John Pearson wrote: > What value resistor would be appropriate for a pullup on my 300 baud, > open collector serial port (no level shifting, just straight 5volt > logic levels at both ends) with a 6' audio cable. Battery operated so I > want a minimal value. Why are you specifying open collector? It doesn't seem to fit here. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads