diff --git a/test/Kyuafile b/test/Kyuafile
index 4d88baa..a3614c1 100644
--- a/test/Kyuafile
+++ b/test/Kyuafile
@@ -5,6 +5,7 @@ test_suite('rk65c02-tests')
 atf_test_program{name='test_assemble'}
 atf_test_program{name='test_bus'}
 atf_test_program{name='test_debug'}
+--atf_test_program{name='test_device_serial'}
 atf_test_program{name='test_emulation'}
 atf_test_program{name='test_interrupt'}
 atf_test_program{name='test_stepping'}
diff --git a/test/Makefile b/test/Makefile
index c7e9d27..80845f3 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -5,7 +5,7 @@ VASM=vasm6502_std
 VASMFLAGS=-Fbin -c02
 UTILS=utils.o
 
-TESTS=test_bus test_emulation test_stepping test_assemble test_interrupt test_debug
+TESTS=test_bus test_emulation test_stepping test_assemble test_interrupt test_debug test_device_serial
 TESTROMS:=$(addsuffix .rom,$(basename $(wildcard *.s)))
 
 all : $(TESTS) $(TESTROMS)
@@ -28,6 +28,9 @@ test_interrupt: test_interrupt.o $(UTILS) $(RK6502LIB)
 test_debug: test_debug.o $(UTILS) $(RK6502LIB)
 	$(CC) -o $@ $(LDFLAGS) $< $(UTILS) $(RK6502LIB)
 
+test_device_serial: test_device_serial.o $(UTILS) $(RK6502LIB)
+	$(CC) -o $@ $(LDFLAGS) $< $(UTILS) $(RK6502LIB)
+
 %.rom : %.s
 	$(VASM) $(VASMFLAGS) -o $@ $< 
 
diff --git a/test/test_device_serial.c b/test/test_device_serial.c
new file mode 100644
index 0000000..aa6eaa8
--- /dev/null
+++ b/test/test_device_serial.c
@@ -0,0 +1,66 @@
+#include <atf-c.h>
+
+#include <stdio.h>
+#include <string.h>
+
+#include <utlist.h>
+
+#include "rk65c02.h"
+#include "bus.h"
+#include "utils.h"
+#include "device_serial.h"
+
+ATF_TC_WITHOUT_HEAD(device_serial_init);
+ATF_TC_BODY(device_serial_init, tc)
+{
+	bus_t b;
+	device_mapping_t *dm;
+	device_t *d, *d_ser;
+
+	b = bus_init_with_default_devs();
+
+	bus_device_add(&b, device_serial_init(), 0xE000);
+
+	bus_device_dump(&b);
+
+	LL_FOREACH(b.dm_head, dm) {
+		d = dm->dev;
+
+		if (dm->addr == 0xE000)
+			d_ser = d;
+	}
+
+	ATF_CHECK(strcmp("Serial", d_ser->name) == 0);
+
+	bus_finish(&b);
+}
+
+ATF_TC_WITHOUT_HEAD(device_serial_write1);
+ATF_TC_BODY(device_serial_write1, tc)
+{
+	bus_t b;
+	rk65c02emu_t e;
+
+	b = bus_init_with_default_devs();
+
+	bus_device_add(&b, device_serial_init(), 0xE000);
+	bus_device_dump(&b);
+
+	e = rk65c02_init(&b);
+
+	ATF_REQUIRE(rom_start(&e, "test_device_serial_write1.rom", tc));
+
+	// start thread reading from txpipe
+
+	/* clean up serial etc. */
+	bus_finish(&b);
+}
+
+ATF_TP_ADD_TCS(tp)
+{
+	ATF_TP_ADD_TC(tp, device_serial_init);
+	ATF_TP_ADD_TC(tp, device_serial_write1);
+
+	return (atf_no_error());
+}
+
diff --git a/test/test_device_serial_write1.s b/test/test_device_serial_write1.s
new file mode 100644
index 0000000..799928d
--- /dev/null
+++ b/test/test_device_serial_write1.s
@@ -0,0 +1,6 @@
+start:  lda #0x61
+	sta 0xE000
+	lda #0x0A
+	sta 0xE000
+	stp
+