diff --git a/bacnet-stack/ai.c b/bacnet-stack/ai.c
index fee8627f..7355a2a4 100644
--- a/bacnet-stack/ai.c
+++ b/bacnet-stack/ai.c
@@ -131,13 +131,18 @@ void testAnalogInput(Test * pTest)
   BACNET_OBJECT_TYPE decoded_type = OBJECT_ANALOG_OUTPUT;
   uint32_t decoded_instance = 0;
   uint32_t instance = 123;
+  BACNET_ERROR_CLASS error_class;
+  BACNET_ERROR_CODE error_code;
 
-  
+
+  // FIXME: we should do a lot more testing here...
   len = Analog_Input_Encode_Property_APDU(
     &apdu[0],
     instance,
     PROP_OBJECT_IDENTIFIER,
-    BACNET_ARRAY_ALL);
+    BACNET_ARRAY_ALL,
+    &error_class,
+    &error_code);
   ct_test(pTest, len != 0);
   len = decode_tag_number_and_value(&apdu[0], &tag_number, &len_value);
   ct_test(pTest, tag_number == BACNET_APPLICATION_TAG_OBJECT_ID);
diff --git a/bacnet-stack/apdu.c b/bacnet-stack/apdu.c
index 70fecaab..9e7bf749 100644
--- a/bacnet-stack/apdu.c
+++ b/bacnet-stack/apdu.c
@@ -42,25 +42,6 @@
 #include "tsm.h"
 #include "iam.h"
 
-#ifdef TEST
-void tsm_free_invoke_id(uint8_t invokeID)
-{
-  // dummy stub for testing
-  (void)invokeID;
-}
-
-void iam_handler(
-  uint8_t *service_request,
-  uint16_t service_len,
-  BACNET_ADDRESS *src)
-{
-  // dummy stub for testing
-  (void)service_request;
-  (void)service_len;
-  (void)src;
-}
-#endif
-
 // Confirmed Function Handlers
 // If they are not set, they are handled by a reject message
 static confirmed_function 
@@ -360,3 +341,4 @@ void apdu_handler(
   }
   return;
 }
+
diff --git a/bacnet-stack/datalink.c b/bacnet-stack/datalink.c
index 8de7edeb..ed093c30 100644
--- a/bacnet-stack/datalink.c
+++ b/bacnet-stack/datalink.c
@@ -40,6 +40,7 @@
 // addition of passing a network number or datalink number
 // as part of the calls.
 
+/* returns number of bytes sent on success, negative on failure */
 int datalink_send_pdu(
   BACNET_ADDRESS *dest,  // destination address
   uint8_t *pdu, // any data to be sent - may be null
diff --git a/bacnet-stack/datalink.h b/bacnet-stack/datalink.h
index d2cc67e4..54665fcd 100644
--- a/bacnet-stack/datalink.h
+++ b/bacnet-stack/datalink.h
@@ -51,7 +51,7 @@
 #include "bip.h"
 #endif
 
-
+/* returns number of bytes sent on success, negative on failure */
 int datalink_send_pdu(
   BACNET_ADDRESS *dest,  // destination address
   uint8_t *pdu, // any data to be sent - may be null
diff --git a/bacnet-stack/device.c b/bacnet-stack/device.c
index ce00e83e..e5b10ff7 100644
--- a/bacnet-stack/device.c
+++ b/bacnet-stack/device.c
@@ -538,6 +538,39 @@ void testDevice(Test * pTest)
 }
 
 #ifdef TEST_DEVICE
+// stubs to dependencies to keep unit test simple
+unsigned Analog_Input_Count(void)
+{
+  return 0;
+}
+
+uint32_t Analog_Input_Index_To_Instance(unsigned index)
+{
+  return index;
+}
+
+unsigned Analog_Output_Count(void)
+{
+  return 0;
+}
+
+uint32_t Analog_Output_Index_To_Instance(unsigned index)
+{
+  return index;
+}
+
+uint32_t bacfile_count(void)
+{
+  return 0;
+}
+
+uint32_t bacfile_index_to_instance(unsigned find_index)
+{
+  return find_index;
+}
+
+bool I_Am_Request = false;
+
 int main(void)
 {
     Test *pTest;
diff --git a/bacnet-stack/ethernet.h b/bacnet-stack/ethernet.h
index 8f7c44bb..3fdc3b29 100644
--- a/bacnet-stack/ethernet.h
+++ b/bacnet-stack/ethernet.h
@@ -48,7 +48,7 @@ void ethernet_cleanup(void);
 bool ethernet_init(char *interface_name);
 
 /* function to send a packet out the 802.2 socket */
-/* returns 0 on success, non-zero on failure */
+/* returns number of bytes sent on success, negative on failure */
 int ethernet_send(
   BACNET_ADDRESS *dest,  // destination address
   BACNET_ADDRESS *src,  // source address
@@ -56,7 +56,7 @@ int ethernet_send(
   unsigned pdu_len); // number of bytes of data
 
 /* function to send a packet out the 802.2 socket */
-/* returns zero on success, non-zero on failure */
+/* returns number of bytes sent on success, negative on failure */
 int ethernet_send_pdu(
   BACNET_ADDRESS *dest,  // destination address
   uint8_t *pdu, // any data to be sent - may be null
diff --git a/bacnet-stack/iam.c b/bacnet-stack/iam.c
index 77bc3307..d0b61fb1 100755
--- a/bacnet-stack/iam.c
+++ b/bacnet-stack/iam.c
@@ -266,6 +266,52 @@ void testIAm(Test * pTest)
 }
 
 #ifdef TEST_IAM
+// Dummy stubs to eliminate depencies
+void datalink_get_broadcast_address(
+  BACNET_ADDRESS *dest) // destination address
+{
+  (void)dest;
+}
+
+int datalink_send_pdu(
+  BACNET_ADDRESS *dest,  // destination address
+  uint8_t *pdu, // any data to be sent - may be null
+  unsigned pdu_len) // number of bytes of data
+{
+  (void)dest;
+  (void)pdu;
+
+  return pdu_len;
+}
+
+uint16_t Device_Vendor_Identifier(void)
+{
+  return 0;
+}
+
+uint32_t Device_Object_Instance_Number(void)
+{
+  return 0;
+}
+
+void address_add_binding(
+  uint32_t device_id,
+  unsigned max_apdu,
+  BACNET_ADDRESS *src)
+{
+  (void)device_id;
+  (void)max_apdu;
+  (void)src;
+}
+
+// dummy for apdu dependency
+void tsm_free_invoke_id(uint8_t invokeID)
+{
+  // dummy stub for testing
+  (void)invokeID;
+}
+
+
 int main(void)
 {
     Test *pTest;
diff --git a/bacnet-stack/iam.mak b/bacnet-stack/iam.mak
index 828823d1..b560b00c 100755
--- a/bacnet-stack/iam.mak
+++ b/bacnet-stack/iam.mak
@@ -8,6 +8,8 @@ CFLAGS  = -Wall -I. -Itest -DTEST -DTEST_IAM -g
 
 SRCS = bacdcode.c \
        bigend.c \
+       npdu.c \
+       apdu.c \
        iam.c \
        test/ctest.c
 
diff --git a/bacnet-stack/mstp.c b/bacnet-stack/mstp.c
index 94956818..01908576 100644
--- a/bacnet-stack/mstp.c
+++ b/bacnet-stack/mstp.c
@@ -1114,7 +1114,7 @@ void MSTP_Master_Node_FSM(volatile struct mstp_port_struct_t *mstp_port)
             FRAME_TYPE_TEST_RESPONSE,
             mstp_port->SourceAddress,
             mstp_port->This_Station,
-            mstp_port->InputBuffer,
+            (uint8_t *)&mstp_port->InputBuffer[0],
             mstp_port->Index);
         }
         mstp_port->master_state = MSTP_MASTER_STATE_IDLE;
@@ -1210,7 +1210,7 @@ void RS485_Send_Frame(
 }
 
 #define RING_BUFFER_DATA_SIZE 1
-#define RING_BUFFER_SIZE INPUT_BUFFER_SIZE
+#define RING_BUFFER_SIZE MAX_MPDU
 static RING_BUFFER Test_Buffer;
 static uint8_t Test_Buffer_Data[RING_BUFFER_DATA_SIZE * RING_BUFFER_SIZE];
 static void Load_Input_Buffer(uint8_t *buffer,size_t len)
@@ -1270,8 +1270,8 @@ void testReceiveNodeFSM(Test* pTest)
   uint8_t FrameType = 0; // type of packet that was sent
   unsigned len; // used for the size of the message packet
   size_t i; // used to loop through the message bytes
-  uint8_t buffer[INPUT_BUFFER_SIZE] = {0};
-  uint8_t data[INPUT_BUFFER_SIZE - 8 /*header*/ - 2 /*CRC*/] = {0};
+  uint8_t buffer[MAX_MPDU] = {0};
+  uint8_t data[MAX_MPDU - 8 /*header*/ - 2 /*CRC*/] = {0};
 
   MSTP_Init(&mstp_port,my_mac);
 
diff --git a/bacnet-stack/npdu.c b/bacnet-stack/npdu.c
index d8f4eeef..6bab0efd 100644
--- a/bacnet-stack/npdu.c
+++ b/bacnet-stack/npdu.c
@@ -484,6 +484,22 @@ void testNPDU1(Test * pTest)
 }
 
 #ifdef TEST_NPDU
+// dummy stub for testing
+void tsm_free_invoke_id(uint8_t invokeID)
+{
+  (void)invokeID;
+}
+
+void iam_handler(
+  uint8_t *service_request,
+  uint16_t service_len,
+  BACNET_ADDRESS *src)
+{
+  (void)service_request;
+  (void)service_len;
+  (void)src;
+}
+
 int main(void)
 {
     Test *pTest;