Quote Originally Posted by Joe S. View Post
You are sure the config statement is set to HS_OSC, Yes?
Ah ha, that might be it... I have the configuration word set to XT on the pull-down menu (I don't typically set the oscillator type in the program). I guess that should be set to HS. Odd that the previous 16f628a worked with the same oscillator on XT. I guess that XT occasionally works for 20Mhz xtals?

Thanks!
Dave