On 4/21/07, Jinx wrote: > Also, are you using more than one IRQ source ? The comments > and instructions seem to disagree Yes, I only use Timer1 as IRQ-source. The reason the INTF-line was there is because I borrowed it from an ISR from my book (that had an example using Timer1, as well as another IRQ-source). I removed the line and set PEIE in INTCON as Gerhard suggested. Taking your tip about setting consequent bits, I changed the LED-code into this: once_a_sec bcf PIR1, TMR1IF ; Reset interrupt flag xorwf GOING, w btfsc STATUS, Z goto setit bcf PORTA, GREEN_LED goto dontsetit setit bsf PORTA, GREEN_LED dontsetit comf GOING, f return But still, no activity on the LED. The bad thing is I don't own a scope so I cannot even verify that the internal 32kHz-oscillator is running at all. -- - Rikard - http://bos.hack.org/cv/ -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist