> > > org 0 org 0 means that the code you are writing starts at location 0. This means that: nop ^ is at location 0 clrf PORTB ^ is at location 1 bsf STATUS, RP0 ^ is at location 2 movlw 0x070 ^ is at location 3 movwf TRISB ^ is at location 4 bcf STATUS, RP0 et cetera. movlw 0x088 > movwf INTCON > movlw 0x00C > movwf PORTB > > movfw PORTB > movwf pins > > goto mainline > > > org 4 And here you state that the following code should be at location 4. Unfortunately, you already have code at location 4, so the assembler gets a bit confused... Int > movwf _w ; Save Status register prior to ^ this would be put at location 4, but there is already something there... Interrupt Handler Greetings, Maarten Hofman. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist