> movlw   b'00000000'
> option

When TMR0 is assigned to the prescaler the minimum scale ratio is 1:2,
that is why you are getting 2 'ticks' per tmr0 increment. The ratio is
set 1:1 when the prescaler is assigned to the WDT.

--
Best regards

Tony

Multimedia 16F84 Beginners PIC Tools.
** NEW PicNPro Programmer and Port Interface **

http://www.picnpoke.com
Email picnpoke@cdi.com.au