diff --git a/dmx8chan.c b/dmx8chan.c
index 26bc894..56eeea8 100644
--- a/dmx8chan.c
+++ b/dmx8chan.c
@@ -51,44 +51,28 @@ ISR(SIG_OVERFLOW1)
 /*
  * Timer 1 Compare Match (every 40us)
  * - schedule next compare match in 40us
+ * - set PWM Outputs (PORTB)
  */
 ISR(SIG_OUTPUT_COMPARE1A)
 {
 	OCR1A = pwm_load;
 	pwm_load += TIMER1_STEP;
 
-	uint8_t *tmp = chan;
-	uint8_t out = PORTB;
-
 	cnt--;
 
+	uint8_t out = PORTB;
 	if (cnt == 0xFF)
 		out = 0x00;
 
-	if (*tmp++ >= cnt)
-		out |= (1<<PORTB0);
+	uint8_t i, shift = 1;
+	uint8_t *tmp = chan;
 
-	if (*tmp++ >= cnt)
-		out |= (1<<PORTB1);
-
-	if (*tmp++ >= cnt)
-		out |= (1<<PORTB2);
-
-	if (*tmp++ >= cnt)
-		out |= (1<<PORTB3);
-
-	if (*tmp++ >= cnt)
-		out |= (1<<PORTB4);
-
-	if (*tmp++ >= cnt)
-		out |= (1<<PORTB5);
-
-	if (*tmp++ >= cnt)
-		out |= (1<<PORTB6);
-
-	if (*tmp++ >= cnt)
-		out |= (1<<PORTB7);
+	for (i = 0; i < 8; i++) {
+		if (*tmp++ >= cnt)
+			out |= shift;
 
+		shift <<= 1;
+	}
 	PORTB = out;
 }