diff --git a/src/Makefile b/src/Makefile
index 1f1d6ca..cfad722 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -5,7 +5,7 @@ include ../make/mips_app.mk
 		
 PROG-ml402 = $(addprefix $(BUILD_DIR)/, hello.elf testbench.elf test_irq.elf dhry.elf queens.elf stanford.elf paranoia.elf rmd160_test.elf Bessel.elf whet.elf phrasen.elf dttl.elf richards_benchmark.elf test_exception.elf life.elf r3.elf gunzip.elf basic_math.elf jman_patches.elf jman_patchmeshes.elf jman_polys.elf test_hpi.elf test_vga.elf test_fft.elf)
 PROG-denano = $(addprefix $(BUILD_DIR)/, hello.elf dhry.elf queens.elf stanford.elf paranoia.elf rmd160_test.elf Bessel.elf whet.elf phrasen.elf dttl.elf richards_benchmark.elf test_exception.elf testbench_denano.elf)
-PROG-sim = $(addprefix $(BUILD_DIR)/, hello.elf)
+PROG-sim = $(addprefix $(BUILD_DIR)/, hello.elf test_exception_sim.elf)
 		  
 all: $(PROG-$(BOARD))
 
@@ -299,7 +299,7 @@ $(BUILD_DIR)/lwl.elf: $(BUILD_DIR) lwl.c
 	$(OBJCOPY) -O ihex -I binary $@.flash.bin $@.hex
 
 $(BUILD_DIR)/ucb.elf: $(BUILD_DIR) ucb.c
-	$(CC) $(CFLAGS) -O2 -o $@ ucb.c -lsys_sim >$@.map
+	$(CC) $(CFLAGS) -O2 -o $@ ucb.c $(LIBS) >$@.map
 	$(OBJDUMP) -d $@ > $@.dis
 	$(OBJCOPY) $@ -O binary $@.bin
 	$(OBJCOPY) -O srec $@ $@.srec
@@ -308,7 +308,7 @@ $(BUILD_DIR)/ucb.elf: $(BUILD_DIR) ucb.c
 	$(OBJCOPY) -O ihex -I binary $@.flash.bin $@.hex
 
 $(BUILD_DIR)/test_timer.elf: $(BUILD_DIR) test_timer.c
-	$(CC) $(CFLAGS) -O2 -o $@ test_timer.c -lsys_sim >$@.map
+	$(CC) $(CFLAGS) -O2 -o $@ test_timer.c $(LIBS) >$@.map
 	$(OBJDUMP) -d $@ > $@.dis
 	$(OBJCOPY) $@ -O binary $@.bin
 	$(OBJCOPY) -O srec $@ $@.srec
@@ -317,7 +317,7 @@ $(BUILD_DIR)/test_timer.elf: $(BUILD_DIR) test_timer.c
 	$(OBJCOPY) -O ihex -I binary $@.flash.bin $@.hex
 
 $(BUILD_DIR)/test_exception_sim.elf: $(BUILD_DIR) test_exception_sim.c
-	$(CC) $(CFLAGS) -O2 -o $@ test_exception_sim.c -lsys_sim >$@.map
+	$(CC) $(CFLAGS) -o $@ test_exception_sim.c $(LIBS) >$@.map
 	$(OBJDUMP) -d $@ > $@.dis
 	$(OBJCOPY) $@ -O binary $@.bin
 	$(OBJCOPY) -O srec $@ $@.srec
@@ -326,7 +326,7 @@ $(BUILD_DIR)/test_exception_sim.elf: $(BUILD_DIR) test_exception_sim.c
 	$(OBJCOPY) -O ihex -I binary $@.flash.bin $@.hex
 
 $(BUILD_DIR)/test_tlb_sim.elf: $(BUILD_DIR) test_tlb_sim.c
-	$(CC) $(CFLAGS) -O2 -o $@ test_tlb_sim.c -lsys_sim >$@.map
+	$(CC) $(CFLAGS) -O2 -o $@ test_tlb_sim.c $(LIBS) >$@.map
 	$(OBJDUMP) -d $@ > $@.dis
 	$(OBJCOPY) $@ -O binary $@.bin
 	$(OBJCOPY) -O srec $@ $@.srec
@@ -335,7 +335,7 @@ $(BUILD_DIR)/test_tlb_sim.elf: $(BUILD_DIR) test_tlb_sim.c
 	$(OBJCOPY) -O ihex -I binary $@.flash.bin $@.hex
 
 $(BUILD_DIR)/test_dcache_sim.elf: $(BUILD_DIR) test_dcache.c
-	$(CC) $(CFLAGS) -O0 -o $@ test_dcache.c -lsys_sim >$@.map
+	$(CC) $(CFLAGS) -O0 -o $@ test_dcache.c $(LIBS) >$@.map
 	$(OBJDUMP) -d $@ > $@.dis
 	$(OBJCOPY) $@ -O binary $@.bin
 	$(OBJCOPY) -O srec $@ $@.srec
diff --git a/src/libsys/irq.h b/src/libsys/irq.h
index d6a1d2e..2ddba26 100644
--- a/src/libsys/irq.h
+++ b/src/libsys/irq.h
@@ -14,5 +14,7 @@ void interrupt_enable(int irq_num);
 void interrupt_disable(int irq_num);
 void interrupt_global_enable();
 void interrupt_global_disable();
+void interrupt_set(int irq_num);
+void interrupt_clr(int irq_num);
 
 #endif // IRQ_H
diff --git a/src/test_exception_sim.c b/src/test_exception_sim.c
index c065ec8..57a2dc7 100644
--- a/src/test_exception_sim.c
+++ b/src/test_exception_sim.c
@@ -1,9 +1,10 @@
 #include <stdlib.h>
 #include <stdio.h>
-#include "libsys.h"
+#include <libsys.h>
+#include <irq.h>
 #include "xcpt.h"
-
 #define MAX_NUM_EXCEPTIONS	10
+
 void *g_fp_badsubs[MAX_NUM_EXCEPTIONS];
 
 void _exc_break(void)
@@ -17,7 +18,7 @@ void _exc_break(void)
 	);
 }
 
-void _exc_syscall(UINT32 code, UINT32 arg)
+void _exc_syscall(uint32_t code, uint32_t arg)
 {
 	__asm
 	(
@@ -212,13 +213,13 @@ void _exc_dbe(void)
 
 }
 
-void handler0(void)
+void handler0(struct xcptcontext *xcp)
 {
 	sputs("Interrupt 0\n");
 	interrupt_clr(0);
 }
 
-void handler1(void)
+void handler1(struct xcptcontext *xcp)
 {
 	sputs("Interrupt 1\n");
 	interrupt_clr(1);
@@ -234,8 +235,8 @@ int xcp_handler(struct xcptcontext * xcp)
 
 	if (xcpt_get_type(xcp) == EXC_INT)
 	{
-		interrupt_clr(0);
-		interrupt_clr(1);
+		interrupt_disable(0);
+		interrupt_disable(1);
 	}
 	else
 	{
@@ -274,9 +275,9 @@ int main(void)
 	interrupt_set(1);
 
 	sputs(" 4 : Syscall\n");
-	_exc_syscall(4, (UINT32)((char*)"Hallo Syscall ("));
+	_exc_syscall(4, (uint32_t)((char*)"Hallo Syscall ("));
 	_exc_syscall(1, 12345678);
-	_exc_syscall(4, (UINT32)((char*)")\n"));
+	_exc_syscall(4, (uint32_t)((char*)")\n"));
 
 	sputs(" 5 : Breakpoint\n");
 	_exc_break();