I tried removing the load resistor from the schematic, no difference. I removed the crystal, substituted a 4 MHz OSC, changed the firmware accordingly, and now the demo runs. I'm happy now, although I'd like to understand what's wrong with the original circuit. Anyway, wanted to say thanks for the suggestions. regards, --steve -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist