> total cost = engineering cost + unit cost * number of units. Yes Wouter, but this doesn't apply to most hobbyists who do it because its fun and they want to learn something. The journey can be as much the reward as the destination. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.