> I believe that the current supplied by the RS232 is > not defined. So there is no guarantee enough power is > supplied. read the specs: both source voltage and impdance are defined (with a wide margin). whether read PCs adhere to the specs is another matter :( 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