diff --git a/hardware/sam/cores/sam/Tone.cpp.xxx b/hardware/sam/cores/sam/Tone.cpp.disabled
similarity index 100%
rename from hardware/sam/cores/sam/Tone.cpp.xxx
rename to hardware/sam/cores/sam/Tone.cpp.disabled
diff --git a/hardware/sam/cores/sam/build_gcc/Makefile b/hardware/sam/cores/sam/build_gcc/Makefile
index 8dacf93d5..4943a9b93 100644
--- a/hardware/sam/cores/sam/build_gcc/Makefile
+++ b/hardware/sam/cores/sam/build_gcc/Makefile
@@ -1,6 +1,6 @@
 ifeq ("$(VARIANTS)", "")
-#VARIANTS = sam3s_ek sam3u_ek arduino_due
-VARIANTS = sam3u_ek
+VARIANTS = sam3s_ek sam3u_ek arduino_due
+#VARIANTS = sam3u_ek
 endif
 
 SUBMAKE_OPTIONS=--no-builtin-rules --no-builtin-variables
diff --git a/hardware/sam/cores/sam/build_gcc/libarduino_arduino_due.mk b/hardware/sam/cores/sam/build_gcc/libarduino_arduino_due.mk
index 215625adc..645f794f9 100644
--- a/hardware/sam/cores/sam/build_gcc/libarduino_arduino_due.mk
+++ b/hardware/sam/cores/sam/build_gcc/libarduino_arduino_due.mk
@@ -69,7 +69,7 @@ C_SRC=$(wildcard $(PROJECT_BASE_PATH)/*.c)
 C_OBJ_TEMP = $(patsubst %.c, %.o, $(notdir $(C_SRC)))
 
 # during development, remove some files
-C_OBJ_FILTER=wiring_analog.o wiring_pulse.o dlib_lowlevel_sam3.o
+C_OBJ_FILTER=dlib_lowlevel_sam3.o
 
 C_OBJ=$(filter-out $(C_OBJ_FILTER), $(C_OBJ_TEMP))
 
@@ -81,7 +81,7 @@ CPP_SRC=$(wildcard $(PROJECT_BASE_PATH)/*.cpp)
 CPP_OBJ_TEMP = $(patsubst %.cpp, %.o, $(notdir $(CPP_SRC)))
 
 # during development, remove some files
-CPP_OBJ_FILTER=Tone.o
+CPP_OBJ_FILTER=
 
 CPP_OBJ=$(filter-out $(CPP_OBJ_FILTER), $(CPP_OBJ_TEMP))
 
diff --git a/hardware/sam/cores/sam/build_gcc/libarduino_sam3s_ek.mk b/hardware/sam/cores/sam/build_gcc/libarduino_sam3s_ek.mk
index f48ee8891..c2547027c 100644
--- a/hardware/sam/cores/sam/build_gcc/libarduino_sam3s_ek.mk
+++ b/hardware/sam/cores/sam/build_gcc/libarduino_sam3s_ek.mk
@@ -69,7 +69,7 @@ C_SRC=$(wildcard $(PROJECT_BASE_PATH)/*.c)
 C_OBJ_TEMP = $(patsubst %.c, %.o, $(notdir $(C_SRC)))
 
 # during development, remove some files
-C_OBJ_FILTER=wiring_analog.o wiring_pulse.o dlib_lowlevel_sam3.o
+C_OBJ_FILTER=dlib_lowlevel_sam3.o
 
 C_OBJ=$(filter-out $(C_OBJ_FILTER), $(C_OBJ_TEMP))
 
@@ -81,7 +81,7 @@ CPP_SRC=$(wildcard $(PROJECT_BASE_PATH)/*.cpp)
 CPP_OBJ_TEMP = $(patsubst %.cpp, %.o, $(notdir $(CPP_SRC)))
 
 # during development, remove some files
-CPP_OBJ_FILTER=Tone.o
+CPP_OBJ_FILTER=
 
 CPP_OBJ=$(filter-out $(CPP_OBJ_FILTER), $(CPP_OBJ_TEMP))
 
diff --git a/hardware/sam/cores/sam/build_gcc/libarduino_sam3u_ek.mk b/hardware/sam/cores/sam/build_gcc/libarduino_sam3u_ek.mk
index 4ba65c7b7..46c101a35 100644
--- a/hardware/sam/cores/sam/build_gcc/libarduino_sam3u_ek.mk
+++ b/hardware/sam/cores/sam/build_gcc/libarduino_sam3u_ek.mk
@@ -69,7 +69,7 @@ C_SRC=$(wildcard $(PROJECT_BASE_PATH)/*.c)
 C_OBJ_TEMP = $(patsubst %.c, %.o, $(notdir $(C_SRC)))
 
 # during development, remove some files
-C_OBJ_FILTER=wiring_analog.o wiring_pulse.o dlib_lowlevel_sam3.o
+C_OBJ_FILTER=dlib_lowlevel_sam3.o
 
 C_OBJ=$(filter-out $(C_OBJ_FILTER), $(C_OBJ_TEMP))
 
@@ -81,7 +81,7 @@ CPP_SRC=$(wildcard $(PROJECT_BASE_PATH)/*.cpp)
 CPP_OBJ_TEMP = $(patsubst %.cpp, %.o, $(notdir $(CPP_SRC)))
 
 # during development, remove some files
-CPP_OBJ_FILTER=Tone.o
+CPP_OBJ_FILTER=
 
 CPP_OBJ=$(filter-out $(CPP_OBJ_FILTER), $(CPP_OBJ_TEMP))
 
diff --git a/hardware/sam/cores/sam/cortex_handlers.cpp b/hardware/sam/cores/sam/cortex_handlers.c
similarity index 100%
rename from hardware/sam/cores/sam/cortex_handlers.cpp
rename to hardware/sam/cores/sam/cortex_handlers.c
diff --git a/hardware/sam/cores/sam/validation/build_gcc/test.mk b/hardware/sam/cores/sam/validation/build_gcc/test.mk
index 8a1ecc334..829acb209 100644
--- a/hardware/sam/cores/sam/validation/build_gcc/test.mk
+++ b/hardware/sam/cores/sam/validation/build_gcc/test.mk
@@ -4,8 +4,8 @@
 # putting default variant
 ifeq ("$(VARIANT)", "")
 #VARIANT=sam3s_ek
-VARIANT=sam3u_ek
-#VARIANT=arduino_due
+#VARIANT=sam3u_ek
+VARIANT=arduino_due
 endif
 
 ifeq ("$(VARIANT)", "sam3s_ek")
diff --git a/hardware/sam/cores/sam/validation/test.cpp b/hardware/sam/cores/sam/validation/test.cpp
index 9b5d5b495..703b273c6 100644
--- a/hardware/sam/cores/sam/validation/test.cpp
+++ b/hardware/sam/cores/sam/validation/test.cpp
@@ -18,7 +18,7 @@ void setup( void )
   Serial.begin( 115200 ) ;
 }
 
-void led_step1( void )
+static void led_step1( void )
 {
 #if defined sam3s_ek
   digitalWrite( PIN_LED, HIGH ) ;  // set the LED on
@@ -36,7 +36,7 @@ void led_step1( void )
 #endif /* arduino_due */
 }
 
-void led_step2( void )
+static void led_step2( void )
 {
 #if defined sam3s_ek
   digitalWrite( PIN_LED, LOW ) ;   // set the LED off
@@ -61,8 +61,7 @@ void loop( void )
   led_step2() ;
   delay( 1000 ) ;              // wait for a second
 
-  Serial.write( '-' ) ;   // send an initial char
-  Serial.println( "test1\n" ) ;   // send an initial string
-//  delay( 1000 ) ;               // wait for a second
-//  Serial.println( "test2" ) ;   // send an initial string
+  Serial.write( '-' ) ;   // send a char
+  Serial.println( "test1\n" ) ;   // send a string
+  Serial.println( "test2" ) ;   // send another string
 }
diff --git a/hardware/sam/cores/sam/wiring_analog.c.xxx b/hardware/sam/cores/sam/wiring_analog.c.disabled
similarity index 100%
rename from hardware/sam/cores/sam/wiring_analog.c.xxx
rename to hardware/sam/cores/sam/wiring_analog.c.disabled
diff --git a/hardware/sam/cores/sam/wiring_pulse.c.xxx b/hardware/sam/cores/sam/wiring_pulse.c.disabled
similarity index 100%
rename from hardware/sam/cores/sam/wiring_pulse.c.xxx
rename to hardware/sam/cores/sam/wiring_pulse.c.disabled
diff --git a/hardware/sam/system/libsam/source/adc.c b/hardware/sam/system/libsam/source/adc.c.disabled
similarity index 100%
rename from hardware/sam/system/libsam/source/adc.c
rename to hardware/sam/system/libsam/source/adc.c.disabled
diff --git a/hardware/sam/variants/arduino_due/1661fa.pdf b/hardware/sam/variants/arduino_due/1661fa.pdf
new file mode 100644
index 000000000..bda8df4cb
Binary files /dev/null and b/hardware/sam/variants/arduino_due/1661fa.pdf differ
diff --git a/hardware/sam/variants/arduino_due/variant.h b/hardware/sam/variants/arduino_due/variant.h
index 50504ef8b..f6d033c7b 100644
--- a/hardware/sam/variants/arduino_due/variant.h
+++ b/hardware/sam/variants/arduino_due/variant.h
@@ -10,8 +10,8 @@
  *----------------------------------------------------------------------------*/
 
 #include "Arduino.h"
-#include "common/UART.h"
-#include "common/USART.h"
+#include "UART.h"
+#include "USART.h"
 
 /**
  * Libc porting layers
diff --git a/hardware/sam/variants/sam3s_ek/variant.h b/hardware/sam/variants/sam3s_ek/variant.h
index 13552492e..0f706e679 100644
--- a/hardware/sam/variants/sam3s_ek/variant.h
+++ b/hardware/sam/variants/sam3s_ek/variant.h
@@ -10,8 +10,8 @@
  *----------------------------------------------------------------------------*/
 
 #include "Arduino.h"
-#include "common/UART.h"
-#include "common/USART.h"
+#include "UART.h"
+#include "USART.h"
 
 /**
  * Libc porting layers
diff --git a/hardware/sam/variants/sam3u_ek/build_gcc/libvariant_sam3u_ek.mk b/hardware/sam/variants/sam3u_ek/build_gcc/libvariant_sam3u_ek.mk
index eb1b64ec9..13f744f93 100644
--- a/hardware/sam/variants/sam3u_ek/build_gcc/libvariant_sam3u_ek.mk
+++ b/hardware/sam/variants/sam3u_ek/build_gcc/libvariant_sam3u_ek.mk
@@ -20,15 +20,17 @@ CMSIS_PATH = $(SYSTEM_PATH)/CMSIS/Include
 ARDUINO_PATH = ../../../cores/sam
 VARIANT_BASE_PATH = ../../../variants
 VARIANT_PATH = ../../../variants/$(VARIANT)
-VARIANT_COMMON_PATH = ../../common
+#VARIANT_COMMON_PATH = ../../common
 
 #-------------------------------------------------------------------------------
 # Files
 #-------------------------------------------------------------------------------
 
-vpath %.h $(PROJECT_BASE_PATH) $(SYSTEM_PATH) $(VARIANT_PATH) $(VARIANT_COMMON_PATH)
+vpath %.h $(PROJECT_BASE_PATH) $(SYSTEM_PATH) $(VARIANT_PATH) 
+#$(VARIANT_COMMON_PATH)
 #vpath %.c $(PROJECT_BASE_PATH) $(VARIANT_PATH)
-vpath %.cpp $(PROJECT_BASE_PATH) $(PROJECT_BASE_PATH) $(VARIANT_COMMON_PATH)
+vpath %.cpp $(PROJECT_BASE_PATH) $(PROJECT_BASE_PATH) 
+#$(VARIANT_COMMON_PATH)
 
 VPATH+=$(PROJECT_BASE_PATH)
 
@@ -74,7 +76,7 @@ C_SRC=$(wildcard $(PROJECT_BASE_PATH)/*.c)
 C_OBJ_TEMP = $(patsubst %.c, %.o, $(notdir $(C_SRC)))
 
 # during development, remove some files
-C_OBJ_FILTER=wiring_analog.o wiring_pulse.o
+C_OBJ_FILTER=
 
 C_OBJ=$(filter-out $(C_OBJ_FILTER), $(C_OBJ_TEMP))
 
@@ -82,12 +84,12 @@ C_OBJ=$(filter-out $(C_OBJ_FILTER), $(C_OBJ_TEMP))
 # CPP source files and objects
 #-------------------------------------------------------------------------------
 CPP_SRC=$(wildcard $(PROJECT_BASE_PATH)/*.cpp)
-CPP_SRC+=$(wildcard $(VARIANT_COMMON_PATH)/*.cpp)
+#CPP_SRC+=$(wildcard $(VARIANT_COMMON_PATH)/*.cpp)
 
 CPP_OBJ_TEMP = $(patsubst %.cpp, %.o, $(notdir $(CPP_SRC)))
 
 # during development, remove some files
-CPP_OBJ_FILTER=Tone.o
+CPP_OBJ_FILTER=
 
 CPP_OBJ=$(filter-out $(CPP_OBJ_FILTER), $(CPP_OBJ_TEMP))
 
diff --git a/hardware/sam/variants/sam3u_ek/variant.h b/hardware/sam/variants/sam3u_ek/variant.h
index d890bb450..12e93f4f2 100644
--- a/hardware/sam/variants/sam3u_ek/variant.h
+++ b/hardware/sam/variants/sam3u_ek/variant.h
@@ -10,8 +10,8 @@
  *----------------------------------------------------------------------------*/
 
 #include "Arduino.h"
-#include "common/UART.h"
-#include "common/USART.h"
+#include "UART.h"
+#include "USART.h"
 
 /**
  * Libc porting layers