Jeff, I am fully aware of the Microchip specifications as indicated by my comment "not-recommended by Microchip" within my post. Rather than speculating on what might be safe, you should try it and see it for yourself. These oscillator values have performed "reliably" for the majority of I/O functions including serial RS232. The less favorable characteristics of an RC oscillator at 32KHz are not present at 4MHz and there has not been a single incident of a stalling oscillator amongst 1,200 PCBs during exhaustive "burn in" testing. Sincerely, Ned Seith Nedtronics 59 3rd Street Gilroy, CA 95020 (408) 842-0858 ned@nedtron.com At 10:26 PM 8/16/01 -0400, you wrote: >----- Original Message ----- >From: Ned Seith > > > I use 4,700 ohms and 22pF with the 16F84 to produce 4 MHz. with the > > oscillator type set to "RC". > > > > These not-recommended by Microchip values work reliably, reduce cost (vs > > crystal) and reduce weight for model airplane receivers. > >Although they recommend R >= 5k Ohms, if you read the accompanying comments >in the data sheet, they say that with R <= 4k the oscillator may become >unstable, so 4.7k seems safe enough. > >Jeff > >-- >http://www.piclist.com hint: The list server can filter out subtopics >(like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.