diff --git a/module01/ex01/main.c b/module01/ex01/main.c
index 969e762..821f707 100644
--- a/module01/ex01/main.c
+++ b/module01/ex01/main.c
@@ -71,7 +71,7 @@ int main() {
 
 	TCCR1A |= (1 << COM1A0);		// 14.3.1 : set Compare Output with COM1A0, it toggles OC1A on compare match (Table 16-1), OC1A is alternate function for PORTB1 (Table 14-3)
 
-	OCR1A = TIME_MS(PERIOD);		// Table 16-4 : set CTC compare value, the counter is cleared to zero when the counter value (TCNT1) matches the OCR1A register
+	OCR1A = TIME_MS(PERIOD);		// Table 16-4 : set CTC compare value on channel A, the counter is cleared to zero when the counter value (TCNT1) matches the OCR1A register
 
 	TCCR1B |= (PRESCALE_SET(PRESCALE_VALUE));
 
diff --git a/module01/ex02/main.c b/module01/ex02/main.c
index 50cf69d..e6c58c7 100644
--- a/module01/ex02/main.c
+++ b/module01/ex02/main.c
@@ -77,7 +77,7 @@ int main() {
 
     ICR1 = TIME_MS(PERIOD);							// Table 16-4 : set the period (compare TOP value)
     
-    OCR1A = TIME_MS(PERCENT(DUTY_CYCLE, PERIOD));	// 16.9.3 : set the duty cycle to DUTY_CYCLE% of the time -> OC1A (alternate function of PORTB1, aka LED2) is cleared when TCNT1 (the counter value) equals OCR1A
+    OCR1A = TIME_MS(PERCENT(DUTY_CYCLE, PERIOD));	// 16.9.3 : set the duty cycle to DUTY_CYCLE% of the time on channel A -> OC1A (alternate function of PORTB1, aka LED2) is cleared when TCNT1 (the counter value) equals OCR1A
 
     TCCR1B |= (PRESCALE_SET(PRESCALE_VALUE));						// start the timer with the prescaler
 
diff --git a/module01/ex03/main.c b/module01/ex03/main.c
index 042de93..079bba8 100644
--- a/module01/ex03/main.c
+++ b/module01/ex03/main.c
@@ -123,7 +123,7 @@ int main() {
 
     ICR1 = TIME_MS(PERIOD);							// Table 16-4 : set the period (compare TOP value)
     
-    OCR1A = TIME_MS(PERCENT(DUTY_CYCLE, PERIOD));	// 16.9.3 : set the duty cycle to DUTY_CYCLE% of the time -> OC1A (alternate function of PORTB1, aka LED2) is cleared when TCNT1 (the counter value) equals OCR1A
+    OCR1A = TIME_MS(PERCENT(DUTY_CYCLE, PERIOD));	// 16.9.3 : set the duty cycle to DUTY_CYCLE% of the time in channel A -> OC1A (alternate function of PORTB1, aka LED2) is cleared when TCNT1 (the counter value) equals OCR1A
 
     TCCR1B |= (PRESCALE_SET(PRESCALE_VALUE));						// start the timer with the prescaler
 
diff --git a/module02/ex01/main.c b/module02/ex01/main.c
index 7c9cbae..9ec71cb 100644
--- a/module02/ex01/main.c
+++ b/module02/ex01/main.c
@@ -132,6 +132,7 @@ void uart_printstr(const char* str) {
 }
 
 // print hello world, on serial port, every 2 seconds, with empty infinite loop
+// `screen /dev/ttyUSB0 115200`
 int main() {
 	uart_init();
 
@@ -141,7 +142,7 @@ int main() {
 	TIMSK1 |= (1 << OCIE1A);						// Enable CTC interrupt
 	sei();											// Enable global interrupts
 
-	OCR1A = TIME_MS(PERIOD);						// Table 16-4 : set CTC compare value, the counter is cleared to zero when the counter value (TCNT1) matches the OCR1A register
+	OCR1A = TIME_MS(PERIOD);						// Table 16-4 : set CTC compare value on channel A, the counter is cleared to zero when the counter value (TCNT1) matches the OCR1A register
 
 	TCCR1B |= (PRESCALE_SET(PRESCALE_VALUE));		// 16.4 : set timer according to prescale value, in register TCCR1B, table 16-5 : prescale sets