diff --git a/apps/jukebox1/Makefile b/apps/jukebox1/Makefile
new file mode 100644
index 0000000..e952a2a
--- /dev/null
+++ b/apps/jukebox1/Makefile
@@ -0,0 +1,86 @@
+# File:   Makefile
+# Author: M. P. Hayes, UCECE
+# Date:   12 Sep 2010
+# Descr:  Makefile for jukebox1
+
+# Definitions.
+CC = avr-gcc
+CFLAGS = -mmcu=atmega32u2 -Os -Wall -Wstrict-prototypes -Wextra -g -I../../drivers/avr -I../../extra -I../../drivers -I../../fonts -I../../utils
+OBJCOPY = avr-objcopy
+SIZE = avr-size
+DEL = rm
+
+
+# Default target.
+all: jukebox1.out
+
+
+# Compile: create object files from C source files.
+jukebox1.o: jukebox1.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer.h ../../drivers/display.h ../../drivers/led.h ../../drivers/navswitch.h ../../extra/mmelody.h ../../extra/ticker.h ../../extra/tweeter.h ../../fonts/font3x5_1.h ../../utils/font.h ../../utils/task.h ../../utils/tinygl.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+pio.o: ../../drivers/avr/pio.c ../../drivers/avr/pio.h ../../drivers/avr/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+system.o: ../../drivers/avr/system.c ../../drivers/avr/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+timer.o: ../../drivers/avr/timer.c ../../drivers/avr/system.h ../../drivers/avr/timer.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+display.o: ../../drivers/display.c ../../drivers/avr/system.h ../../drivers/display.h ../../drivers/ledmat.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+led.o: ../../drivers/led.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/led.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+ledmat.o: ../../drivers/ledmat.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/ledmat.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+navswitch.o: ../../drivers/navswitch.c ../../drivers/avr/delay.h ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/navswitch.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+mmelody.o: ../../extra/mmelody.c ../../drivers/avr/system.h ../../extra/mmelody.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+ticker.o: ../../extra/ticker.c
+	$(CC) -c $(CFLAGS) $< -o $@
+
+tweeter.o: ../../extra/tweeter.c ../../drivers/avr/system.h ../../extra/ticker.h ../../extra/tweeter.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+font.o: ../../utils/font.c ../../drivers/avr/system.h ../../utils/font.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+task.o: ../../utils/task.c ../../drivers/avr/system.h ../../drivers/avr/timer.h ../../utils/task.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+tinygl.o: ../../utils/tinygl.c ../../drivers/avr/system.h ../../drivers/display.h ../../utils/font.h ../../utils/tinygl.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+
+
+
+# Link: create output file (executable) from object files.
+jukebox1.out: jukebox1.o pio.o system.o timer.o display.o led.o ledmat.o navswitch.o mmelody.o ticker.o tweeter.o font.o task.o tinygl.o
+	$(CC) $(CFLAGS) $^ -o $@ -lm
+	$(SIZE) $@
+
+
+# Create hex file for programming from executable file.
+jukebox1.hex: jukebox1.out
+	$(OBJCOPY) -O ihex jukebox1.out jukebox1.hex
+
+
+# Target: clean project.
+.PHONY: clean
+clean: 
+	-$(DEL) *.o *.out *.hex
+
+
+# Target: program project.
+.PHONY: program
+program: jukebox1.hex
+	dfu-programmer atmega32u2 erase; dfu-programmer atmega32u2 flash jukebox1.hex; dfu-programmer atmega32u2 start
+
+
diff --git a/apps/jukebox1/Makefile.test b/apps/jukebox1/Makefile.test
new file mode 100644
index 0000000..6da8408
--- /dev/null
+++ b/apps/jukebox1/Makefile.test
@@ -0,0 +1,76 @@
+# File:   Makefile
+# Author: M. P. Hayes, UCECE
+# Date:   11 Sep 2010
+# Descr:  Makefile for jukebox1
+
+CC = gcc
+CFLAGS = -Wall -Wstrict-prototypes -Wextra -g -I../../drivers/test -I../../drivers -I../../extra -I../../fonts -I../../utils
+
+DEL = rm
+
+
+# Default target.
+all: jukebox1
+
+
+# Compile: create object files from C source files.
+jukebox1-test.o: jukebox1.c ../../drivers/display.h ../../drivers/led.h ../../drivers/navswitch.h ../../drivers/test/avrtest.h ../../drivers/test/pio.h ../../drivers/test/system.h ../../drivers/test/timer.h ../../extra/mmelody.h ../../extra/ticker.h ../../extra/tweeter.h ../../fonts/font3x5_1.h ../../utils/font.h ../../utils/task.h ../../utils/tinygl.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+display-test.o: ../../drivers/display.c ../../drivers/display.h ../../drivers/ledmat.h ../../drivers/test/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+led-test.o: ../../drivers/led.c ../../drivers/led.h ../../drivers/test/avrtest.h ../../drivers/test/pio.h ../../drivers/test/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+ledmat-test.o: ../../drivers/ledmat.c ../../drivers/ledmat.h ../../drivers/test/avrtest.h ../../drivers/test/pio.h ../../drivers/test/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+navswitch-test.o: ../../drivers/navswitch.c ../../drivers/navswitch.h ../../drivers/test/avrtest.h ../../drivers/test/delay.h ../../drivers/test/pio.h ../../drivers/test/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+mgetkey-test.o: ../../drivers/test/mgetkey.c ../../drivers/test/mgetkey.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+pio-test.o: ../../drivers/test/pio.c ../../drivers/test/avrtest.h ../../drivers/test/pio.h ../../drivers/test/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+system-test.o: ../../drivers/test/system.c ../../drivers/test/avrtest.h ../../drivers/test/mgetkey.h ../../drivers/test/pio.h ../../drivers/test/system.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+timer-test.o: ../../drivers/test/timer.c ../../drivers/test/system.h ../../drivers/test/timer.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+mmelody-test.o: ../../extra/mmelody.c ../../drivers/test/system.h ../../extra/mmelody.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+ticker-test.o: ../../extra/ticker.c
+	$(CC) -c $(CFLAGS) $< -o $@
+
+tweeter-test.o: ../../extra/tweeter.c ../../drivers/test/system.h ../../extra/ticker.h ../../extra/tweeter.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+font-test.o: ../../utils/font.c ../../drivers/test/system.h ../../utils/font.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+task-test.o: ../../utils/task.c ../../drivers/test/system.h ../../drivers/test/timer.h ../../utils/task.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+tinygl-test.o: ../../utils/tinygl.c ../../drivers/display.h ../../drivers/test/system.h ../../utils/font.h ../../utils/tinygl.h
+	$(CC) -c $(CFLAGS) $< -o $@
+
+
+
+
+# Link: create executable file from object files.
+jukebox1: jukebox1-test.o display-test.o led-test.o ledmat-test.o navswitch-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o ticker-test.o tweeter-test.o font-test.o task-test.o tinygl-test.o
+	$(CC) $(CFLAGS) $^ -o $@ -lrt
+
+
+# Clean: delete derived files.
+.PHONY: clean
+clean: 
+	-$(DEL) jukebox1 jukebox1-test.o display-test.o led-test.o ledmat-test.o navswitch-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o ticker-test.o tweeter-test.o font-test.o task-test.o tinygl-test.o
+
+
+
diff --git a/apps/jukebox1/doc/Makefile b/apps/jukebox1/doc/Makefile
new file mode 100644
index 0000000..eb29a6d
--- /dev/null
+++ b/apps/jukebox1/doc/Makefile
@@ -0,0 +1,45 @@
+# File:   Makefile
+# Author: M. P. Hayes, UCECE
+# Date:   11 Sep 2010
+# Descr:  Makefile for squeak4 docs
+
+# The scripts used to make the graphs require the program dot; this
+# is part of the graphviz package.
+
+DEL = rm
+
+all: file_dependencies.pdf module_dependencies.pdf makefile_dependencies.pdf build_dependencies.pdf callgraph.pdf
+
+file_dependencies.pdf: files.d 
+	../../../etc/graphdeps.py $< --out $@
+
+module_dependencies.pdf: modules.d 
+	../../../etc/graphdeps.py $< --modules --rotate --out $@
+
+makefile_dependencies.pdf: ../Makefile
+	../../../etc/graphdeps.py $< --out $@
+
+build_dependencies.pdf: ../Makefile
+	../../../etc/graphdeps.py $< --out $@ --showops
+
+callgraph.pdf: callgraph.d
+	../../../etc/graphdeps.py --calls --modules $< --out $@ --showops
+
+
+files.d: ../Makefile
+	(cd ..;	../../etc/makemake.py --relpath --files . . ../../drivers ../../drivers/avr ../../utils ../../extra --exclude system.h > doc/files.d)
+
+
+modules.d: ../Makefile
+	(cd ..;	../../etc/makemake.py --relpath --modules . . ../../drivers ../../drivers/avr ../../utils ../../extra --exclude system > doc/modules.d)
+
+
+callgraph.d: ../Makefile
+	(cd ..;	../../etc/makemake.py --cc="avr-gcc" --cflags="-Os -mmcu=atmega32u2" --relpath --calls . . ../../drivers ../../drivers/avr ../../utils ../../extra --exclude system.h > doc/callgraph.d)
+
+
+# Clean: delete derived files.
+.PHONY: clean
+clean: 
+	-$(DEL) *.d *.pdf
+
diff --git a/apps/jukebox1/doc/README b/apps/jukebox1/doc/README
new file mode 100644
index 0000000..39a9712
--- /dev/null
+++ b/apps/jukebox1/doc/README
@@ -0,0 +1,16 @@
+Running make in this directory will generate a number of PDF graphs.
+In the callgraph, the arrows means "calls".  In the dependency graphs,
+the arrows means "requires" (or "depends upon").
+
+callgraph.pdf             This shows the callgraph, i.e., what functions each
+                          function in the program calls.
+module_dependencies.pdf   This shows the dependencies between the modules.
+file_dependencies.pdf     This shows the dependencies between the files.
+makefile_dependencies.pdf This shows the dependencies required by make when
+                          building the program.
+build_dependencies.pdf    This is like makefile_dependencies.pdf but shows
+                          the operations performed to generate the new file.
+
+callgraph.d               This shows the callgraph in text format.
+files.d                   This shows the file dependencies in text format.
+modules.d                 This shows the module dependencies in text format.
diff --git a/apps/jukebox1/electric.mmel b/apps/jukebox1/electric.mmel
new file mode 100644
index 0000000..163e3fe
--- /dev/null
+++ b/apps/jukebox1/electric.mmel
@@ -0,0 +1 @@
+"<C3CG/A#2A#F3/CCG/A#2A#A#4E>6<F2FE3CF2FF3CF2FG3CF2FA3C>2<C3CG/A#2A#F3/CCG/A#2A#A#4E>6<F2FE3CF2FF3CF2FG3CF2FA3C>2<G2D3FD/DAC4A3/FC4ECC3GC4B3>6<G3D4GF/DFE/CCB3C4B3C4B3>3GD4GF/DFE/<C3CG/A#2A#F3/CCG/A#2A#A#4E>6<F2FE3CF2FF3CF2FG3CF2FA3C>2<C3CG/A#2A#F3/CCG/A#2A#A#4E>6<F2FE3CF2FF3CF2FG3CF2FA3C>2CCG/A#2A#F3/CCG/A#2A#A#4E<F2FE3CF2FF3CF2FG3CF2FA3C>2<G2D3FD/DAC4A3/FC4ECC3GC4B3>6<G3D4GFD/FE/CCB3C4B3C4B3>2GD4GFDFE<C3CG/A#2A#F3/CCG/A#2A#A#4E>3C3GA#2F3CGA#2A#3AA#AFD#"
diff --git a/apps/jukebox1/imperial_march.mmel b/apps/jukebox1/imperial_march.mmel
new file mode 100644
index 0000000..6c4b789
--- /dev/null
+++ b/apps/jukebox1/imperial_march.mmel
@@ -0,0 +1 @@
+"*8<G///>3<D#//A#G///>2 ///D+///D+///D+///D#+//A#F#///D#//A#G/// ///"
diff --git a/apps/jukebox1/jukebox1.c b/apps/jukebox1/jukebox1.c
new file mode 100644
index 0000000..2baccff
--- /dev/null
+++ b/apps/jukebox1/jukebox1.c
@@ -0,0 +1,171 @@
+/** @file   squeak4.c
+    @author M.P. Hayes
+    @date   30 Aug 2011
+*/
+
+#include "system.h"
+#include "navswitch.h"
+#include "led.h"
+#include "pio.h"
+#include "task.h"
+#include "tweeter.h"
+#include "mmelody.h"
+#include "tinygl.h"
+#include "../fonts/font3x5_1.h"
+
+
+/* Connect piezo tweeter to outermost pins of UCFK4 P1 connector.  */
+#define PIEZO_PIO PIO_DEFINE (PORT_D, 6)
+
+/* Define polling rates in Hz.  */
+#define TWEETER_TASK_RATE 20000
+
+#define TUNE_TASK_RATE 200
+
+#define NAVSWITCH_TASK_RATE 10
+
+#define TUNE_BPM_RATE 200
+
+#define LED_TASK_RATE (TUNE_BPM_RATE / 60.0)
+
+#define DISPLAY_TASK_RATE 200
+
+
+static tweeter_scale_t scale_table[] = TWEETER_SCALE_TABLE (TWEETER_TASK_RATE);
+static tweeter_t tweeter;
+static mmelody_t melody;
+static mmelody_obj_t melody_info;
+static tweeter_obj_t tweeter_info;
+static char *note_names[] = {"C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"};
+
+static const char tune1[] =
+{
+#include "electric.mmel"
+};
+
+static const char tune2[] =
+{
+#include "temple_of_love.mmel"
+};
+
+static const char tune3[] =
+{
+#include "electric.mmel"
+};
+
+
+void
+note_play (tweeter_t tweeter, tweeter_note_t note, uint8_t velocity)
+{
+    tinygl_clear ();
+    if (note != 0 && velocity != 0)
+        tinygl_text (note_names[note % 12]);
+
+    tweeter_note_play (tweeter, note, velocity);
+}
+
+
+static void led_flash_task_init (void)
+{
+    led_init ();
+}
+
+
+static void led_flash_task (__unused__ void *data)
+{
+    static uint8_t state = 0;
+
+    led_set (LED1, state);
+    state = !state;
+}
+
+
+static void tweeter_task_init (void)
+{
+    tweeter = tweeter_init (&tweeter_info, TWEETER_TASK_RATE, scale_table);
+
+    pio_config_set (PIEZO_PIO, PIO_OUTPUT_LOW);
+}
+
+
+static void tweeter_task (__unused__ void *data)
+{
+    pio_output_set (PIEZO_PIO, tweeter_update (tweeter));
+}
+
+
+static void tune_task_init (void)
+{
+    melody = mmelody_init (&melody_info, TUNE_TASK_RATE, 
+			   (mmelody_callback_t) note_play, tweeter);
+
+    mmelody_speed_set (melody, TUNE_BPM_RATE);
+}
+
+
+static void tune_task (__unused__ void *data)
+{
+    mmelody_update (melody);
+}
+
+
+static void navswitch_task_init (void)
+{
+    navswitch_init ();
+}
+
+
+static void navswitch_task (__unused__ void *data)
+{
+    navswitch_update ();
+
+    if (navswitch_push_event_p (NAVSWITCH_PUSH))
+    {
+        mmelody_play (melody, 0);            
+    }
+    if (navswitch_push_event_p (NAVSWITCH_NORTH))
+        mmelody_play (melody, tune1);            
+    if (navswitch_push_event_p (NAVSWITCH_EAST))
+        mmelody_play (melody, tune2);            
+    if (navswitch_push_event_p (NAVSWITCH_SOUTH))
+        mmelody_play (melody, tune3);            
+}
+
+
+static void display_task_init (void)
+{
+    tinygl_init (DISPLAY_TASK_RATE);
+    tinygl_font_set (&font3x5_1);
+    tinygl_text_mode_set (TINYGL_TEXT_MODE_STEP);
+    tinygl_text_dir_set (TINYGL_TEXT_DIR_ROTATE);
+}
+
+
+static void display_task (__unused__ void *data)
+{
+    tinygl_update ();
+}
+
+
+int main (void)
+{
+    task_t tasks[] =
+    {
+        {.func = tweeter_task, .period = TASK_RATE / TWEETER_TASK_RATE, .data = 0},
+        {.func = led_flash_task, .period = TASK_RATE / LED_TASK_RATE, .data = 0},
+        {.func = tune_task, .period = TASK_RATE / TUNE_TASK_RATE, .data = 0},
+        {.func = display_task, .period = TASK_RATE / DISPLAY_TASK_RATE, .data = 0}, 
+        {.func = navswitch_task, .period = TASK_RATE / NAVSWITCH_TASK_RATE, .data = 0},
+    };
+
+    system_init ();
+
+    led_flash_task_init ();
+    tweeter_task_init ();
+    tune_task_init ();
+    display_task_init ();
+    navswitch_task_init ();
+
+    task_schedule (tasks, ARRAY_SIZE (tasks));
+    return 0;
+}
diff --git a/apps/jukebox1/temple_of_love.mmel b/apps/jukebox1/temple_of_love.mmel
new file mode 100644
index 0000000..2dd9344
--- /dev/null
+++ b/apps/jukebox1/temple_of_love.mmel
@@ -0,0 +1,3 @@
+/* E2, D4 */
+"*8E3EBBE2EB3BDDAAD4DA3AA2AE3EAABBC4CB3BAAGGEEBBE2EB3BDDAAD4DA3AA2AE3EAABBC4CB3BAABB"
+