At 04:44 PM 1/12/97 -0800, you wrote:
>I have a circuit that runs a PIC16C57 with the XT oscillator. When I
>program an erasable part, the 4 MHz clock crystal runs at a certain rate.
>When I burn the same code into an RC OTP part, the crystal runs at a rate
>that's different by several parts per million.
>
>Does anyone know why that would be?
>
>
>Bryan Mumford
>Santa Barbara, California

Well it could have something to do with the fact that during manufacture
the device was tested in XT mode and found to be too far out of tolarance
and therefore specified as a RC part. If you want accurate 16C57s in XT
mode, try buying XT/P parts.

I don't know, I'm only guessing but gee, it sounds like a good guess to me.

Jim