Hi John,

In the datasheets, look for "Typical RC Oscillator Frequency vs. Vdd"
Graphs.  Each PIC should have 3 or so of them (at least they do in the 1995
databook and PIC16C8X datasheet I downloaded from the Web Site) plotting the
frequency for different Rs and Cs as well as operating voltages.

As you've stated in your note, you're comfortable +/- 50% which is about
what I found that they are capable in terms of accuracy (I have typically
found them to be about 30% accurate).  This means that the RC oscillator
can't be used for anything that even requires moderate accuracy.

Myke
>I have an application that has no need for accuracy (+-50% would be fine,
>but isn't needed :-), so I'd like to use the RC oscillator.  I don't have a
>prototype to check empirically, and the manuals say "see the device
>characterization sheets," which I can find neither in the manuals nor on the
>web site.
>
>How do I find the values without hardware to solder and test?
>
>
>john perry
>jperry@norfolk.infi.net
>
>

Do you ever feel like an XT Clone caught in the Pentium Pro Zone?