> right, good point, my guess is that the pc will have a clock > which is a multiple of the baud rate so that, as others have > said, with such a crystal there will be no error. Are willing to bet your neck on this? If not you'd better assume that the PC designer and you make the same assumptions, so each side can claim half of the error budget (that is, what's left of it after the transceivers, cable effects etc. have taken their part). Wouter van Ooijen -- ------------------------------------------- Van Ooijen Technische Informatica: www.voti.nl consultancy, development, PICmicro products docent Hogeschool van Utrecht: www.voti.nl/hvu -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist