIR { 0 };
 	uint16_t CSR { 0 };
 
-	void add_par_pdr(json_t *const target, const int run_mode, const bool is_d, const std::string & name);
+	void add_par_pdr(json_t *const target, const int run_mode, const bool is_d, const std::string & name) const;
 	void set_par_pdr(const json_t *const j_in, const int run_mode, const bool is_d, const std::string & name);
 
 public:
@@ -49,7 +49,7 @@ public:
 	virtual ~mmu();
 
 #if IS_POSIX
-	json_t *serialize();
+	json_t *serialize() const;
 	static mmu *deserialize(const json_t *const j);
 #endif