diff --git a/src/debug.c b/src/debug.c
index 38f0b1f..90cdfdc 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -3,8 +3,60 @@
 #include <utlist.h>
 
 #include "rk65c02.h"
+#include "instruction.h"
 #include "debug.h"
 
+void
+debug_trace_set(rk65c02emu_t *e, bool state)
+{
+	e->trace = state;
+}
+
+void
+debug_trace_print_all(rk65c02emu_t *e)
+{
+	trace_t *tr;
+	instruction_t i;
+
+	if (e->trace_head == NULL)
+		return;
+
+	DL_FOREACH(e->trace_head, tr) {
+		i.opcode = tr->opcode;
+		i.op1 = tr->op1;
+		i.op2 = tr->op2;
+
+		printf("TRACE %X:\t", tr->address);
+		instruction_print(&i);
+		printf("\t");
+		rk65c02_dump_regs(tr->regs);
+	}
+
+}
+
+void
+debug_trace_savestate(rk65c02emu_t *e, uint16_t address, instrdef_t *id,
+    instruction_t *i)
+{
+	trace_t *tr;
+
+	tr = (trace_t *) malloc(sizeof(trace_t));
+	if (tr == NULL) {
+		fprintf(stderr, "Error allocating trace structure.\n");
+		return;
+	}
+
+	tr->address = address;
+
+	tr->opcode = i->opcode;
+	tr->op1 = i->op1;
+	tr->op2 = i->op2; 
+
+	tr->regs = e->regs;
+
+	DL_APPEND((e->trace_head), tr);
+}
+
 bool
 debug_breakpoint_remove(rk65c02emu_t *e, uint16_t address)
 {
diff --git a/src/debug.h b/src/debug.h
index ec6346d..3a0b51f 100644
--- a/src/debug.h
+++ b/src/debug.h
@@ -5,10 +5,15 @@
 #include <stdbool.h>
 
 #include "rk65c02.h" 
+#include "instruction.h"
 
 bool debug_PC_is_breakpoint(rk65c02emu_t *);
 bool debug_breakpoint_add(rk65c02emu_t *, uint16_t);
 bool debug_breakpoint_remove(rk65c02emu_t *, uint16_t);
 
+void debug_trace_set(rk65c02emu_t *, bool);
+void debug_trace_savestate(rk65c02emu_t *, uint16_t, instrdef_t *, instruction_t *);
+void debug_trace_print_all(rk65c02emu_t *);
+
 #endif /* _DEBUG_H_ */
 
diff --git a/src/rk65c02.c b/src/rk65c02.c
index 2529c78..4960e43 100644
--- a/src/rk65c02.c
+++ b/src/rk65c02.c
@@ -31,6 +31,7 @@ rk65c02_init(bus_t *b)
 	e.irq = false;
 
 	e.bps_head = NULL;
+	e.trace_head = NULL;
 
 	return e;
 }
@@ -88,6 +89,9 @@ rk65c02_exec(rk65c02emu_t *e)
 {
 	instruction_t i;
 	instrdef_t id;
+	uint16_t tpc;	/* saved PC for tracing */
+
+	tpc = e->regs.PC;
 
 	if (e->irq && (!(e->regs.P & P_IRQ_DISABLE)))
 		rk65c02_irq(e);
@@ -107,6 +111,7 @@ rk65c02_exec(rk65c02emu_t *e)
 
 	if (id.emul != NULL) {
 		id.emul(e, &id, &i);
+
 		if (!instruction_modify_pc(&id)) 
 			program_counter_increment(e, &id);
 	} else {
@@ -115,6 +120,10 @@ rk65c02_exec(rk65c02emu_t *e)
 		e->state = STOPPED;
 		e->stopreason = EMUERROR;
 	}
+
+	if (e->trace)
+		debug_trace_savestate(e, tpc, &id, &i);
+
 }
 
 /*
@@ -173,47 +182,47 @@ rk65c02_dump_stack(rk65c02emu_t *e, uint8_t n)
 }
 
 void
-rk65c02_dump_regs(rk65c02emu_t *e)
+rk65c02_dump_regs(reg_state_t regs)
 {
 	printf("A: %X X: %X Y: %X PC: %X SP: %X P: ", 
-	    e->regs.A, e->regs.X, e->regs.Y, e->regs.PC, e->regs.SP);
+	    regs.A, regs.X, regs.Y, regs.PC, regs.SP);
 
-	if (e->regs.P & P_NEGATIVE)
+	if (regs.P & P_NEGATIVE)
 		printf("N");
 	else
 		printf("-");
 
-	if (e->regs.P & P_SIGN_OVERFLOW)
+	if (regs.P & P_SIGN_OVERFLOW)
 		printf("V");
 	else
 		printf("-");
 
-	if (e->regs.P & P_UNDEFINED)
+	if (regs.P & P_UNDEFINED)
 		printf("1");
 	else
 		printf("-");
 
-	if (e->regs.P & P_BREAK)
+	if (regs.P & P_BREAK)
 		printf("B");
 	else
 		printf("-");
 
-	if (e->regs.P & P_DECIMAL)
+	if (regs.P & P_DECIMAL)
 		printf("D");
 	else
 		printf("-");
 
-	if (e->regs.P & P_IRQ_DISABLE)
+	if (regs.P & P_IRQ_DISABLE)
 		printf("I");
 	else
 		printf("-");
 
-	if (e->regs.P & P_ZERO)
+	if (regs.P & P_ZERO)
 		printf("Z");
 	else
 		printf("-");
 
-	if (e->regs.P & P_CARRY)
+	if (regs.P & P_CARRY)
 		printf("C");
 	else
 		printf("-");
diff --git a/src/rk65c02.h b/src/rk65c02.h
index 497ece4..d5b4479 100644
--- a/src/rk65c02.h
+++ b/src/rk65c02.h
@@ -54,14 +54,24 @@ typedef struct breakpoint_t {
 	struct breakpoint_t *next;
 } breakpoint_t;
 
+typedef struct trace_t {
+	uint16_t address;
+	uint8_t opcode, op1, op2;
+	reg_state_t regs;
+	struct trace_t *prev,*next;
+} trace_t;
+
 struct rk65c02emu {
 	emu_state_t state;
 	bus_t *bus;
 	reg_state_t regs;
 	emu_stop_reason_t stopreason;
-	bool irq;	/* interrupt request line state, true is asserted */
+	bool irq;		/* interrupt request line state, true is asserted */
 
 	breakpoint_t *bps_head;	/* pointer to linked list with breakpoints  */
+
+	bool trace;		/* tracing mode enable/disable */
+	trace_t *trace_head;	/* pointer to linked list with trace log */
 };
 
 typedef struct rk65c02emu rk65c02emu_t;
@@ -69,7 +79,7 @@ typedef struct rk65c02emu rk65c02emu_t;
 rk65c02emu_t rk65c02_init(bus_t *);
 void rk65c02_start(rk65c02emu_t *);
 void rk65c02_step(rk65c02emu_t *, uint16_t);
-void rk65c02_dump_regs(rk65c02emu_t *);
+void rk65c02_dump_regs(reg_state_t regs);
 void rk65c02_dump_stack(rk65c02emu_t *, uint8_t);
 void rk65c02_irq(rk65c02emu_t *e);