Hello to all, That's a question about diferences between HS and RC oscillator modes. I'd got a circuit with a 16F84-10/P running with a RC oscillator at 7.6 MHz (OSC/4=1.9 MHz, measured with an osciloscope), and it worked *FINE*. But I tried to "improve" its realiability and changed the RC osc by a 8 MHz ceramic resonator with built-in capacitors, modifing just the CONFIG word in the assembly file and changing the R and C by the resonator. Now, the application fails *sometimes*, and a piece of code that write the internal EEPROM has an erratic behaviour, writing in wrong locations, and wrong values. I've tried to change to the old configuration and everything works fine, so the PIC has not died. Reading the PIC data sheet, I've found just one difference: a 1024 TOCS delay time when weaking from sleep, but I'm not using the sleep feature. I'm desesperate :( ?Any sugestion? Thanks in advance, Adolfo. ----------------------------------------------------------------------- | Adolfo Cobo Garcia - UNIVERSIDAD DE CANTABRIA | | E.T.S.I.I. y Telecomunicacion, Grupo de Ingenieria Fotonica | | Avda. Los Castros s/n E-39005 Santander SPAIN | | Tfno. +34-42-201539 Fax +34-42-201873 Email: acobo@teisa.unican.es | -----------------------------------------------------------------------