Reginald Neale wrote: [snip] > Why can't I tweak the internal oscillator on a 12C671/JW part? I'm using > the standard header file with MPLAB and a PicStart Plus. My code is: > > org 0x00 > movlw 0xXX > movwf OSCCAL > > But no matter what I put in for XX, the osc freq doesn't change. I must be > overlooking something pretty basic. > Reg Neale Reg - - I don't program the 12C671, but the chips that I do program require that the OSCCAL value be placed at the top location in memory. ORG 0x1FF MOVLW 0xXX ORG 0x000 MOVWF OSCCAL Hope that this helps you, - Nick -