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 05c3b8c00..f48ee8891 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
+C_OBJ_FILTER=wiring_analog.o wiring_pulse.o dlib_lowlevel_sam3.o
 
 C_OBJ=$(filter-out $(C_OBJ_FILTER), $(C_OBJ_TEMP))
 
diff --git a/hardware/sam/system/libsam/build_gcc/sam3.mk b/hardware/sam/system/libsam/build_gcc/sam3.mk
index 81a2d90e1..51135bed0 100644
--- a/hardware/sam/system/libsam/build_gcc/sam3.mk
+++ b/hardware/sam/system/libsam/build_gcc/sam3.mk
@@ -121,10 +121,10 @@ $(CHIP): create_output $(OUTPUT_LIB)
 create_output:
 	@echo --- Preparing $(CHIP) files $(OUTPUT_PATH) $(OUTPUT_BIN)
 	@echo -------------------------
-#	@echo *$(C_SRC)
-#	@echo -------------------------
-#	@echo *$(C_OBJ)
-#	@echo -------------------------
+	@echo *$(C_SRC)
+	@echo -------------------------
+	@echo *$(C_OBJ)
+	@echo -------------------------
 #	@echo *$(addprefix $(OUTPUT_PATH)/, $(C_OBJ))
 #	@echo -------------------------
 #	@echo *$(A_SRC)
diff --git a/hardware/sam/system/libsam/cmsis/sam3s/source/templates/exceptions.c b/hardware/sam/system/libsam/cmsis/sam3s/source/templates/exceptions.c
index 5ed6a5892..ae895cc17 100644
--- a/hardware/sam/system/libsam/cmsis/sam3s/source/templates/exceptions.c
+++ b/hardware/sam/system/libsam/cmsis/sam3s/source/templates/exceptions.c
@@ -31,9 +31,9 @@ extern "C" {
 
 #ifdef __GNUC__
 /* Cortex-M3 core handlers */
-extern void Reset_Handler( void ) __attribute__ ((weak, alias ("Dummy_Handler"))) ;
+//extern void Reset_Handler( void ) __attribute__ ((weak, alias ("Dummy_Handler"))) ;
 extern void NMI_Handler( void ) __attribute__ ((weak, alias ("Dummy_Handler"))) ;
-extern void HardFault_Handler( void ) __attribute__ ((weak, alias ("Dummy_Handler"))) ;
+//extern void HardFault_Handler( void ) __attribute__ ((weak, alias ("Dummy_Handler"))) ;
 extern void MemManage_Handler( void ) __attribute__ ((weak, alias ("Dummy_Handler"))) ;
 extern void BusFault_Handler( void ) __attribute__ ((weak, alias ("Dummy_Handler"))) ;
 extern void UsageFault_Handler( void ) __attribute__ ((weak, alias ("Dummy_Handler"))) ;
diff --git a/hardware/sam/system/libsam/cmsis/sam3s/source/templates/gcc/startup_sam3s.c b/hardware/sam/system/libsam/cmsis/sam3s/source/templates/gcc/startup_sam3s.c
index 7cd2a981c..671757e0d 100644
--- a/hardware/sam/system/libsam/cmsis/sam3s/source/templates/gcc/startup_sam3s.c
+++ b/hardware/sam/system/libsam/cmsis/sam3s/source/templates/gcc/startup_sam3s.c
@@ -73,7 +73,7 @@ IntFunc exception_table[] = {
 
     /* Configure Initial Stack Pointer, using linker-generated symbols */
     (IntFunc)(&pdwStack[STACK_SIZE-1]),
-    ResetException,
+    Reset_Handler,
 
     NMI_Handler,
     HardFault_Handler,
@@ -134,7 +134,7 @@ IntFunc exception_table[] = {
  * \brief This is the code that gets called on processor reset.
  * To initialize the device, and call the main() routine.
  */
-void ResetException( void )
+void Reset_Handler( void )
 {
     uint32_t *pSrc, *pDest ;
 
diff --git a/hardware/sam/system/libsam/cmsis/sam3s/source/templates/system_sam3s.c b/hardware/sam/system/libsam/cmsis/sam3s/source/templates/system_sam3s.c
index 06fb57631..7034b0902 100644
--- a/hardware/sam/system/libsam/cmsis/sam3s/source/templates/system_sam3s.c
+++ b/hardware/sam/system/libsam/cmsis/sam3s/source/templates/system_sam3s.c
@@ -132,7 +132,7 @@ extern void SystemCoreClockUpdate( void )
 				break;
 			}
 		}
-		if (PMC->PMC_MCKR & PMC_MCKR_CSS_Msk == PMC_MCKR_CSS_PLLA_CLK) {
+		if ((PMC->PMC_MCKR & PMC_MCKR_CSS_Msk) == PMC_MCKR_CSS_PLLA_CLK) {
 			SystemCoreClock *= ((((PMC->CKGR_PLLAR) >> CKGR_PLLAR_MULA_Pos) & 0x7FF) + 1);
 			SystemCoreClock /= ((((PMC->CKGR_PLLAR) >> CKGR_PLLAR_DIVA_Pos) & 0x0FF));
 		}
diff --git a/hardware/sam/variants/common/UART.h b/hardware/sam/variants/common/UART.h
index 6f77ff9cf..ccf5f18e6 100644
--- a/hardware/sam/variants/common/UART.h
+++ b/hardware/sam/variants/common/UART.h
@@ -26,9 +26,12 @@ class UARTClass : public HardwareSerial
 
     void IrqHandler( void ) ;
 
+#if defined __GNUC__ /* GCC CS3 */
+    using Print::write ; // pull in write(str) and write(buf, size) from Print
+#elif defined __ICCARM__ /* IAR Ewarm 5.41+ */
     virtual void write( const char *str ) ;
     virtual void write( const uint8_t *buffer, size_t size ) ;
-//    using Print::write ; // pull in write(str) and write(buf, size) from Print
+#endif
 };
 
 #endif // _UART_CLASS_
diff --git a/hardware/sam/variants/common/USART.h b/hardware/sam/variants/common/USART.h
index 1cd638580..197ffeb65 100644
--- a/hardware/sam/variants/common/USART.h
+++ b/hardware/sam/variants/common/USART.h
@@ -26,9 +26,12 @@ class USARTClass : public HardwareSerial
 
     void IrqHandler( void ) ;
 
+#if defined __GNUC__ /* GCC CS3 */
+    using Print::write ; // pull in write(str) and write(buf, size) from Print
+#elif defined __ICCARM__ /* IAR Ewarm 5.41+ */
     virtual void write( const char *str ) ;
     virtual void write( const uint8_t *buffer, size_t size ) ;
-//    using Print::write ; // pull in write(str) and write(buf, size) from Print
+#endif
 };
 
 #endif // _USART_CLASS_
diff --git a/hardware/sam/variants/sam3s_ek/build_gcc/libvariant_sam3s_ek.mk b/hardware/sam/variants/sam3s_ek/build_gcc/libvariant_sam3s_ek.mk
index 684a60cc9..9c225d6d7 100644
--- a/hardware/sam/variants/sam3s_ek/build_gcc/libvariant_sam3s_ek.mk
+++ b/hardware/sam/variants/sam3s_ek/build_gcc/libvariant_sam3s_ek.mk
@@ -139,7 +139,7 @@ $(addprefix $(OUTPUT_PATH)/,$(C_OBJ)): $(OUTPUT_PATH)/%.o: %.c
 
 $(addprefix $(OUTPUT_PATH)/,$(CPP_OBJ)): $(OUTPUT_PATH)/%.o: %.cpp
 #	@$(CC) -c $(CPPFLAGS) $< -o $@
-	$(CC) -xc++ -c $(CPPFLAGS) $< -o $@
+	@$(CC) -xc++ -c $(CPPFLAGS) $< -o $@
 
 $(addprefix $(OUTPUT_PATH)/,$(A_OBJ)): $(OUTPUT_PATH)/%.o: %.s
 	@$(AS) -c $(ASFLAGS) $< -o $@
diff --git a/hardware/sam/variants/sam3s_ek/variant.h b/hardware/sam/variants/sam3s_ek/variant.h
index ba39bfbef..35838a686 100644
--- a/hardware/sam/variants/sam3s_ek/variant.h
+++ b/hardware/sam/variants/sam3s_ek/variant.h
@@ -33,10 +33,10 @@
 /** Name of the board */
 #define VARIANT_NAME "SAM3S-EK"
 
-/*
 #define VARIANT_REV_A
-*/
+/*
 #define VARIANT_REV_B
+*/
 
 /** Frequency of the board main oscillator */
 #define VARIANT_MAINOSC           12000000