diff --git a/Makefile.stk525 b/Makefile.stk525
new file mode 100644
index 0000000..8cad8c4
--- /dev/null
+++ b/Makefile.stk525
@@ -0,0 +1,44 @@
+CC=avr-gcc
+AS=$(CC)
+LD=$(CC)
+
+PROGNAME=n64
+OBJDIR=objs-$(PROGNAME)
+CPU=at90usb1287
+CFLAGS=-Wall -mmcu=$(CPU) -DF_CPU=16000000L -Os -DUART1_STDOUT -DSTK525
+LDFLAGS=-mmcu=$(CPU) -Wl,-Map=$(PROGNAME).map
+HEXFILE=$(PROGNAME).hex
+
+OBJS=main.o n64.o gcn64_protocol.o usart1.o usb.o bootloader.o
+
+all: $(HEXFILE)
+
+clean:
+	rm -f $(PROGNAME).elf $(PROGNAME).hex $(PROGNAME).map $(OBJS)
+
+%.o: %.S
+	$(CC) $(CFLAGS) -c $< -o $@
+
+%.o: %.c
+	$(CC) $(CFLAGS) -c $< -o $@
+
+%.o: %.c %.h
+	$(CC) $(CFLAGS) -c $< -o $@
+
+$(PROGNAME).elf: $(OBJS)
+	$(LD) $(OBJS) $(LDFLAGS) -o $(PROGNAME).elf
+
+$(PROGNAME).hex: $(PROGNAME).elf
+	avr-objcopy -j .data -j .text -O ihex $(PROGNAME).elf $(PROGNAME).hex
+	avr-size $(PROGNAME).elf
+
+fuse:
+
+flash: $(HEXFILE)
+	./wait_then_flash.sh $(CPU) $(HEXFILE)
+
+chip_erase:
+	dfu-programmer atmega32u2 erase
+
+reset:
+	dfu-programmer atmega32u2 reset
diff --git a/gcn64_protocol.c b/gcn64_protocol.c
index b479c01..cea1356 100644
--- a/gcn64_protocol.c
+++ b/gcn64_protocol.c
@@ -26,13 +26,23 @@
 static volatile unsigned char gcn64_workbuf[GCN64_BUF_SIZE];
 
 /******** IO port definitions and options **************/
-#define GCN64_DATA_PORT	PORTD
-#define GCN64_DATA_DDR	DDRD
-#define GCN64_DATA_PIN	PIND
-#define GCN64_DATA_BIT	(1<<0)
-#define GCN64_BIT_NUM_S	"0" // for asm
-#define FREQ_IS_16MHZ
-#define DISABLE_INTS_DURING_COMM
+#ifndef STK525
+	#define GCN64_DATA_PORT	PORTD
+	#define GCN64_DATA_DDR	DDRD
+	#define GCN64_DATA_PIN	PIND
+	#define GCN64_DATA_BIT	(1<<0)
+	#define GCN64_BIT_NUM_S	"0" // for asm
+	#define FREQ_IS_16MHZ
+	#define DISABLE_INTS_DURING_COMM
+#else
+	#define GCN64_DATA_PORT	PORTA
+	#define GCN64_DATA_DDR	DDRA
+	#define GCN64_DATA_PIN	PINA
+	#define GCN64_DATA_BIT	(1<<0)
+	#define GCN64_BIT_NUM_S	"0" // for asm
+	#define FREQ_IS_16MHZ
+	#define DISABLE_INTS_DURING_COMM
+#endif
 
 /*
  * \brief Explode bytes to bits