> It would need at least 4 pins... clock and data for programming, plus > power/ground. So I guess you'd be stuck with two IO's instead. Nah; Doesn't Dallas have a perfectly reasonable one-wire data protocol? Some of the one-wire devices piggyback data on the Vcc, right? So maybe you can even have a two-pin device... BillW -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads