David VanHorn wrote: >The long term accuracy of the power grid is better than that >watch crystal. > > > Dave, Are you saying it is difficult to get 20-30 ppm accuracy out of a watch crystal in a real-world application, or just that the power grid is more accurate than that? Aaron -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist