diff --git a/apps/space12/Makefile b/apps/space12/Makefile
index 948280e..c4d63a3 100644
--- a/apps/space12/Makefile
+++ b/apps/space12/Makefile
@@ -16,7 +16,7 @@ all: space12.out
 
 
 # Compile: create object files from C source files.
-space12.o: space12.c ../../drivers/avr/eeprom.h ../../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/squeaker.h ../../extra/ticker.h ../../extra/tweeter.h ../../fonts/font3x5_1.h ../../utils/font.h ../../utils/task.h ../../utils/tinygl.h ../../utils/uint8toa.h flasher.h spacey.h
+space12.o: space12.c ../../drivers/avr/eeprom.h ../../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 ../../utils/uint8toa.h flasher.h spacey.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
 flasher.o: flasher.c ../../drivers/avr/system.h flasher.h
@@ -52,9 +52,6 @@ navswitch.o: ../../drivers/navswitch.c ../../drivers/avr/delay.h ../../drivers/a
 mmelody.o: ../../extra/mmelody.c ../../drivers/avr/system.h ../../extra/mmelody.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
-squeaker.o: ../../extra/squeaker.c ../../drivers/avr/system.h ../../extra/squeaker.h ../../extra/ticker.h
-	$(CC) -c $(CFLAGS) $< -o $@
-
 ticker.o: ../../extra/ticker.c
 	$(CC) -c $(CFLAGS) $< -o $@
 
@@ -73,7 +70,7 @@ uint8toa.o: ../../utils/uint8toa.c ../../drivers/avr/system.h
 
 
 # Link: create ELF output file from object files.
-space12.out: space12.o flasher.o spacey.o eeprom.o pio.o system.o timer.o display.o led.o ledmat.o navswitch.o mmelody.o squeaker.o ticker.o tweeter.o task.o tinygl.o uint8toa.o
+space12.out: space12.o flasher.o spacey.o eeprom.o pio.o system.o timer.o display.o led.o ledmat.o navswitch.o mmelody.o ticker.o tweeter.o task.o tinygl.o uint8toa.o
 	$(CC) $(CFLAGS) $^ -o $@ -lm
 	$(SIZE) $@
 
diff --git a/apps/space12/Makefile.test b/apps/space12/Makefile.test
index 12f8f5f..e6962c6 100644
--- a/apps/space12/Makefile.test
+++ b/apps/space12/Makefile.test
@@ -14,7 +14,7 @@ all: space12
 
 
 # Compile: create object files from C source files.
-space12-test.o: space12.c ../../drivers/display.h ../../drivers/led.h ../../drivers/navswitch.h ../../drivers/test/avrtest.h ../../drivers/test/eeprom.h ../../drivers/test/pio.h ../../drivers/test/system.h ../../drivers/test/timer.h ../../extra/mmelody.h ../../extra/squeaker.h ../../extra/ticker.h ../../extra/tweeter.h ../../fonts/font3x5_1.h ../../utils/font.h ../../utils/task.h ../../utils/tinygl.h ../../utils/uint8toa.h flasher.h spacey.h
+space12-test.o: space12.c ../../drivers/display.h ../../drivers/led.h ../../drivers/navswitch.h ../../drivers/test/avrtest.h ../../drivers/test/eeprom.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 ../../utils/uint8toa.h flasher.h spacey.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
 flasher-test.o: flasher.c ../../drivers/test/system.h flasher.h
@@ -53,9 +53,6 @@ timer-test.o: ../../drivers/test/timer.c ../../drivers/test/system.h ../../drive
 mmelody-test.o: ../../extra/mmelody.c ../../drivers/test/system.h ../../extra/mmelody.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
-squeaker-test.o: ../../extra/squeaker.c ../../drivers/test/system.h ../../extra/squeaker.h ../../extra/ticker.h
-	$(CC) -c $(CFLAGS) $< -o $@
-
 ticker-test.o: ../../extra/ticker.c
 	$(CC) -c $(CFLAGS) $< -o $@
 
@@ -75,14 +72,14 @@ uint8toa-test.o: ../../utils/uint8toa.c ../../drivers/test/system.h
 
 
 # Link: create executable file from object files.
-space12: space12-test.o flasher-test.o spacey-test.o display-test.o led-test.o ledmat-test.o navswitch-test.o eeprom-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o squeaker-test.o ticker-test.o tweeter-test.o task-test.o tinygl-test.o uint8toa-test.o
+space12: space12-test.o flasher-test.o spacey-test.o display-test.o led-test.o ledmat-test.o navswitch-test.o eeprom-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o ticker-test.o tweeter-test.o task-test.o tinygl-test.o uint8toa-test.o
 	$(CC) $(CFLAGS) $^ -o $@ -lrt
 
 
 # Clean: delete derived files.
 .PHONY: clean
 clean: 
-	-$(DEL) space12 space12-test.o flasher-test.o spacey-test.o display-test.o led-test.o ledmat-test.o navswitch-test.o eeprom-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o squeaker-test.o ticker-test.o tweeter-test.o task-test.o tinygl-test.o uint8toa-test.o
+	-$(DEL) space12 space12-test.o flasher-test.o spacey-test.o display-test.o led-test.o ledmat-test.o navswitch-test.o eeprom-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o ticker-test.o tweeter-test.o task-test.o tinygl-test.o uint8toa-test.o
 
 
 
diff --git a/apps/space12/imperial_march.mmel b/apps/space12/imperial_march.mmel
index 4493630..6c4b789 100644
--- a/apps/space12/imperial_march.mmel
+++ b/apps/space12/imperial_march.mmel
@@ -1 +1 @@
-"*16<G///>3<D#//A#G///>2 ///D+///D+///D+///D#+//A#F#///D#//A#G/// ///"
+"*8<G///>3<D#//A#G///>2 ///D+///D+///D+///D#+//A#F#///D#//A#G/// ///"
diff --git a/apps/space12/space12.c b/apps/space12/space12.c
index b29cc0e..fd8f7f0 100644
--- a/apps/space12/space12.c
+++ b/apps/space12/space12.c
@@ -19,7 +19,6 @@
 #include "uint8toa.h"
 #include "../fonts/font3x5_1.h"
 #include "tweeter.h"
-#include "squeaker.h"
 #include "mmelody.h"
 #include "pio.h"
 
diff --git a/apps/squeak1/Makefile b/apps/squeak1/Makefile
index 46ac251..6b73258 100644
--- a/apps/squeak1/Makefile
+++ b/apps/squeak1/Makefile
@@ -16,7 +16,7 @@ all: squeak1.out
 
 
 # Compile: create object files from C source files.
-squeak1.o: squeak1.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer.h ../../drivers/led.h ../../extra/mmelody.h ../../extra/squeaker.h ../../extra/ticker.h ../../extra/tweeter.h ../../utils/task.h
+squeak1.o: squeak1.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer.h ../../drivers/led.h ../../extra/mmelody.h ../../extra/ticker.h ../../extra/tweeter.h ../../utils/task.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
 pio.o: ../../drivers/avr/pio.c ../../drivers/avr/pio.h ../../drivers/avr/system.h
@@ -34,9 +34,6 @@ led.o: ../../drivers/led.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ..
 mmelody.o: ../../extra/mmelody.c ../../drivers/avr/system.h ../../extra/mmelody.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
-squeaker.o: ../../extra/squeaker.c ../../drivers/avr/system.h ../../extra/squeaker.h ../../extra/ticker.h
-	$(CC) -c $(CFLAGS) $< -o $@
-
 ticker.o: ../../extra/ticker.c
 	$(CC) -c $(CFLAGS) $< -o $@
 
@@ -49,7 +46,7 @@ task.o: ../../utils/task.c ../../drivers/avr/system.h ../../drivers/avr/timer.h
 
 
 # Link: create ELF output file from object files.
-squeak1.out: squeak1.o pio.o system.o timer.o led.o mmelody.o squeaker.o ticker.o tweeter.o task.o
+squeak1.out: squeak1.o pio.o system.o timer.o led.o mmelody.o ticker.o tweeter.o task.o
 	$(CC) $(CFLAGS) $^ -o $@ -lm
 	$(SIZE) $@
 
diff --git a/apps/squeak1/Makefile.test b/apps/squeak1/Makefile.test
index 125a10e..bf07ef8 100644
--- a/apps/squeak1/Makefile.test
+++ b/apps/squeak1/Makefile.test
@@ -14,7 +14,7 @@ all: squeak1
 
 
 # Compile: create object files from C source files.
-squeak1-test.o: squeak1.c ../../drivers/led.h ../../drivers/test/avrtest.h ../../drivers/test/pio.h ../../drivers/test/system.h ../../drivers/test/timer.h ../../extra/mmelody.h ../../extra/squeaker.h ../../extra/ticker.h ../../extra/tweeter.h ../../utils/task.h
+squeak1-test.o: squeak1.c ../../drivers/led.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 ../../utils/task.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
@@ -35,9 +35,6 @@ timer-test.o: ../../drivers/test/timer.c ../../drivers/test/system.h ../../drive
 mmelody-test.o: ../../extra/mmelody.c ../../drivers/test/system.h ../../extra/mmelody.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
-squeaker-test.o: ../../extra/squeaker.c ../../drivers/test/system.h ../../extra/squeaker.h ../../extra/ticker.h
-	$(CC) -c $(CFLAGS) $< -o $@
-
 ticker-test.o: ../../extra/ticker.c
 	$(CC) -c $(CFLAGS) $< -o $@
 
@@ -51,14 +48,14 @@ task-test.o: ../../utils/task.c ../../drivers/test/system.h ../../drivers/test/t
 
 
 # Link: create executable file from object files.
-squeak1: squeak1-test.o led-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o squeaker-test.o ticker-test.o tweeter-test.o task-test.o
+squeak1: squeak1-test.o led-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o ticker-test.o tweeter-test.o task-test.o
 	$(CC) $(CFLAGS) $^ -o $@ -lrt
 
 
 # Clean: delete derived files.
 .PHONY: clean
 clean: 
-	-$(DEL) squeak1 squeak1-test.o led-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o squeaker-test.o ticker-test.o tweeter-test.o task-test.o
+	-$(DEL) squeak1 squeak1-test.o led-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o ticker-test.o tweeter-test.o task-test.o
 
 
 
diff --git a/apps/squeak1/squeak1.c b/apps/squeak1/squeak1.c
index 9da9b4f..ea62753 100644
--- a/apps/squeak1/squeak1.c
+++ b/apps/squeak1/squeak1.c
@@ -8,7 +8,6 @@
 #include "pio.h"
 #include "task.h"
 #include "tweeter.h"
-#include "squeaker.h"
 #include "mmelody.h"
 
 
diff --git a/apps/squeak2/Makefile b/apps/squeak2/Makefile
index b09976d..cd5ffd8 100644
--- a/apps/squeak2/Makefile
+++ b/apps/squeak2/Makefile
@@ -16,7 +16,7 @@ all: squeak2.out
 
 
 # Compile: create object files from C source files.
-squeak2.o: squeak2.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer.h ../../drivers/button.h ../../drivers/led.h ../../extra/mmelody.h ../../extra/squeaker.h ../../extra/ticker.h ../../extra/tweeter.h ../../utils/task.h
+squeak2.o: squeak2.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer.h ../../drivers/button.h ../../drivers/led.h ../../extra/mmelody.h ../../extra/ticker.h ../../extra/tweeter.h ../../utils/task.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
 pio.o: ../../drivers/avr/pio.c ../../drivers/avr/pio.h ../../drivers/avr/system.h
@@ -37,9 +37,6 @@ led.o: ../../drivers/led.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ..
 mmelody.o: ../../extra/mmelody.c ../../drivers/avr/system.h ../../extra/mmelody.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
-squeaker.o: ../../extra/squeaker.c ../../drivers/avr/system.h ../../extra/squeaker.h ../../extra/ticker.h
-	$(CC) -c $(CFLAGS) $< -o $@
-
 ticker.o: ../../extra/ticker.c
 	$(CC) -c $(CFLAGS) $< -o $@
 
@@ -52,7 +49,7 @@ task.o: ../../utils/task.c ../../drivers/avr/system.h ../../drivers/avr/timer.h
 
 
 # Link: create ELF output file from object files.
-squeak2.out: squeak2.o pio.o system.o timer.o button.o led.o mmelody.o squeaker.o ticker.o tweeter.o task.o
+squeak2.out: squeak2.o pio.o system.o timer.o button.o led.o mmelody.o ticker.o tweeter.o task.o
 	$(CC) $(CFLAGS) $^ -o $@ -lm
 	$(SIZE) $@
 
diff --git a/apps/squeak2/Makefile.test b/apps/squeak2/Makefile.test
index ba27793..f998e7b 100644
--- a/apps/squeak2/Makefile.test
+++ b/apps/squeak2/Makefile.test
@@ -14,7 +14,7 @@ all: squeak2
 
 
 # Compile: create object files from C source files.
-squeak2-test.o: squeak2.c ../../drivers/button.h ../../drivers/led.h ../../drivers/test/avrtest.h ../../drivers/test/pio.h ../../drivers/test/system.h ../../drivers/test/timer.h ../../extra/mmelody.h ../../extra/squeaker.h ../../extra/ticker.h ../../extra/tweeter.h ../../utils/task.h
+squeak2-test.o: squeak2.c ../../drivers/button.h ../../drivers/led.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 ../../utils/task.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
 button-test.o: ../../drivers/button.c ../../drivers/button.h ../../drivers/test/avrtest.h ../../drivers/test/pio.h ../../drivers/test/system.h
@@ -38,9 +38,6 @@ timer-test.o: ../../drivers/test/timer.c ../../drivers/test/system.h ../../drive
 mmelody-test.o: ../../extra/mmelody.c ../../drivers/test/system.h ../../extra/mmelody.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
-squeaker-test.o: ../../extra/squeaker.c ../../drivers/test/system.h ../../extra/squeaker.h ../../extra/ticker.h
-	$(CC) -c $(CFLAGS) $< -o $@
-
 ticker-test.o: ../../extra/ticker.c
 	$(CC) -c $(CFLAGS) $< -o $@
 
@@ -54,14 +51,14 @@ task-test.o: ../../utils/task.c ../../drivers/test/system.h ../../drivers/test/t
 
 
 # Link: create executable file from object files.
-squeak2: squeak2-test.o button-test.o led-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o squeaker-test.o ticker-test.o tweeter-test.o task-test.o
+squeak2: squeak2-test.o button-test.o led-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o ticker-test.o tweeter-test.o task-test.o
 	$(CC) $(CFLAGS) $^ -o $@ -lrt
 
 
 # Clean: delete derived files.
 .PHONY: clean
 clean: 
-	-$(DEL) squeak2 squeak2-test.o button-test.o led-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o squeaker-test.o ticker-test.o tweeter-test.o task-test.o
+	-$(DEL) squeak2 squeak2-test.o button-test.o led-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o ticker-test.o tweeter-test.o task-test.o
 
 
 
diff --git a/apps/squeak2/squeak2.c b/apps/squeak2/squeak2.c
index 830cdf8..c7ca094 100644
--- a/apps/squeak2/squeak2.c
+++ b/apps/squeak2/squeak2.c
@@ -9,7 +9,6 @@
 #include "pio.h"
 #include "task.h"
 #include "tweeter.h"
-#include "squeaker.h"
 #include "mmelody.h"
 
 
diff --git a/apps/squeak3/Makefile b/apps/squeak3/Makefile
index 7b66df8..47be8b3 100644
--- a/apps/squeak3/Makefile
+++ b/apps/squeak3/Makefile
@@ -16,7 +16,7 @@ all: squeak3.out
 
 
 # Compile: create object files from C source files.
-squeak3.o: squeak3.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer.h ../../drivers/button.h ../../drivers/display.h ../../drivers/led.h ../../drivers/navswitch.h ../../extra/squeaker.h ../../extra/ticker.h ../../extra/tweeter.h ../../fonts/font3x5_1.h ../../utils/font.h ../../utils/task.h ../../utils/tinygl.h
+squeak3.o: squeak3.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer.h ../../drivers/button.h ../../drivers/display.h ../../drivers/led.h ../../drivers/navswitch.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
@@ -43,9 +43,6 @@ ledmat.o: ../../drivers/ledmat.c ../../drivers/avr/pio.h ../../drivers/avr/syste
 navswitch.o: ../../drivers/navswitch.c ../../drivers/avr/delay.h ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/navswitch.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
-squeaker.o: ../../extra/squeaker.c ../../drivers/avr/system.h ../../extra/squeaker.h ../../extra/ticker.h
-	$(CC) -c $(CFLAGS) $< -o $@
-
 ticker.o: ../../extra/ticker.c
 	$(CC) -c $(CFLAGS) $< -o $@
 
@@ -61,7 +58,7 @@ tinygl.o: ../../utils/tinygl.c ../../drivers/avr/system.h ../../drivers/display.
 
 
 # Link: create ELF output file from object files.
-squeak3.out: squeak3.o pio.o system.o timer.o button.o display.o led.o ledmat.o navswitch.o squeaker.o ticker.o tweeter.o task.o tinygl.o
+squeak3.out: squeak3.o pio.o system.o timer.o button.o display.o led.o ledmat.o navswitch.o ticker.o tweeter.o task.o tinygl.o
 	$(CC) $(CFLAGS) $^ -o $@ -lm
 	$(SIZE) $@
 
diff --git a/apps/squeak3/Makefile.test b/apps/squeak3/Makefile.test
index 560940e..02fb841 100644
--- a/apps/squeak3/Makefile.test
+++ b/apps/squeak3/Makefile.test
@@ -14,7 +14,7 @@ all: squeak3
 
 
 # Compile: create object files from C source files.
-squeak3-test.o: squeak3.c ../../drivers/button.h ../../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/squeaker.h ../../extra/ticker.h ../../extra/tweeter.h ../../fonts/font3x5_1.h ../../utils/font.h ../../utils/task.h ../../utils/tinygl.h
+squeak3-test.o: squeak3.c ../../drivers/button.h ../../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/ticker.h ../../extra/tweeter.h ../../fonts/font3x5_1.h ../../utils/font.h ../../utils/task.h ../../utils/tinygl.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
 button-test.o: ../../drivers/button.c ../../drivers/button.h ../../drivers/test/avrtest.h ../../drivers/test/pio.h ../../drivers/test/system.h
@@ -44,9 +44,6 @@ system-test.o: ../../drivers/test/system.c ../../drivers/test/avrtest.h ../../dr
 timer-test.o: ../../drivers/test/timer.c ../../drivers/test/system.h ../../drivers/test/timer.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
-squeaker-test.o: ../../extra/squeaker.c ../../drivers/test/system.h ../../extra/squeaker.h ../../extra/ticker.h
-	$(CC) -c $(CFLAGS) $< -o $@
-
 ticker-test.o: ../../extra/ticker.c
 	$(CC) -c $(CFLAGS) $< -o $@
 
@@ -63,14 +60,14 @@ tinygl-test.o: ../../utils/tinygl.c ../../drivers/display.h ../../drivers/test/s
 
 
 # Link: create executable file from object files.
-squeak3: squeak3-test.o button-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 squeaker-test.o ticker-test.o tweeter-test.o task-test.o tinygl-test.o
+squeak3: squeak3-test.o button-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 ticker-test.o tweeter-test.o task-test.o tinygl-test.o
 	$(CC) $(CFLAGS) $^ -o $@ -lrt
 
 
 # Clean: delete derived files.
 .PHONY: clean
 clean: 
-	-$(DEL) squeak3 squeak3-test.o button-test.o display-test.o led-test.o ledmat-test.o navswitch-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o squeaker-test.o ticker-test.o tweeter-test.o task-test.o tinygl-test.o
+	-$(DEL) squeak3 squeak3-test.o button-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 ticker-test.o tweeter-test.o task-test.o tinygl-test.o
 
 
 
diff --git a/apps/squeak3/squeak3.c b/apps/squeak3/squeak3.c
index 643b2bf..5804143 100644
--- a/apps/squeak3/squeak3.c
+++ b/apps/squeak3/squeak3.c
@@ -10,7 +10,6 @@
 #include "pio.h"
 #include "task.h"
 #include "tweeter.h"
-#include "squeaker.h"
 #include "tinygl.h"
 #include "../fonts/font3x5_1.h"
 
diff --git a/apps/squeak4/Makefile b/apps/squeak4/Makefile
index 5b06753..36ab149 100644
--- a/apps/squeak4/Makefile
+++ b/apps/squeak4/Makefile
@@ -16,7 +16,7 @@ all: squeak4.out
 
 
 # Compile: create object files from C source files.
-squeak4.o: squeak4.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer.h ../../drivers/button.h ../../drivers/display.h ../../drivers/led.h ../../extra/mmelody.h ../../extra/squeaker.h ../../extra/ticker.h ../../extra/tweeter.h ../../fonts/font3x5_1.h ../../utils/font.h ../../utils/task.h ../../utils/tinygl.h
+squeak4.o: squeak4.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer.h ../../drivers/button.h ../../drivers/display.h ../../drivers/led.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
@@ -43,9 +43,6 @@ ledmat.o: ../../drivers/ledmat.c ../../drivers/avr/pio.h ../../drivers/avr/syste
 mmelody.o: ../../extra/mmelody.c ../../drivers/avr/system.h ../../extra/mmelody.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
-squeaker.o: ../../extra/squeaker.c ../../drivers/avr/system.h ../../extra/squeaker.h ../../extra/ticker.h
-	$(CC) -c $(CFLAGS) $< -o $@
-
 ticker.o: ../../extra/ticker.c
 	$(CC) -c $(CFLAGS) $< -o $@
 
@@ -61,7 +58,7 @@ tinygl.o: ../../utils/tinygl.c ../../drivers/avr/system.h ../../drivers/display.
 
 
 # Link: create ELF output file from object files.
-squeak4.out: squeak4.o pio.o system.o timer.o button.o display.o led.o ledmat.o mmelody.o squeaker.o ticker.o tweeter.o task.o tinygl.o
+squeak4.out: squeak4.o pio.o system.o timer.o button.o display.o led.o ledmat.o mmelody.o ticker.o tweeter.o task.o tinygl.o
 	$(CC) $(CFLAGS) $^ -o $@ -lm
 	$(SIZE) $@
 
diff --git a/apps/squeak4/Makefile.test b/apps/squeak4/Makefile.test
index 5dbf72c..4eb34b5 100644
--- a/apps/squeak4/Makefile.test
+++ b/apps/squeak4/Makefile.test
@@ -14,7 +14,7 @@ all: squeak4
 
 
 # Compile: create object files from C source files.
-squeak4-test.o: squeak4.c ../../drivers/button.h ../../drivers/display.h ../../drivers/led.h ../../drivers/test/avrtest.h ../../drivers/test/pio.h ../../drivers/test/system.h ../../drivers/test/timer.h ../../extra/mmelody.h ../../extra/squeaker.h ../../extra/ticker.h ../../extra/tweeter.h ../../fonts/font3x5_1.h ../../utils/font.h ../../utils/task.h ../../utils/tinygl.h
+squeak4-test.o: squeak4.c ../../drivers/button.h ../../drivers/display.h ../../drivers/led.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 $@
 
 button-test.o: ../../drivers/button.c ../../drivers/button.h ../../drivers/test/avrtest.h ../../drivers/test/pio.h ../../drivers/test/system.h
@@ -44,9 +44,6 @@ timer-test.o: ../../drivers/test/timer.c ../../drivers/test/system.h ../../drive
 mmelody-test.o: ../../extra/mmelody.c ../../drivers/test/system.h ../../extra/mmelody.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
-squeaker-test.o: ../../extra/squeaker.c ../../drivers/test/system.h ../../extra/squeaker.h ../../extra/ticker.h
-	$(CC) -c $(CFLAGS) $< -o $@
-
 ticker-test.o: ../../extra/ticker.c
 	$(CC) -c $(CFLAGS) $< -o $@
 
@@ -63,14 +60,14 @@ tinygl-test.o: ../../utils/tinygl.c ../../drivers/display.h ../../drivers/test/s
 
 
 # Link: create executable file from object files.
-squeak4: squeak4-test.o button-test.o display-test.o led-test.o ledmat-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o squeaker-test.o ticker-test.o tweeter-test.o task-test.o tinygl-test.o
+squeak4: squeak4-test.o button-test.o display-test.o led-test.o ledmat-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o ticker-test.o tweeter-test.o task-test.o tinygl-test.o
 	$(CC) $(CFLAGS) $^ -o $@ -lrt
 
 
 # Clean: delete derived files.
 .PHONY: clean
 clean: 
-	-$(DEL) squeak4 squeak4-test.o button-test.o display-test.o led-test.o ledmat-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o squeaker-test.o ticker-test.o tweeter-test.o task-test.o tinygl-test.o
+	-$(DEL) squeak4 squeak4-test.o button-test.o display-test.o led-test.o ledmat-test.o mgetkey-test.o pio-test.o system-test.o timer-test.o mmelody-test.o ticker-test.o tweeter-test.o task-test.o tinygl-test.o
 
 
 
diff --git a/apps/squeak4/squeak4.c b/apps/squeak4/squeak4.c
index 6b30289..3cc1f44 100644
--- a/apps/squeak4/squeak4.c
+++ b/apps/squeak4/squeak4.c
@@ -9,7 +9,6 @@
 #include "pio.h"
 #include "task.h"
 #include "tweeter.h"
-#include "squeaker.h"
 #include "mmelody.h"
 #include "tinygl.h"
 #include "../fonts/font3x5_1.h"
diff --git a/extra/squeaker.c b/extra/squeaker.c
deleted file mode 100644
index 2a912ea..0000000
--- a/extra/squeaker.c
+++ /dev/null
@@ -1,436 +0,0 @@
-/** @file   squeaker.c
-    @author M. P. Hayes, UCECE
-    @date   14 April 2007
-    @brief  Play simple tunes with PWM.
-*/
-
-#define SQUEAKER_TRANSPARENT 1
-
-#include "squeaker.h"
-
-
-#define SQUEAKER_HOLDOFF_TIME 50e-3
-enum {SQUEAKER_PRESCALER = 256};
-
-
-/* By default notes are in the scale C4 -> C5.
-   Note the first 12 frets on a six string guitar covers 3 octaves
-   from the pitch E2 (82.41 Hz) to the pitch E5 (659.26 Hz).
-
-   Tunes are specified using the notation C4C5F4G4C4 but for brevity
-   this can be simplified to C4C5F4GC where the previously specified
-   octave number persists.  A problem with this notation is the
-   verbosity when we have something like B2C3B2C3.  Most melodies will
-   only require 2 and 3 at the most octaves.  The ABC music notation
-   uses CDEFGABcdefgabc'd'e'f'g'a'b'c' to denote 3 octaves from C2 to
-   C5?  This uses numbers to indicate note duration, for example, C2
-   denotes a C of twice the standard duration.
-
-   For emphasis of first beat in bar, perhaps use ^ to indicate
-   louder, for example, C^.  Similarly, to make a note quieter it
-   could have a v suffix.  Alternatively, | bar markers could be
-   inserted and perhaps time signatures.
-
-   By default notes are quarter-notes.  It is probably best to define
-   speed in terms of quarter-notes (beats per minute) rather than bars
-   per minute since this requires bars to be defined.  Two bars in 4/4
-   could be represented by C^DEDC^BAB whereas two bars in 3/4 could be
-   represented by C^DEC^DE.
-   
-   So how should we denote note duration?  We need to distinguish
-   between 2 identical quarter-notes (A A) played in succession and a
-   half-note since this sounds different.
-
-   We could use AA to indicate two A quarter-notes.  Alternatively, we
-   could use AA to indicate an A half-note.  However, for a whole note
-   we would need to indicate this with AAAA.  With the latter scheme
-   we could separate two indentical quarter notes with a comma, for
-   example, A,A.
-
-   Rests are easy.  Each space represents one rest of quarter-note
-   duration.  Two spaces represent a half-note rest.  Alternatively,
-   we could represent this with " /".
-
-   From a sequencing point of view it is simpler if every symbol
-   represents a quarter-note rather than having variable length notes
-   since this alters the sequencing timing.  This favours the approach
-   of using AA to denote a half-note.
-
-   If I implement a simple attack/decay response then it would be
-   easier to use A/ for a half-note since we would interpret the / as
-   to keep playing the previous note without sounding it again.
-   Alternatively, when each new note is sounded there could be a short
-   delay.
-
-   >num could indicate jump forward to label num while <num could
-   represent jump back to label num.  Although I prefer the notation
-   <ABC>3 to represent playing the notes ABC in succession 3 times.
-   This notation could be nested, for example, <ABC<DEF>2>3.
-   Perhaps <ABC> denotes playing ABC indefinitely?  No I prefer
-   a simple repeat.  Use ABC: for an infinite repeat.
-
-   <ABC]1DE]2FG> represents ABCDEABCFG where ]n denotes alternate
-   endings.  
-
-*/
-
-
-
-static void
-squeaker_ticker_set (squeaker_t squeaker)
-{
-    uint16_t speed;
-
-    speed = squeaker->speed * squeaker->note_fraction;
-
-#if 0
-    /* The division is performed first to reduce the chance of integer
-       overflow.  This results in poorer accuracy when the poll_rate
-       is low.  In practice, the poll_rate cannot be too low otherwise
-       the generated notes will be inaccurate.  */
-    TICKER_INIT (&squeaker->ticker, (squeaker->poll_rate / speed) * 60);
-#else
-    TICKER_INIT (&squeaker->ticker, (squeaker->poll_rate / SQUEAKER_PRESCALER)
-                 * 60 / speed);
-#endif
-}
-
-
-/* Specify the default note length in fractions of a measure (bar).
-   A value of 4 is the default which makes each note a quarter note.  */
-static void 
-squeaker_note_fraction_set (squeaker_t squeaker, uint8_t note_fraction)
-{
-    squeaker->note_fraction = note_fraction;    
-    squeaker_ticker_set (squeaker);
-}
-
-
-enum {SQUEAKER_SCALE_SIZE = 12};
-
-void 
-squeaker_note_set (squeaker_t squeaker, 
-                   squeaker_period_t period,
-                   squeaker_period_t duty)
-{
-    squeaker->note_period = period;
-    squeaker->note_duty = duty;
-    squeaker->note_holdoff = squeaker->holdoff;
-}
-
-
-static void
-squeaker_rest_play (squeaker_t squeaker)
-{
-    squeaker_note_set (squeaker, 0, 0);
-}
-
-
-static void
-squeaker_note_play (squeaker_t squeaker, squeaker_note_t note)
-{
-    squeaker_period_t period;
-    squeaker_period_t duty;
-    uint8_t index;
-    uint8_t octave;
-
-#if 0
-    /* See if we can play this note.  */
-    if (note < SQUEAKER_NOTE_MIN)
-        return;
-#endif
-
-    note -= SQUEAKER_NOTE_MIN;
-    octave = note / SQUEAKER_SCALE_SIZE;
-    index = note - octave * SQUEAKER_SCALE_SIZE;
-
-    period = squeaker->scale_table[index];
-    
-    while (octave-- > 0)
-        period >>= 1;
-
-    duty = (period * squeaker->volume) >> 8;
-
-    squeaker_note_set (squeaker, period, duty);
-
-#if 0
-    printf ("note = %d, octave = %d, period = %d\n",
-            note, index / SQUEAKER_SCALE_SIZE, period);
-#endif
-}
-
-
-static squeaker_note_t
-squeaker_char_to_note (uint8_t ch)
-{
-    squeaker_note_t note;
-    /* A = 9, B = 11, C = 0, D = 2, E = 4, F = 5, G = 7  */
-    static const squeaker_note_t const lookup[] = {9, 11, 0, 2, 4, 5, 7};
-
-    return lookup[ch - 'A'];
-
-#if 0
-
-    switch (ch)
-    {
-    default:
-    case 'A':
-    case 'B':
-        note = (ch - 'A') * 2 + 9;
-        break;
-
-    case 'C':
-    case 'D':
-    case 'E':
-        note = (ch - 'C') * 2;
-        break;
-
-    case 'F':
-    case 'G':
-        note = (ch - 'F') * 2 + 5;
-        break;
-    }
-#endif
-
-#if 0
-    switch (ch)
-    {
-    case 'A':
-        note = 9; break;
-    case 'B':
-        note = 11; break;
-        break;
-    case 'C':
-        note = 0; break;
-    case 'D':
-        note = 2; break;
-    case 'E':
-        note = 4; break;
-    case 'F':
-        note = 5; break;
-    case 'G':
-        note = 7; break;
-    default:
-        note = 0;
-        break;
-    }
-
-#endif
-
-    return note;
-}
-
-
-/* Scan next part of melody until a note or end of melody is found.  */
-static const char *
-squeaker_scan (squeaker_t squeaker, const char *str)
-{
-    while (1)
-    {
-        uint8_t num;
-        char cmd;
-        char modifier;
-        bool have_hash;
-        bool have_num;
-        squeaker_note_t note;
-        
-        /* Play rest at end of melody.  */
-        if (! *str)
-        {
-            squeaker_rest_play (squeaker);
-            return str;
-        }
-
-        cmd = *str++;
-
-        have_hash = *str == '#';
-        if (have_hash)
-            str++;
-
-        modifier = 0;
-        if (*str == '+' || *str == '-')
-            modifier = *str++;
-
-        have_num = 0;
-        num = 0;
-        while (*str >= '0' && *str <= '9')
-        {
-            have_num = 1;
-            num = num * 10 + *str++ - '0';
-        }
-
-        switch (cmd)
-        {
-            /* Repeat sequence from start.  */
-        case ':':
-            str = squeaker->start;
-            continue;
-
-            /* Define start of loop.  */
-        case '<':
-            /* We could implement a small stack to allow nested
-               loops.  */
-            squeaker->loop_start = str;
-            squeaker->loop_count = 0;
-            continue;
-            
-            /* Loop.  */
-        case '>':
-            squeaker->loop_count++;
-            if (!num)
-                num = 2;
-
-            if (squeaker->loop_count < num)
-            {
-                /* Jump to start of loop.  If no start of loop symbol,
-                   jump to start.  */
-                str = squeaker->loop_start;
-                if (!str)
-                    str = squeaker->start;
-            }
-            continue;
-
-            /* Alternate endings.  */
-        case '[':
-            if (squeaker->loop_count == num - 1)
-                continue;
-
-            /* Skip to next alternate ending, the end of loop, or end of
-               melody.  */
-            while (*str && *str != '[' && *str != '>')
-                str++;
-            continue;
-
-            /* Play rest.  */
-        case ' ':
-            squeaker_rest_play (squeaker);
-            return str;
-            break;
-            
-        case '*':
-            if (num)
-                squeaker_note_fraction_set (squeaker, num);
-            continue;
-
-        case '@':
-            if (num)
-                squeaker_speed_set (squeaker, num);
-            continue;
-
-        case 'A':
-        case 'B':
-        case 'C':
-        case 'D':
-        case 'E':
-        case 'F':
-        case 'G':
-            note = squeaker_char_to_note (cmd);
-
-            if (have_hash)
-                note++;
-
-            if (have_num)
-                squeaker->octave = num;
-
-            if (modifier == '+')
-                note += SQUEAKER_SCALE_SIZE;
-
-            if (modifier == '-')
-                note -= SQUEAKER_SCALE_SIZE;
-
-            /* Convert note to MIDI note number.  */
-            note += (squeaker->octave + 1) * SQUEAKER_SCALE_SIZE;
-
-            squeaker_note_play (squeaker, note);
-            return str;
-            break;
-            
-            /* Continue with previous note.  */
-        case '/':
-        default:
-            return str;
-            break;
-        }
-    }
-    return str;
-}
-
-
-void 
-squeaker_play (squeaker_t squeaker, const char *str)
-{
-    squeaker->cur = squeaker->start = str;
-    squeaker->loop_start = 0;
-    squeaker->loop_count = 0;
-    squeaker->octave = SQUEAKER_OCTAVE_DEFAULT;
-    squeaker_note_fraction_set (squeaker, 4);
-}
-
-
-/* Set (base) speed in beats per minute (BPM).  */
-void 
-squeaker_speed_set (squeaker_t squeaker, squeaker_speed_t speed)
-{
-    squeaker->speed = speed;
-    squeaker_ticker_set (squeaker);
-}
-
-
-/* Set volume as percentage of maximum.  */
-void 
-squeaker_volume_set (squeaker_t squeaker, squeaker_volume_t volume)
-{
-    squeaker->volume = volume;
-}
-
-
-int8_t
-squeaker_update (squeaker_t squeaker)
-{
-    /* Rather than a 16 bit ticker it is faster to use
-       an 8-bit prescaler and an 8-bit ticker.  */
-    
-    squeaker->prescaler++;
-    if (! squeaker->prescaler)
-    {
-        if (TICKER_UPDATE (&squeaker->ticker))
-        {
-            if (squeaker->cur)
-                squeaker->cur = squeaker_scan (squeaker, squeaker->cur);
-        }
-
-        /* We could halve the note duty after some interval to
-           simulate note decay.  The decay interval could be related
-           to the desired sustain.  This approach is a bit brutal
-           especially when the duty is small.  */
-
-        if (squeaker->note_holdoff)
-            squeaker->note_holdoff--;
-    }
-
-    if (++squeaker->note_clock >= squeaker->note_period)
-        squeaker->note_clock = 0;
-    
-    return squeaker->note_clock < squeaker->note_duty 
-        && ! squeaker->note_holdoff;
-}
-
-
-squeaker_t
-squeaker_init (squeaker_obj_t *squeaker, 
-               uint16_t poll_rate,
-               squeaker_scale_t *scale_table)
-{
-    squeaker->poll_rate = poll_rate;
-    squeaker->scale_table = scale_table;
-    squeaker->note_period = 0;
-    squeaker->note_duty = 0;
-    squeaker->volume = 127;
-    squeaker->prescaler = 0;
-    squeaker->holdoff = squeaker->poll_rate 
-        / (uint16_t)(SQUEAKER_PRESCALER / SQUEAKER_HOLDOFF_TIME);
-
-    squeaker_play (squeaker, 0);
-    squeaker_speed_set (squeaker, SQUEAKER_SPEED_DEFAULT);
-    return squeaker;
-}
diff --git a/extra/squeaker.h b/extra/squeaker.h
deleted file mode 100644
index bcb75a1..0000000
--- a/extra/squeaker.h
+++ /dev/null
@@ -1,123 +0,0 @@
-/** @file   squeaker.h
-    @author M. P. Hayes, UCECE
-    @date   14 April 2007
-    @brief  Play simple tunes with PWM.
-*/
-#ifndef SQUEAKER_H
-#define SQUEAKER_H
-
-#include "system.h"
-#include "ticker.h"
-
-typedef uint8_t squeaker_speed_t;
-typedef uint8_t squeaker_scale_t;
-typedef uint8_t squeaker_note_t;
-typedef uint8_t squeaker_duration_t;
-typedef uint8_t squeaker_period_t;
-typedef uint8_t squeaker_volume_t;
-
-
-enum {SQUEAKER_OCTAVE_DEFAULT = 4};
-enum {SQUEAKER_SPEED_DEFAULT = 200};
-
-
-/* Could calculate scale divisors at run time.  2^(1/2) is approx
-   1.0594631.  A reasonable rational approximation is 267/252 =
-   1.0595238.  Let's save memory and provide a macro to compute the
-   divisors.  */
-
-#define SQUEAKER_DIVISOR(POLL_RATE, FREQ) (POLL_RATE / FREQ + 0.5)
-
-
-#if 0
-enum {SQUEAKER_NOTE_MIN = 60};
-/* Define divisors for chromatic scale C4 -> C5.  For better accuracy
-   this should be defined for the lowest frequency scale, however,
-   this may need 16 bits per note.  */
-#define SQUEAKER_SCALE_TABLE(POLL_RATE) \
-   {SQUEAKER_DIVISOR (POLL_RATE, 261.6256), \
-    SQUEAKER_DIVISOR (POLL_RATE, 277.1826), \
-    SQUEAKER_DIVISOR (POLL_RATE, 293.6648), \
-    SQUEAKER_DIVISOR (POLL_RATE, 311.1270), \
-    SQUEAKER_DIVISOR (POLL_RATE, 329.6276), \
-    SQUEAKER_DIVISOR (POLL_RATE, 349.2282), \
-    SQUEAKER_DIVISOR (POLL_RATE, 369.9944), \
-    SQUEAKER_DIVISOR (POLL_RATE, 391.9954), \
-    SQUEAKER_DIVISOR (POLL_RATE, 415.3047), \
-    SQUEAKER_DIVISOR (POLL_RATE, 440.0000), \
-    SQUEAKER_DIVISOR (POLL_RATE, 466.1638), \
-    SQUEAKER_DIVISOR (POLL_RATE, 493.8833)}
-#else
-enum {SQUEAKER_NOTE_MIN = 40};
-/* Define divisors for chromatic scale E2 -> D#3.  For better accuracy
-   this should be defined for the lowest frequency scale, however,
-   this may need 16 bits per note.  */
-#define SQUEAKER_SCALE_TABLE(POLL_RATE) \
-   {SQUEAKER_DIVISOR (POLL_RATE, 82.41), \
-    SQUEAKER_DIVISOR (POLL_RATE, 87.31), \
-    SQUEAKER_DIVISOR (POLL_RATE, 92.50), \
-    SQUEAKER_DIVISOR (POLL_RATE, 98.00), \
-    SQUEAKER_DIVISOR (POLL_RATE, 103.83), \
-    SQUEAKER_DIVISOR (POLL_RATE, 110.0), \
-    SQUEAKER_DIVISOR (POLL_RATE, 116.54), \
-    SQUEAKER_DIVISOR (POLL_RATE, 123.47), \
-    SQUEAKER_DIVISOR (POLL_RATE, 130.81), \
-    SQUEAKER_DIVISOR (POLL_RATE, 138.59), \
-    SQUEAKER_DIVISOR (POLL_RATE, 146.83), \
-    SQUEAKER_DIVISOR (POLL_RATE, 155.56)}
-#endif
-
-typedef struct
-{
-    uint8_t note_clock;
-    uint8_t note_period;
-    uint8_t note_duty;
-    uint8_t note_holdoff;
-    /* Pointer to start of string.  */
-    const char *start;
-    /* Pointer to current position in string.  */    
-    const char *cur;
-    uint8_t holdoff;
-    uint16_t poll_rate;
-    const char *loop_start;
-    int8_t loop_count;
-    uint8_t prescaler;
-    uint8_t note_fraction;
-    squeaker_speed_t speed;
-    squeaker_volume_t volume;
-    ticker8_t ticker;
-    squeaker_scale_t *scale_table;
-    uint8_t octave;
-} squeaker_private_t;
-
-
-typedef squeaker_private_t squeaker_obj_t;
-typedef squeaker_obj_t *squeaker_t;
-
-
-/* The scale table is usually defined with:
-
- static squeaker_scale_t scale_table[] = SQUEAKER_SCALE_TABLE (LOOP_POLL_RATE);
-*/
-
-
-extern squeaker_t
-squeaker_init (squeaker_obj_t *dev, 
-               uint16_t poll_rate,
-               squeaker_scale_t *scale_table);
-
-extern void 
-squeaker_play (squeaker_t squeaker, const char *str);
-
-extern int8_t 
-squeaker_update (squeaker_t squeaker);
-
-/* Set (base) speed in beats per minute (BPM).  */
-extern void 
-squeaker_speed_set (squeaker_t squeaker, squeaker_speed_t speed);
-
-/* Set volume as percentage of maximum.  */
-extern void 
-squeaker_volume_set (squeaker_t squeaker, squeaker_volume_t volume);
-
-#endif