diff --git a/apps/beep1/Makefile b/apps/beep1/Makefile
index d7d8c4a..a47830b 100644
--- a/apps/beep1/Makefile
+++ b/apps/beep1/Makefile
@@ -5,7 +5,7 @@
 
 # Definitions.
 CC = avr-gcc
-CFLAGS = -mmcu=atmega32u2 -Os -Wall -Wstrict-prototypes -Wextra -g -I../../drivers/avr -I../../drivers -I../../utils
+CFLAGS = -mmcu=atmega32u2 -Os -Wall -Wstrict-prototypes -Wextra -g -I../../drivers/avr -I../../utils
 OBJCOPY = avr-objcopy
 SIZE = avr-size
 DEL = rm
@@ -16,7 +16,7 @@ all: beep1.out
 
 
 # Compile: create object files from C source files.
-beep1.o: beep1.c ../../drivers/avr/delay.h ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/button.h ../../drivers/led.h ../../utils/pacer.h
+beep1.o: beep1.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../utils/pacer.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
 pio.o: ../../drivers/avr/pio.c ../../drivers/avr/pio.h ../../drivers/avr/system.h
@@ -28,12 +28,6 @@ system.o: ../../drivers/avr/system.c ../../drivers/avr/system.h
 timer.o: ../../drivers/avr/timer.c ../../drivers/avr/system.h ../../drivers/avr/timer.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
-button.o: ../../drivers/button.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/button.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 $@
-
 pacer.o: ../../utils/pacer.c ../../drivers/avr/system.h ../../drivers/avr/timer.h ../../utils/pacer.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
@@ -41,7 +35,7 @@ pacer.o: ../../utils/pacer.c ../../drivers/avr/system.h ../../drivers/avr/timer.
 
 
 # Link: create output file (executable) from object files.
-beep1.out: beep1.o pio.o system.o timer.o button.o led.o pacer.o
+beep1.out: beep1.o pio.o system.o timer.o pacer.o
 	$(CC) $(CFLAGS) $^ -o $@ -lm
 	$(SIZE) $@
 
diff --git a/apps/beep1/doc/Makefile b/apps/beep1/doc/Makefile
index 2fd302c..5fea900 100644
--- a/apps/beep1/doc/Makefile
+++ b/apps/beep1/doc/Makefile
@@ -1,7 +1,7 @@
 # File:   Makefile
 # Author: M. P. Hayes, UCECE
 # Date:   11 Sep 2010
-# Descr:  Makefile for squeak1 docs
+# Descr:  Makefile for beep1 docs
 
 # The scripts used to make the graphs require the program dot; this
 # is part of the graphviz package.
diff --git a/apps/beep2/Makefile b/apps/beep2/Makefile
index 879c10e..d30e6db 100644
--- a/apps/beep2/Makefile
+++ b/apps/beep2/Makefile
@@ -16,7 +16,7 @@ all: beep2.out
 
 
 # Compile: create object files from C source files.
-beep2.o: beep2.c ../../drivers/avr/delay.h ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/button.h ../../drivers/led.h ../../utils/pacer.h
+beep2.o: beep2.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/button.h ../../utils/pacer.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
 pio.o: ../../drivers/avr/pio.c ../../drivers/avr/pio.h ../../drivers/avr/system.h
@@ -31,9 +31,6 @@ timer.o: ../../drivers/avr/timer.c ../../drivers/avr/system.h ../../drivers/avr/
 button.o: ../../drivers/button.c ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/button.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 $@
-
 pacer.o: ../../utils/pacer.c ../../drivers/avr/system.h ../../drivers/avr/timer.h ../../utils/pacer.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
@@ -41,7 +38,7 @@ pacer.o: ../../utils/pacer.c ../../drivers/avr/system.h ../../drivers/avr/timer.
 
 
 # Link: create output file (executable) from object files.
-beep2.out: beep2.o pio.o system.o timer.o button.o led.o pacer.o
+beep2.out: beep2.o pio.o system.o timer.o button.o pacer.o
 	$(CC) $(CFLAGS) $^ -o $@ -lm
 	$(SIZE) $@
 
diff --git a/apps/beep2/doc/Makefile b/apps/beep2/doc/Makefile
index 2fd302c..211e384 100644
--- a/apps/beep2/doc/Makefile
+++ b/apps/beep2/doc/Makefile
@@ -1,7 +1,7 @@
 # File:   Makefile
 # Author: M. P. Hayes, UCECE
 # Date:   11 Sep 2010
-# Descr:  Makefile for squeak1 docs
+# Descr:  Makefile for beep2 docs
 
 # The scripts used to make the graphs require the program dot; this
 # is part of the graphviz package.
diff --git a/apps/ir_spam1/doc/Makefile b/apps/ir_spam1/doc/Makefile
index 00afecd..a3ec8fd 100644
--- a/apps/ir_spam1/doc/Makefile
+++ b/apps/ir_spam1/doc/Makefile
@@ -1,7 +1,7 @@
 # File:   Makefile
 # Author: M. P. Hayes, UCECE
 # Date:   11 Sep 2010
-# Descr:  Makefile for ir_uart_test1 docs
+# Descr:  Makefile for ir_spam1 docs
 
 # The scripts used to make the graphs require the program dot; this
 # is part of the graphviz package.
diff --git a/apps/ir_uart_demo1/doc/Makefile b/apps/ir_uart_demo1/doc/Makefile
index 195c459..d77c744 100644
--- a/apps/ir_uart_demo1/doc/Makefile
+++ b/apps/ir_uart_demo1/doc/Makefile
@@ -1,7 +1,7 @@
 # File:   Makefile
 # Author: M. P. Hayes, UCECE
 # Date:   11 Sep 2010
-# Descr:  Makefile for ir_uart_test3 docs
+# Descr:  Makefile for ir_uart_demo1 docs
 
 # The scripts used to make the graphs require the program dot; this
 # is part of the graphviz package.
diff --git a/apps/ir_uart_test1/Makefile b/apps/ir_uart_test1/Makefile
index 1e977ce..3701393 100644
--- a/apps/ir_uart_test1/Makefile
+++ b/apps/ir_uart_test1/Makefile
@@ -19,7 +19,7 @@ all: ir_uart_test1.out
 ir_uart_test1.o: ir_uart_test1.c ../../drivers/avr/ir_uart.h ../../drivers/avr/system.h ../../drivers/display.h ../../drivers/navswitch.h ../../fonts/font5x7_1.h ../../utils/font.h ../../utils/pacer.h ../../utils/tinygl.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
-ir_uart.o: ../../drivers/avr/ir_uart.c ../../drivers/avr/ir_uart.h ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer0.h ../../drivers/avr/usart1.h
+ir_uart.o: ../../drivers/avr/ir_uart.c ../../drivers/avr/delay.h ../../drivers/avr/ir_uart.h ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer0.h ../../drivers/avr/usart1.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
 pio.o: ../../drivers/avr/pio.c ../../drivers/avr/pio.h ../../drivers/avr/system.h
diff --git a/apps/ir_uart_test2/Makefile b/apps/ir_uart_test2/Makefile
index e34b37a..1ea65d6 100644
--- a/apps/ir_uart_test2/Makefile
+++ b/apps/ir_uart_test2/Makefile
@@ -19,7 +19,7 @@ all: ir_uart_test2.out
 ir_uart_test2.o: ir_uart_test2.c ../../drivers/avr/ir_uart.h ../../drivers/avr/system.h ../../drivers/display.h ../../drivers/navswitch.h ../../fonts/font5x7_1.h ../../utils/font.h ../../utils/pacer.h ../../utils/tinygl.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
-ir_uart.o: ../../drivers/avr/ir_uart.c ../../drivers/avr/ir_uart.h ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer0.h ../../drivers/avr/usart1.h
+ir_uart.o: ../../drivers/avr/ir_uart.c ../../drivers/avr/delay.h ../../drivers/avr/ir_uart.h ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer0.h ../../drivers/avr/usart1.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
 pio.o: ../../drivers/avr/pio.c ../../drivers/avr/pio.h ../../drivers/avr/system.h
diff --git a/apps/ir_uart_test3/Makefile b/apps/ir_uart_test3/Makefile
index 3d77367..90b2925 100644
--- a/apps/ir_uart_test3/Makefile
+++ b/apps/ir_uart_test3/Makefile
@@ -19,7 +19,7 @@ all: ir_uart_test3.out
 ir_uart_test3.o: ir_uart_test3.c ../../drivers/avr/ir_uart.h ../../drivers/avr/system.h ../../drivers/display.h ../../drivers/navswitch.h ../../fonts/font3x5_1.h ../../utils/font.h ../../utils/pacer.h ../../utils/tinygl.h ../../utils/uint8toa.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
-ir_uart.o: ../../drivers/avr/ir_uart.c ../../drivers/avr/ir_uart.h ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer0.h ../../drivers/avr/usart1.h
+ir_uart.o: ../../drivers/avr/ir_uart.c ../../drivers/avr/delay.h ../../drivers/avr/ir_uart.h ../../drivers/avr/pio.h ../../drivers/avr/system.h ../../drivers/avr/timer0.h ../../drivers/avr/usart1.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
 pio.o: ../../drivers/avr/pio.c ../../drivers/avr/pio.h ../../drivers/avr/system.h
diff --git a/apps/ir_uart_test3/doc/callgraph.d b/apps/ir_uart_test3/doc/callgraph.d
index 2fcb1fe..b1943dd 100644
--- a/apps/ir_uart_test3/doc/callgraph.d
+++ b/apps/ir_uart_test3/doc/callgraph.d
@@ -116,7 +116,11 @@ usart1_write_ready_p@usart1.c:
 
 usart1_putc@usart1.c: usart1_write_ready_p
 
-ir_uart_putc@ir_uart.c: usart1_putc
+usart1_write_finished_p@usart1.c: 
 
-main@ir_uart_test3.c: system_init tinygl_init tinygl_font_set tinygl_text_speed_set tinygl_text_mode_set tinygl_text_dir_set navswitch_init ir_uart_init pacer_init show_byte pacer_wait tinygl_update ir_uart_read_ready_p ir_uart_getc show_byte navswitch_update navswitch_push_event_p ir_uart_putc ir_uart_getc navswitch_push_event_p ir_uart_putc ir_uart_getc
+ir_uart_write_finished_p@ir_uart.c: usart1_write_finished_p
+
+ir_uart_putc@ir_uart.c: usart1_putc ir_uart_write_finished_p _delay_loop_1 ir_uart_read_ready_p ir_uart_getc
+
+main@ir_uart_test3.c: system_init tinygl_init tinygl_font_set tinygl_text_speed_set tinygl_text_mode_set tinygl_text_dir_set navswitch_init ir_uart_init pacer_init show_byte pacer_wait tinygl_update ir_uart_read_ready_p ir_uart_getc show_byte navswitch_update navswitch_push_event_p ir_uart_putc navswitch_push_event_p ir_uart_putc
 
diff --git a/apps/ir_uart_test3/doc/files.d b/apps/ir_uart_test3/doc/files.d
index aeb929e..acde90f 100644
--- a/apps/ir_uart_test3/doc/files.d
+++ b/apps/ir_uart_test3/doc/files.d
@@ -26,7 +26,9 @@
 
 ../../drivers/avr/pio.h: 
 
-../../drivers/avr/ir_uart.c: ../../drivers/avr/ir_uart.h ../../drivers/avr/usart1.h ../../drivers/avr/timer0.h ../../drivers/avr/pio.h
+../../drivers/avr/delay.h: 
+
+../../drivers/avr/ir_uart.c: ../../drivers/avr/ir_uart.h ../../drivers/avr/usart1.h ../../drivers/avr/timer0.h ../../drivers/avr/pio.h ../../drivers/avr/delay.h
 
 ../../drivers/avr/ir_uart.o: ../../drivers/avr/ir_uart.c
 
@@ -80,8 +82,6 @@ ir_uart_test3.o: ir_uart_test3.c
 
 ../../drivers/avr/prescale.o: ../../drivers/avr/prescale.c
 
-../../drivers/avr/delay.h: 
-
 ../../drivers/navswitch.c: ../../drivers/navswitch.h ../../drivers/avr/delay.h ../../drivers/avr/pio.h
 
 ../../drivers/navswitch.o: ../../drivers/navswitch.c
diff --git a/apps/ir_uart_test4/doc/Makefile b/apps/ir_uart_test4/doc/Makefile
index 195c459..87c8f09 100644
--- a/apps/ir_uart_test4/doc/Makefile
+++ b/apps/ir_uart_test4/doc/Makefile
@@ -1,7 +1,7 @@
 # File:   Makefile
 # Author: M. P. Hayes, UCECE
 # Date:   11 Sep 2010
-# Descr:  Makefile for ir_uart_test3 docs
+# Descr:  Makefile for ir_uart_test4 docs
 
 # The scripts used to make the graphs require the program dot; this
 # is part of the graphviz package.
diff --git a/apps/jukebox1/doc/Makefile b/apps/jukebox1/doc/Makefile
index eb29a6d..dc6e144 100644
--- a/apps/jukebox1/doc/Makefile
+++ b/apps/jukebox1/doc/Makefile
@@ -1,7 +1,7 @@
 # File:   Makefile
 # Author: M. P. Hayes, UCECE
 # Date:   11 Sep 2010
-# Descr:  Makefile for squeak4 docs
+# Descr:  Makefile for jukebox1 docs
 
 # The scripts used to make the graphs require the program dot; this
 # is part of the graphviz package.
diff --git a/apps/ledpwm1/doc/Makefile b/apps/ledpwm1/doc/Makefile
index c93d18c..cbae4f8 100644
--- a/apps/ledpwm1/doc/Makefile
+++ b/apps/ledpwm1/doc/Makefile
@@ -1,7 +1,7 @@
 # File:   Makefile
 # Author: M. P. Hayes, UCECE
 # Date:   11 Sep 2010
-# Descr:  Makefile for led5 docs
+# Descr:  Makefile for ledpwm1 docs
 
 # The scripts used to make the graphs require the program dot; this
 # is part of the graphviz package.
diff --git a/apps/race1/doc/Makefile b/apps/race1/doc/Makefile
index 195c459..83c8618 100644
--- a/apps/race1/doc/Makefile
+++ b/apps/race1/doc/Makefile
@@ -1,7 +1,7 @@
 # File:   Makefile
 # Author: M. P. Hayes, UCECE
 # Date:   11 Sep 2010
-# Descr:  Makefile for ir_uart_test3 docs
+# Descr:  Makefile for race1 docs
 
 # The scripts used to make the graphs require the program dot; this
 # is part of the graphviz package.
diff --git a/apps/random1/doc/Makefile b/apps/random1/doc/Makefile
index c93d18c..a37659a 100644
--- a/apps/random1/doc/Makefile
+++ b/apps/random1/doc/Makefile
@@ -1,7 +1,7 @@
 # File:   Makefile
 # Author: M. P. Hayes, UCECE
 # Date:   11 Sep 2010
-# Descr:  Makefile for led5 docs
+# Descr:  Makefile for random1 docs
 
 # The scripts used to make the graphs require the program dot; this
 # is part of the graphviz package.
diff --git a/apps/random2/doc/Makefile b/apps/random2/doc/Makefile
index c93d18c..5ac4e49 100644
--- a/apps/random2/doc/Makefile
+++ b/apps/random2/doc/Makefile
@@ -1,7 +1,7 @@
 # File:   Makefile
 # Author: M. P. Hayes, UCECE
 # Date:   11 Sep 2010
-# Descr:  Makefile for led5 docs
+# Descr:  Makefile for random2 docs
 
 # The scripts used to make the graphs require the program dot; this
 # is part of the graphviz package.
diff --git a/apps/snake1/Makefile b/apps/snake1/Makefile
index 8aed64a..5f9c37b 100644
--- a/apps/snake1/Makefile
+++ b/apps/snake1/Makefile
@@ -5,7 +5,7 @@
 
 # Definitions.
 CC = avr-gcc
-CFLAGS = -mmcu=atmega32u2 -Os -Wall -Wstrict-prototypes -Wextra -g -I../../drivers/avr -I../../fonts -I../../drivers -I../../utils
+CFLAGS = -mmcu=atmega32u2 -Os -Wall -Wstrict-prototypes -Wextra -g -I../../drivers/avr -I../../drivers -I../../utils
 OBJCOPY = avr-objcopy
 SIZE = avr-size
 DEL = rm
@@ -16,7 +16,7 @@ all: snake1.out
 
 
 # Compile: create object files from C source files.
-snake1.o: snake1.c ../../drivers/avr/system.h ../../drivers/display.h ../../drivers/navswitch.h ../../fonts/font5x7_1.h ../../utils/font.h ../../utils/pacer.h ../../utils/tinygl.h
+snake1.o: snake1.c ../../drivers/avr/system.h ../../drivers/display.h ../../drivers/navswitch.h ../../utils/font.h ../../utils/pacer.h ../../utils/tinygl.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
 pio.o: ../../drivers/avr/pio.c ../../drivers/avr/pio.h ../../drivers/avr/system.h
diff --git a/apps/snake1/Makefile.test b/apps/snake1/Makefile.test
index 44cab5b..a50e6e4 100644
--- a/apps/snake1/Makefile.test
+++ b/apps/snake1/Makefile.test
@@ -4,7 +4,7 @@
 # Descr:  Makefile for snake1
 
 CC = gcc
-CFLAGS = -Wall -Wstrict-prototypes -Wextra -g -I../../drivers/test -I../../drivers -I../../fonts -I../../utils
+CFLAGS = -Wall -Wstrict-prototypes -Wextra -g -I../../drivers/test -I../../drivers -I../../utils
 
 DEL = rm
 
@@ -14,7 +14,7 @@ all: snake1
 
 
 # Compile: create object files from C source files.
-snake1-test.o: snake1.c ../../drivers/display.h ../../drivers/navswitch.h ../../drivers/test/system.h ../../fonts/font5x7_1.h ../../utils/font.h ../../utils/pacer.h ../../utils/tinygl.h
+snake1-test.o: snake1.c ../../drivers/display.h ../../drivers/navswitch.h ../../drivers/test/system.h ../../utils/font.h ../../utils/pacer.h ../../utils/tinygl.h
 	$(CC) -c $(CFLAGS) $< -o $@
 
 display-test.o: ../../drivers/display.c ../../drivers/display.h ../../drivers/ledmat.h ../../drivers/test/system.h
diff --git a/apps/stars1/doc/Makefile b/apps/stars1/doc/Makefile
index c93d18c..31861ff 100644
--- a/apps/stars1/doc/Makefile
+++ b/apps/stars1/doc/Makefile
@@ -1,7 +1,7 @@
 # File:   Makefile
 # Author: M. P. Hayes, UCECE
 # Date:   11 Sep 2010
-# Descr:  Makefile for led5 docs
+# Descr:  Makefile for stars1 docs
 
 # The scripts used to make the graphs require the program dot; this
 # is part of the graphviz package.
diff --git a/apps/stars2/doc/Makefile b/apps/stars2/doc/Makefile
index c93d18c..f13dba5 100644
--- a/apps/stars2/doc/Makefile
+++ b/apps/stars2/doc/Makefile
@@ -1,7 +1,7 @@
 # File:   Makefile
 # Author: M. P. Hayes, UCECE
 # Date:   11 Sep 2010
-# Descr:  Makefile for led5 docs
+# Descr:  Makefile for stars2 docs
 
 # The scripts used to make the graphs require the program dot; this
 # is part of the graphviz package.
diff --git a/drivers/avr/ir_uart.c b/drivers/avr/ir_uart.c
index 361f47f..c2699c8 100644
--- a/drivers/avr/ir_uart.c
+++ b/drivers/avr/ir_uart.c
@@ -7,6 +7,7 @@
 #include "usart1.h"
 #include "timer0.h"
 #include "pio.h"
+#include "delay.h"
 
 
 /* Return non-zero if there is a character ready to be read.  */
@@ -51,8 +52,25 @@ ir_uart_putc (char ch)
 
     /* Gobble echoed character.  The echoing is due to an electrical
        common-path interference problem caused by a poor PCB layout of the
-       track powering the IR receiver.  */
-    ir_uart_getc ();
+       track powering the IR receiver.  Unfortunately, it does not always
+       occur with some combination of UCFK4 boards and laptops.  Perhaps
+       some laptops are more miserly with their current allocation and
+       some IR LEDs do not draw as much current?  So as a workaround
+       we need to wait until the transmission has finished and then check
+       if something was immediately received. 
+
+       Having said all this, it is possible to get an optical reflection
+       of the transmitted signal.  The following code should handle this 
+       as well.  */
+
+    while (! ir_uart_write_finished_p ())
+        continue;
+
+    /* Play safe and wait for receive complete flag to be set.  */
+    DELAY_US (1);
+    
+    if (ir_uart_read_ready_p ())
+        ir_uart_getc ();
 
     return 1;
 }
diff --git a/drivers/avr/system.h b/drivers/avr/system.h
index 670542e..702b95b 100644
--- a/drivers/avr/system.h
+++ b/drivers/avr/system.h
@@ -8,8 +8,7 @@
 
 /* Data typedefs.  */
 #include <stdint.h>
-
-typedef uint8_t bool;
+#include <stdbool.h>
 
 
 /** Useful macros.  */