http://www.techonline.com/learning/course/212200220 Quite practical first hand information from the prototyping house people. And it matches well with what the downstairs manufacturing people tell us. You need register to access the site. I registered back in 1999 and I think it is a good website. Xiaofan -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist