diff --git a/avr/devices/c01/main/main.asm b/avr/devices/c01/main/main.asm
index 58b5e2f..e902a03 100644
--- a/avr/devices/c01/main/main.asm
+++ b/avr/devices/c01/main/main.asm
@@ -119,7 +119,7 @@
 ; Reset and interrupt vectors
   rjmp BOOTLOADER_ADDR          ;  1: Reset vector   RESET
 ;  rjmp NetUart_AttnChangeIsr    ;  2: INT0           External Interrupt Request 0
-  rjmp UART_BitBang_PcintIsr
+  rjmp UART_BitBang_PcintIsr    ;  2: INT0           External Interrupt Request 0
   reti                          ;  3: INT1           External Interrupt Request 1
   reti                          ;  4: TIMER1_CAPT    Timer/Counter1 Capture Event
   reti                          ;  5: TIMER1_COMPA   Timer/Counter1 Compare Match A