Hello , Please can anyone help me to modify this basic program ! at the present time, the frequence portB.5 output is ~30 Hz How I can modify for a output = ~ 1000 Hz Pic = 16F84 Xt = 4.00 MHz ' Set TMR0 to interrupt every 16,384 milliseconds OPTION_REG = $d5 ' Set TMR0 configuration INTCON = $a0 ' Enable TMR0 interrupts On interrupt Goto INTCARRE MainLoop: ' ' Goto MainLoop Disable ' Disable interrupt during interrupt handler INTCARRE: TOGGLE PORTB.5 ' change state of pin portB.5 INTCON.2 = 0 ' Reset timer interrupt flag resume Weslay@Aol.com -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads