Thanks for your interest.

This is what I have done.. So I want to make serial connection

Now i reduced my code.. Now it's working... but if I use PAUSE 1000 without for.. next, it interrupts USB connection.. But leds blinking right time... I will try now serial connection again..

Another question : For what do I need DEFINE RESET_ORG 800h and DEFINE INTERRUPT_ORG 808h ?

define OSC 48
DEFINE LOADER_USED 1
DEFINE RESET_ORG 800h
DEFINE INTERRUPT_ORG 808h
I VAR word
LOW PORTB.0
HIGH PORTB.1
USBINIT

dongu:
FOR I=1 TO 1000
usbservice
pause 1
NEXT I
toggle portb.0
toggle portb.1
goto dongu