Mister Happy wrote:
>
> Here is why I'm an idiot.
>
> I foolishly erased my JW pic (12c508a), and didn't write down the osccal
> value.  How can I get it back?  How many different combinations are there?
> One thing I thought of would be to "zero in" on the value. If its between 0
> and 255, then I might try 128, see how it works, then goto 64, and 196.
> then if 64 works best, try 32, and 96. then if 96 works best try 80, and
> 112.  and so on until I get close enough the the number thats it works.  How
> do I program these values back into the pic?
>
> Give me all of your osccal values, I'll take an average and see whats
> happens.
>
> PLEASE HELP.

Mr. Happy - -

Use this code:
;----------------
OscVal  EQU  0x80
     ;
     ORG     0x1FF
     MOVLW   OscVal
     ;
     ORG     0x000
     MOVWF   OSCCAL   ; OSCCAL is defined as 0x0005
     ; Your remaining startup code goes here.
     .
     .
     .
     END
;----------------
Then check your oscillator frequency and adjust OscVal up or down
in 0x10 steps as needed.  Next time you get a new JW part, check and
record the value at 0x1FF (0x3FF for a 519) as your _first_ step in
using it!

You should download the 508 data sheet:
  http://www.microchip.com/Download/Lit/PICmicro/12C5XX/40139e.pdf

Have fun,
 - Nick -